这是用户在 2024-11-2 15:28 为 https://wvpn.ustc.edu.cn/https/77726476706e69737468656265737421e0e2438f69316b4330079bab/doi/10.1021/... 保存的双语快照页面，由 沉浸式翻译 提供双语支持。了解如何保存？
ACS Publications. Most Trusted. Most Cited. Most Read
Raising Near-Infrared Photoluminescence Quantum Yield of Au42 Quantum Rod to 50% in Solutions and 75% in Films
More

OR SEARCH CITATIONS

My Activity
Publications
Recently Viewed

Figure 1Loading Img
Download Hi-Res ImageDownload to MS-PowerPointCite This:J. Am. Chem. Soc. 2024, 146, 41, 27993-27997
  • Open Access
Communication
通讯

Raising Near-Infrared Photoluminescence Quantum Yield of Au42 Quantum Rod to 50% in Solutions and 75% in Films
将 Au42 量子棒的近红外光致发光量子产率提高到 50% 在溶液中和 75%
Click to copy article link
点击复制文章链接Article link copied!

Open PDF 打开 PDFSupporting Information (1)
支持信息 （1）

Journal of the American Chemical Society

Cite this: J. Am. Chem. Soc. 2024, 146, 41, 27993–27997
Click to copy citationCitation copied!
https://doi.org/10.1021/jacs.4c11703
Published October 3, 2024

Copyright © 2024 The Authors. Published by American Chemical Society. This publication is licensed under

CC-BY 4.0 .

Abstract 抽象

Click to copy section link
单击以复制部分链接Section link copied!
High Resolution Image
Download MS PowerPoint Slide

Highly emissive gold nanoclusters (NCs) in the near-infrared (NIR) region are of wide interest, but challenges arise from the excessive nonradiative dissipation. Here, we demonstrate an effective suppression of the motions of surface motifs on the Au42(PET)32 rod (PET = 2-phenylethanethiolate) by noncoordinative interactions with amide molecules and accordingly raise the NIR emission (875/1045 nm peaks) quantum yield (QY) from 18% to 50% in deaerated solution at room temperature, which is rare in Au NCs. Cryogenic photoluminescence measurements indicate that amide molecules effectively suppress the vibrations associated with the Au–S staple motifs on Au42 and also enhance the radiative relaxation, both of which lead to stronger emission. When Au42 NCs are embedded in a polystyrene film containing amide molecules, the PLQY is further boosted to 75%. This research not only produces a highly emissive material but also provides crucial insights for the rational design of NIR emitters and advances the potential of atomically precise Au NCs for diverse applications.
近红外 （NIR） 区域中的高发射金纳米团簇 （NC） 引起了广泛的关注，但过度的非辐射耗散带来了挑战。在这里，我们证明了通过与酰胺分子的非配位相互作用有效抑制了 Au42（PET）32 棒（PET = 2-苯乙基乙酸盐）上表面基序的运动，并相应地在室温下将脱气溶液中的 NIR 发射（875/1045 nm 峰）量子产率 （QY） 从 18% 提高到 50%，这在 Au NC 中很少见。低温光致发光测量表明，酰胺分子有效抑制了与 Au-S 相关的振动Au42 上的主打图案，并且还增强了辐射弛豫，这两者都导致更强的发射。当 Au42 NC 嵌入含有酰胺分子的聚苯乙烯薄膜中时，PLQY 进一步提高到 75%。这项研究不仅生产出一种高发射材料，还为 NIR 发射器的合理设计提供了重要的见解，并推动了原子精确 Au NC 在各种应用中的潜力。

This publication is licensed under
本出版物已获得

CC-BY 4.0 .
  • cc licence
  • by licence
Copyright © 2024 The Authors. Published by American Chemical Society
版权所有 © 2024 The Authors。由美国化学学会出版

Subjects 科目

what are subjects

Luminophores emitting in the NIR region (800–1700 nm) window are increasingly valued across many fields, (1−5) such as bioimaging and NIR optics. (6−8) Thiolate-protected Aun(SR)m NCs (SR = thiolate) have recently emerged as a promising class of NIR-emissive materials. (9−15) These NCs feature a core–shell structure, (16−18) in which the inner Au(0) core is enclosed by Au(I)–SR “staple motifs”. The tailorable size, structure, and composition of Au NCs allow them to exhibit emission peaks across the visible to NIR range. (19−22) Moreover, their atomic precision aids in a deeper understanding of photophysical mechanisms, (23,24) facilitating the design of highly luminescent materials. Currently, a few highly luminescent NCs in the visible range have been reported, (25−30) but the NIR region is still difficult due to the energy gap law induced significant loss of excitation energy via nonradiative relaxation. (31,32) The photoluminescence quantum yield (PLQY) of NIR-emissive Au NCs is often below 1%, (33,34) except a few cases (15,21,35−40) under ambient conditions.
在 NIR 区域 （800–1700 nm） 窗口中发射的发光团在许多领域 （1-5） 中越来越受到重视，例如生物成像和 NIR 光学。（6−8） 硫酸盐保护的 Aun（SR）m NC （SR = thiolate） 最近成为一类很有前途的 NIR 发射材料。（9−15） 这些 NC 具有核壳结构，（16−18），其中内部 Au（0） 内核被 Au（I）-SR“主基序”包围。Au NC 的可定制尺寸、结构和组成使它们能够在可见光到 NIR 范围内显示发射峰。（19−22） 此外，它们的原子精度有助于更深入地理解光物理机制，（23,24） 有助于设计高发光材料。目前，已经报道了一些可见光范围内的高发光 NC （25−30），但由于能隙定律通过非辐射弛豫诱导了激发能量的显着损失，因此 NIR 区域仍然很困难。（31,32） 近红外发射 Au NC 的光致发光量子产率 （PLQY） 通常低于 1% （33,34），但在环境条件下，除了少数情况 （15,21,35-40）。

Enhancing the PLQY can be accomplished by increasing the radiative decay rate (kr) and/or decreasing the nonradiative decay rate (knr) according to the formula, PLQY=krkr+knr. In the case of Au NCs, given their significantly higher knr (105–107 s–1) than the kr (104–105 s–1), reducing the knr offers a greater opportunity for PLQY enhancement. (19,41,42) The PL properties of Au NCs have been recognized to be intricately linked to the Au(I)–SR “staple motifs”, thus, restricting motions associated with these surface motifs is generally an effective strategy for achieving higher PLQY by suppressing the knr. (5,43−45)
根据公式 ，可以通过增加辐射衰减率 （kr） 和/或降低非辐射衰减率 （knr） 来实现 PLQY PLQY=krkr+knr 的增强。在 Au NC 的情况下，鉴于它们的 knr （105–107 s–1） 明显高于 kr （104–105 s–1），降低 knr 为 PLQY 增强提供了更大的机会。（19,41,42） Au NC 的 PL 特性已被公认为与 Au（I）-SR“主要基序”有着错综复杂的联系，因此，限制与这些表面基序相关的运动通常是通过抑制 knr 来实现更高 PLQY 的有效策略。（5,43−45）

Here, we report a noncoordinating interaction strategy for the suppression of knr to enhance the NIR emission of rod-shaped Au42(PET)32 (PET = 2-phenylethanethiolate). Specifically, the nonradiative energy loss in Au42 is suppressed by the addition of amide-containing small molecules, thus improving the PLQY to 50% in solution at room temperature. Cryogenic PL analysis reveals that the vibrations associated with the Au–S staples on Au42 are suppressed by amide molecules. Moreover, when Au42 is embedded in a polymer film containing amide molecules, the PLQY is further boosted to 75% at room temperature.
在这里，我们报道了一种抑制 knr 以增强棒状 Au42（PET）32 （PET = 2-苯乙硫酸盐） 的 NIR 发射的非配位相互作用策略。具体来说，通过添加含酰胺的小分子来抑制 Au42 中的非辐射能量损失，从而在室温下将 PLQY 提高到溶液中的 50%。低温 PL 分析表明，酰胺分子抑制了与 Au42 上 Au-S 订书钉相关的振动。此外，当 Au42 嵌入含有酰胺分子的聚合物薄膜中时，PLQY 在室温下进一步提高到 75%。

The Au42 quantum rod was synthesized using a method of N-heterocyclic carbene (NHC)-mediated kinetic control reported by our group. (46) The Au42 structure shows a rod-shaped, hexagonal close-packed Au20 kernel protected by two pairs of interlocked Au4(PET)5 motifs (marked in green and light green) on the two ends and six monomeric Au(PET)2 motifs (marked in blue) on the body (Figure 1A). (34,47) The optical absorption spectrum of Au42 exhibits two major peaks at 375 and 806 nm (Figure 1B, green profile). Theoretical simulations identified that the 806 nm peak originates from the HOMO-to-LUMO transition and the transition dipole is strongly polarized along the longitudinal direction, while the 375 nm peak is not. (47)
Au42 量子棒是使用我们小组报道的 N-杂环卡宾 （NHC） 介导的动力学控制方法合成的。（46） Au42 结构显示了一个棒状、六边形的紧密堆积的 Au20 内核，两端有两对互锁的 Au4（PET）5 基序（标记为绿色和浅绿色），主体上有六个单体 Au（PET）2 基序（标记为蓝色）（图 1A）。（34,47） Au42 的光吸收光谱在 375 和 806 nm 处表现出两个主要峰（图 1B，绿色剖面）。理论模拟确定，806 nm 峰源自 HOMO 到 LUMO 的跃迁，跃迁偶极子沿纵向强烈极化，而 375 nm 峰则不是。

Figure 1 图 1

Figure 1. (A) Structure of Au42(PET)32. Color code: yellow = S, other colors = Au, carbon tails are omitted for clarity. (B) Optical absorption (green) and PL (blue) spectra of Au42 dissolved in C2Cl4. (C) Optical absorption spectra, (D) PL spectra, and (E) PLQY of Au42 dissolved in deaerated 2-MeTHF containing DMBA with different concentrations. (F) The kr and knr of S1 state of Au42 in deaerated 2-MeTHF containing DMBA with different concentrations. For PL measurements: both slit widths 8 nm.
图 1.（A） Au42（PET）32 的结构。颜色代码：黄色 = S，其他颜色 = Au，为清楚起见，省略了碳尾。（B） 溶解在 C2Cl4 中的 Au42 的光吸收（绿色）和 PL（蓝色）光谱。Au42 溶解在含有不同浓度 DMBA 的脱气 2-MeTHF 中的光吸收光谱、（D） PL 光谱和 （E） PLQY。（F） Au42 在含有不同浓度 DMBA 的脱气 2-MeTHF 中 S1 状态的 kr 和 knr。对于 PL 测量：两个狭缝宽度均为 8 nm。

High Resolution Image
Download MS PowerPoint Slide

Upon excitation at 806 nm, Au42 exhibits fluorescence and phosphorescence dual emission at 875 nm (denoted FL) and 1040 nm (PH) (Figure 1B, blue profile), respectively, with a total PLQY of 18% (Figure S1); note that this value is higher than the 12% reported earlier (46) due to the different excitation wavelengths (806 nm in this work versus 380 nm previously).
在 806 nm 激发时，Au42 分别在 875 nm（表示为 FL）和 1040 nm（PH）处表现出荧光和磷光双发射（图 1B，蓝色剖面），总 PLQY 为 18%（图 S1）;请注意，由于激发波长不同（本研究中为 806 nm，而之前为 380 nm），该值高于之前报道的 12% （46）。

When Au42 (0.1 OD at 806 nm, absorption coefficient ε806 = 1.08 × 105 M–1 cm–1, (48) i.e., 9.26 × 10–4 mM) was mixed with nonluminescent N,N-dimethylbenzamide (DMBA, Figure S2), the Au42 absorption profile remains unchanged, but its NIR absorption peak blueshifts from 806 to 781 nm with increasing amide concentration from 0 to 2143.9 mM (Figure 1C and Figure S3), and the integrated PL intensity of Au42 increases significantly by ∼3-fold (Figure 1D and Table S1), reaching a total PLQY of 50.1% (Figure 1E and Table S1). Specifically, the PLQY initially remains unchanged with the concentration up to 53.6 mM (Stage I). It then exhibits a gradual rise, reaching 50.1% at the DMBA concentration of 1286.4 mM (Stage II), and maintains this intensity as the concentration is further increased (Stage III). When Au42 was precipitated out of the solution to remove amides and redissolved in C2Cl4, the PLQY of Au42 recovers to the initial 18%, indicating noncoordinative interactions between Au42 and DMBA.
当 Au42（806 nm 处 0.1 OD，吸收系数ε 806 = 1.08 × 105 M–1 cm–1，（48） 即 9.26 × 10–4 mM）与非发光 N，N-二甲基苯甲酰胺（DMBA，图 S2）混合时，Au42 吸收曲线保持不变，但其 NIR 吸收峰从 806 到 781 nm，酰胺浓度从 0 增加到 2143.9 mM（图 1C 和图 S3），Au42 的积分 PL 强度显着增加约 3 倍（图 1D 和表 S1），达到 50.1% 的总 PLQY（图 1E 和表 S1）。具体来说，PLQY 最初保持不变，浓度高达 53.6 mM（I 期）。然后它逐渐升高，在 DMBA 浓度为 1286.4 mM 时达到 50.1%（II 期），并随着浓度的进一步增加（III 期）保持这种强度。当 Au42 从溶液中沉淀以去除酰胺并重新溶解在 C2Cl4 中时，Au42 的 PLQY 恢复到最初的 18%，表明 Au42 和 DMBA 之间存在非配位相互作用。

The dual PL bands are deconvoluted to analyze the respective variation of FL and PH (Figures S4 and S5 and Table S1). It is evident that the FL shows a dependence on the concentration of DMBA, but the PH remains constant. Generally, the FL enhancement can be accomplished either by increasing the kr and/or reducing the knr. Here, our results reveal a significant reduction in the knr for the FL of Au42 upon the addition of DMBA, plummeting from 13.51 × 108 s–1 to 3.33 × 108 s–1, together with a moderate increase in kr from 1.42 × 108 s–1 to 2.51 × 108 s–1 (Figure 1F and Table S1).
对双 PL 波段进行去卷积以分析 FL 和 PH 的相应变化（图 S4 和 S5 以及表 S1）。很明显，FL 显示出对 DMBA 浓度的依赖性，但 PH 保持不变。通常，FL 增强可以通过增加 kr 和/或减少 knr 来实现。在这里，我们的结果表明，添加 DMBA 后，Au42 的 FL 的 knr 显着降低，从 13.51 × 108 s–1 下降到 3.33 × 108 s–1，同时 kr 从 1.42 × 108 s–1 适度增加到 2.51 × 108 s–1（图 1F 和表 S1）。

We further conducted cryogenic PL measurements from room temperature to 80 K (Figure 2A and B). For the Au42/DMBA system, we selected a DMBA concentration of 857.6 mM to ensure a significant PL enhancement but preventing the precipitation of DMBA at low temperatures. Given the fact that Au NCs exhibit stronger absorption at low temperatures, we also performed temperature-dependent absorption (Figure S6) to correct PLQY at low temperatures. The cryogenic PL for Au42 and Au42/DMBA in 2-methyltetrahydrofuran (2-MeTHF) are shown in Figure 2A-B. The PLQY of Au42 (without DMBA) increases from 16.8% to 45.6% as the temperature is lowered from 298 to 80 K; note: 16.8% in 2-MeTHF (“glass” forming solvent) slightly differs from 18% in C2Cl4. For the Au42/DMBA, the PLQY rises from 45.7% to 89.1% in the same temperature range. The detailed results of peak deconvolution are provided in Tables S2 and S3. Both FL and PH intensities for the two systems increase as the temperature decreases, in contrast to the sole FL enhancement by amide. The FL for the Au42/DMBA system is consistently higher than that of Au42 (Figure 2C). Conversely, the PH emission remains nearly identical for the two systems at each temperature, though the PH increases at lower temperatures (Figure S7). The PL excitation spectra for Au42 and Au42/DMBA were also compared (Figures S8 and S9). The PL excitation at 80 K shows a blue shift compared to that at 298 K, consistent with the cryogenic absorption (Figure S6A).
我们进一步进行了从室温到 80 K 的低温 PL 测量（图 2A 和 B）。对于 Au42/DMBA 系统，我们选择了 857.6 mM 的 DMBA 浓度，以确保显着增强 PL，但防止 DMBA 在低温下沉淀。鉴于 Au NC 在低温下表现出更强的吸收，我们还进行了温度依赖性吸收（图 S6）以校正低温下的 PLQY。2-甲基四氢呋喃 （2-MeTHF） 中 Au42 和 Au42/DMBA 的低温 PL 如图 2AB 所示。随着温度从 298 K 降低到 80 K，Au42（不含 DMBA）的 PLQY 从 16.8% 增加到 45.6%;注：2-MeTHF（“玻璃”形成溶剂）中的 16.8% 与 C2Cl4 中的 18% 略有不同。对于金42/DMBA，在相同的温度范围内，PLQY 从 45.7% 上升到 89.1%。峰值反卷积的详细结果如表 S2 和 S3 所示。这两个系统的 FL 和 PH 强度都随着温度的降低而增加，这与酰胺的唯一 FL 增强形成鲜明对比。Au42/DMBA 系统的 FL 始终高于 Au42 的 FL（图 2C）。相反，两个系统的 PH 发射在每个温度下几乎相同，尽管 PH 值在较低温度下增加（图 S7）。还比较了 Au42 和 Au42/DMBA 的 PL 激发光谱（图 S8 和 S9）。与 298 K 相比，80 K 时的 PL 激发显示出蓝移，与低温吸收一致（图 S6A）。

Figure 2 图 2

Figure 2. Temperature-dependent PL spectra of (A) Au42 and (B) Au42/DMBA (857.6 mM) in 2-MeTHF under a He atmosphere. Inset: the variation of total PLQY as the temperature decreases from 298 to 80 K. For PL measurements: excitation at 806 and 781 nm for Au42 and Au42/DMBA (857.6 mM), respectively, slit width 8 nm, and emission slit 8 nm. (C) Variation of QY of FL for Au42 and Au42/DMBA from 298 to 80 K. (D) Plot of kr (green symbols) and knr (yellow symbols) from 80 to 298 K. (E) Normalized integrated intensities of FL for Au42 and Au42/DMBA and fitting using eq 1 (data from panel C). (F) fwhm of the FL as a function of temperature for Au42 and Au42/DMBA and fitting using eq 2. Both eqs 1 and 2 are in the text.
图 2.在 He 气氛下，（A） Au42 和 （B） Au42/DMBA （857.6 mM） 在 2-MeTHF 中的温度依赖性 PL 光谱。插图：随着温度从 298 K 降低到 80 K，总 PLQY 的变化。对于 PL 测量：Au42 和 Au42/DMBA （857.6 mM） 在 806 和 781 nm 处激发，狭缝宽度为 8 nm，发射狭缝为 8 nm。（C） Au42 和 Au42/DMBA 的 FL QY 从 298 到 80 K 的变化。（D） kr（绿色符号）和 knr（黄色符号）从 80 到 298 K 的图。（E） Au42 和 Au42/DMBA 的 FL 归一化积分强度，并使用方程 1 进行拟合（数据来自图 C）。（F） Au42 和 Au42/DMBA 的 FL fwhm 随温度的变化，并使用方程 2 进行拟合。方程 1 和 2 都在文本中。

High Resolution Image
Download MS PowerPoint Slide

We further compared the kr and knr of the FL for both Au42 and Au42/DMBA systems at low temperatures (Figure 2D). The kr values for both systems remain relatively constant, but the knr values for both Au42 and Au42/DMBA exhibit a notable decrease, attributed to the suppression of staple vibrations at low temperatures; note: the core vibrations are typically manifested at even lower temperatures than 80 K. (49) Additionally, it is important to highlight that the knr of Au42/DMBA is significantly lower than that of Au42 at the same temperatures. To elucidate the mechanism underlying the decrease in knr of FL upon the addition of DMBA, we fitted the temperature-dependent FL intensity evolution by eq 1 (50)
我们进一步比较了低温下 Au42 和 Au42/DMBA 系统FL的kr和knr（图2D）。两种系统的 kr 值保持相对恒定，但 Au42 和 Au42/DMBA 的 knr 值都表现出显着下降，这归因于低温下对订书钉振动的抑制;注：磁芯振动通常在低于 80 K 的温度下表现出来。（49） 此外，需要强调的是，在相同温度下，Au42/DMBA 的 knr 明显低于 Au42。为了阐明添加 DMBA 后 FL 的 knr 降低的机制，我们用方程 1（50） 拟合了温度依赖性的 FL 强度演变

I(T)=I01+ae−E/kBT
(1)
where I0 represents the initial intensity, a denotes the ratio of nonradiative and radiative probabilities, and E is the activation energy for the nonradiative relaxation. Here, only one dominant phonon-assisted nonradiative channel is considered in this modeling. The corresponding fitting line and parameters are shown in Figure 2E, where the activation energies of phonon modes that coupled with the FL of Au42 and Au42/DMBA are determined to be 38.9 and 22.3 meV, respectively; note: 1 meV = 8 cm–1. This suggests that the addition of DMBA suppresses the vibrations associated with the Au–S staples on the Au42. Meanwhile, the a value falls drastically from 4.5 to 1.6, also indicating a significant suppression of the staple vibration-induced nonradiative decay. Moreover, we extracted and compared the temperature-dependent full-width at half-maximum (fwhm) values for Au42 and Au42/DMBA (Figure 2F). Generally, both acoustic phonon modes (low energy) and optical phonon modes (high energy) contribute to the broadening of PL line width, but our experiments are conducted down to 80 K only ─ where the contributions from acoustic phonons are trivial and can be omitted, thus we only consider the optical phonon factor to model the line width broadening by eq 2 (24)
其中 I0 表示初始强度，a 表示非辐射和辐射概率的比率，E 是非辐射弛豫的活化能。在这里，在此建模中只考虑了一个占主导地位的声子辅助非辐射通道。相应的拟合线和参数如图 2E 所示，其中与 Au42 和 Au42/DMBA 的 FL 耦合的声子模式的活化能分别为 38.9 和 22.3 meV;注意：1 meV = 8 cm–1。这表明 DMBA 的添加抑制了与 Au42 上的 Au-S 订书钉相关的振动。同时，a 值从 4.5 急剧下降到 1.6，这也表明显着抑制了订书钉振动引起的非辐射衰减。此外，我们提取并比较了 Au42 和 Au42/DMBA 的温度依赖性半峰全宽 （fwhm） 值（图 2F）。通常，声子模式（低能量）和光学声子模式（高能量）都有助于 PL 线宽的展宽，但我们的实验仅进行到 80 K——其中声子的贡献很小，可以省略，因此我们只考虑光声子因子来模拟线宽展宽方程 2（24）
Γ(T)=Γ0+γLO1eELO/kBT−1
(2)
where Γ0 is the temperature-independent intrinsic line width, γLO refers to the coupling coefficient of electrons with longitudinal optical (LO) phonons, and ELO denotes the average energy for coupled LO phonon modes. The modeling results (Figure 2F) reveal that the average LO phonon energies for Au42 and Au42/DMBA are 30 and 15 meV, respectively. The reduced phonon energy in Au42/DMBA aligns with the eq 1 fitting analysis, indicating a suppression of surface vibrations. Meanwhile, the coupling strength for Au42/DMBA (γLO = 43 meV) is much lower than that for Au42 (γLO = 132 meV), suggesting a diminished electron–phonon interaction in the Au42/DMBA system.
其中Γ0 是与温度无关的固有线宽，γLO 是指电子与纵向光学 （LO） 声子的耦合系数，ELO 表示耦合 LO 声子模式的平均能量。建模结果（图 2F）显示，Au42 和 Au42/DMBA 的平均 LO 声子能量分别为 30 和 15 meV。Au42/DMBA 中声子能量的降低与 eq 1 拟合分析一致，表明表面振动受到抑制。同时，Au42/DMBA 的耦合强度 （γLO = 43 meV） 远低于 Au42 （γLO = 132 meV），表明 Au42/DMBA 系统中的电子-声子相互作用减弱。

The high PLQY (50%) of Au42/DMBA in the NIR region is rare among the reported Au NCs (Figure S10). In addition to DMBA, we found that other amide molecules (Figure 3A), such as N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), and N-methylformanilide (NMFA), have similar effects on Au42, including (i) the longitudinal absorption peak of Au42 at 806 nm undergoes a blueshift when mixed with these molecules (Figure S11), and (ii) a significant enhancement of the PLQY of Au42 is observed (Figure S12 and Table S4), e.g., 29.3% for DMF, 47.0% for DMAc, and 55.8% for NMFA. The peak deconvolution analysis (Figure S13) further indicates that these amides predominantly boost the FL (Figure 3B) but not the PH. Additionally, the observed increase in FL intensity is primarily attributed to the suppression of nonradiative relaxation (Figure 3B).
NIR 区域中 Au42/DMBA 的高 PLQY （50%） 在已报道的 Au NC 中是罕见的（图 S10）。除了 DMBA 之外，我们还发现其他酰胺分子（图 3A），如 N，N-二甲基甲酰胺 （DMF）、N，N-二甲基乙酰胺 （DMAc） 和 N-甲基甲酰苯胺 （NMFA），对 Au42 具有类似的影响，包括 （i） Au42 在 806 nm 处的纵向吸收峰在与这些分子混合时发生蓝移（图 S11），以及 （ii） 观察到 Au42 的 PLQY 显着增强（图 S12 和表 S4），例如 DMF 为 29.3%，DMAc 为 47.0%，NMFA 为 55.8%。峰值反卷积分析（图 S13）进一步表明，这些酰胺主要提高 FL（图 3B），但不提高 PH。此外，观察到的 FL 强度增加主要归因于对非辐射弛豫的抑制（图 3B）。

Figure 3 图 3

Figure 3. (A) Structures of different small molecules. (B) QYs (bars) and knr (blue symbols) for Au42 mixed with different molecules.
图 3.（A） 不同小分子的结构。（B） Au42 与不同分子混合的 QY（条形）和 knr（蓝色符号）。

High Resolution Image
Download MS PowerPoint Slide

To pinpoint the specific atoms in the amide group accountable for the PL enhancement, we tested two small molecules composed of only nitrogen or oxygen atom, e.g., N,N-dimethylaniline (DMA) and acetylacetone (AA), but neither molecule nor their mixture induced any blueshift in the longitudinal absorption peak of Au42 (Figure S14), nor did they enhance the PL intensity of Au42 (Figure S15 and Table S4). This comparison underscores a cooperative effect of nitrogen and oxygen atoms of amides on the PL enhancement of Au42 while retaining its structure (Figure S16).
为了确定酰胺组中负责 PL 增强的特定原子，我们测试了两个仅由氮或氧原子组成的小分子，例如 N，N-二甲基苯胺 （DMA） 和乙酰丙酮 （AA），但分子和它们的混合物都没有在 Au42 的纵向吸收峰中诱导任何蓝移（图 S14），也没有增强 Au42 的 PL 强度（图 S15 和表 S4).这种比较强调了酰胺的氮原子和氧原子对 Au42 的 PL 增强的协同作用，同时保持其结构（图 S16）。

The amide molecules can further enhance the emission of Au42 embedded in a polymer film. As illustrated in Figure S17, the PLQY of sole Au42 increases from 18% to 52% when embedded in polystyrene (PS) films, and it is further elevated to 75% with the addition of DMBA into the Au42/PS film at room temperature. This highly emissive film holds promise in applications such as NIR optoelectronic devices and security as well as quantum telecom.
酰胺分子可以进一步增强嵌入聚合物薄膜中的 Au42 的发射。如图 S17 所示，当嵌入聚苯乙烯 （PS） 薄膜中时，比目鱼 Au42 的 PLQY 从 18% 增加到 52%，在室温下向 Au42/PS 薄膜中添加 DMBA 后，PLQY 进一步提高到 75%。这种高发射薄膜在 NIR 光电器件和安全以及量子电信等应用中大有可为。

In summary, we report an effective strategy involving noncoordinative interactions between amides and Au42 to achieve high PLQY (50% in solutions and 75% in films) in the NIR range by significantly reducing the nonradiative decay rate. This method is also effective for other Aun quantum rods. (48) Our findings offer inspirations for strategically designing highly efficient NIR emitters, opening new avenues for the use of engineered nanoclusters in diverse applications.
总之，我们报道了一种涉及酰胺和 Au42 之间非配位相互作用的有效策略，通过显著降低非辐射衰变率，在 NIR 范围内实现高 PLQY（溶液中为 50%，薄膜中为 75%）。这种方法对其他 Aun 量子棒也有效。（48） 我们的研究结果为战略性地设计高效 NIR 发射器提供了灵感，为工程纳米团簇在各种应用中的使用开辟了新的途径。

Supporting Information 支持信息

Click to copy section link
单击以复制部分链接Section link copied!

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/jacs.4c11703.
支持信息可在 https://pubs.acs.org/doi/10.1021/jacs.4c11703 免费获取。

  • Details of the synthesis and data analysis and additioanl figures and tables as described in the text (PDF)
    文中描述的综合和数据分析的详细信息以及附加图形和表格 （PDF）

Terms & Conditions  条款和条件

Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.
大多数电子支持信息文件无需订阅 ACS Web 版本即可获得。此类文件可以按文章下载用于研究用途（如果有链接到相关文章的公共使用许可证，则该许可证可能允许其他用途）。可以通过 RightsLink 权限系统请求 ACS 以用于其他用途：http://pubs.acs.org/page/copyright/permissions.html。

Author Information 作者信息

Click to copy section link
单击以复制部分链接Section link copied!

Acknowledgments

Click to copy section linkSection link copied!

R.J. acknowledges financial support from NSF (DMR #2419539) for this research.

References

Click to copy section linkSection link copied!

This article references 50 other publications.

  1. 1
    Sharma, A.; Verwilst, P.; Li, M.; Ma, D.; Singh, N.; Yoo, J.; Kim, Y.; Yang, Y.; Zhu, J. H.; Huang, H.; Hu, X. L.; He, X. P.; Zeng, L.; James, T. D.; Peng, X.; Sessler, J. L.; Kim, J. S. Theranostic Fluorescent Probes. Chem. Rev. 2024, 124, 2699– 2804,  DOI: 10.1021/acs.chemrev.3c00778
    View
    Google Scholar
    There is no corresponding record for this reference.
  2. 2
    Lei, Z.; Zhang, F. Molecular Engineering of NIR-II Fluorophores for Improved Biomedical Detection. Angew. Chem., Int. Ed. 2021, 60, 16294– 16308,  DOI: 10.1002/anie.202007040
    View
    Google Scholar
    2
    Molecular Engineering of NIR-II Fluorophores for Improved Biomedical Detection
    Lei, Zuhai; Zhang, Fan
    Angewandte Chemie, International Edition (2021), 60 (30), 16294-16308CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
    A review. The development of fluorophores for the second near-IR window (NIR-II, 1000-1700 nm) represents an emerging, significant, and vibrant field in analytic chem., chem. biol., and biomedical engineering. The wavelength, brightness, and stability are three crucial factors that det. the performance of an NIR-II fluorophore. Up to now, significant progress has been made in the development of NIR-II fluorescence mol. probes, including the synthesis of D-A-D and D-π-A fluorophores with improved NIR-II fluorescence imaging performance and the construction of off-on probes and ratiometric probes via energy transfer or mol. structure modification. In this review, we summarize the most recent advances in mol. engineering design strategies of NIR-II fluorophores and probes, then highlight a selection of bioimaging and biosensing applications. We also provide perspectives on potential challenges and opportunities in this emerging field.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXhvVSju78%253D&md5=847e2a9e3739ae3e6b60447f09e276ff
  3. 3
    Zampetti, A.; Minotto, A.; Cacialli, F. Near-Infrared (NIR) Organic Light-Emitting Diodes (OLEDs): Challenges and Opportunities. Adv. Funct. Mater. 2019, 29, 1807623,  DOI: 10.1002/adfm.201807623
    View
    Google Scholar
    There is no corresponding record for this reference.
  4. 4
    Liu, H.; Hong, G.; Luo, Z.; Chen, J.; Chang, J.; Gong, M.; He, H.; Yang, J.; Yuan, X.; Li, L.; Mu, X.; Wang, J.; Mi, W.; Luo, J.; Xie, J.; Zhang, X.-D. Atomic-Precision Gold Clusters for NIR-II Imaging. Adv. Mater. 2019, 31, 1901015,  DOI: 10.1002/adma.201901015
    View
    Google Scholar
    4
    Atomic-Precision Gold Clusters for NIR-II Imaging
    Liu, Haile; Hong, Guosong; Luo, Zhentao; Chen, Junchi; Chang, Junlei; Gong, Ming; He, Hua; Yang, Jiang; Yuan, Xun; Li, Lulin; Mu, Xiaoyu; Wang, Junying; Mi, Wenbo; Luo, Jian; Xie, Jianping; Zhang, Xiao-Dong
    Advanced Materials (Weinheim, Germany) (2019), 31 (46), 1901015CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
    Near-IR II (NIR-II) imaging at 1100-1700 nm shows great promise for medical diagnosis related to blood vessels because it possesses deep penetration and high resoln. in biol. tissue. Unfortunately, currently available NIR-II fluorophores exhibit slow excretion and low brightness, which prevents their potential medical applications. An at.-precision gold (Au) cluster with 25 gold atoms and 18 peptide ligands is presented. The Au25 clusters show emission at 1100-1350 nm and the fluorescence quantum yield is significantly increased by metal-atom doping. Bright gold clusters can penetrate deep tissue and can be applied in in vivo brain vessel imaging and tumor metastasis. Time-resolved brain blood-flow imaging shows significant differences between healthy and injured mice with different brain diseases in vivo. High-resoln. imaging of cancer metastasis allows for the identification of the primary tumor, blood vessel, and lymphatic metastasis. In addn., gold clusters with NIR-II fluorescence are used to monitor high-resoln. imaging of kidney at a depth of 0.61 cm, and the quant. measurement shows 86% of the gold clusters are cleared from body without any acute or long-term toxicity at a dose of 100 mg kg-1.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhvFSitL7E&md5=d719ced7f75e52e3901335fa54c31c88
  5. 5
    Wan, X. K.; Han, X. S.; Guan, Z. J.; Shi, W. Q.; Li, J. J.; Wang, Q. M. Interplay of Kernel Shape and Surface Structure for NIR Luminescence in Atomically Precise Gold Nanorods. Nat. Commun. 2024, 15, 7214,  DOI: 10.1038/s41467-024-51642-w
    View
    Google Scholar
    There is no corresponding record for this reference.
  6. 6
    Ma, H.; Wang, J.; Zhang, X.-D. Near-Infrared II Emissive Metal Clusters: from Atom Physics to Biomedicine. Coord. Chem. Rev. 2021, 448, 214184,  DOI: 10.1016/j.ccr.2021.214184
    View
    Google Scholar
    6
    Near-infrared II emissive metal clusters: From atom physics to biomedicine
    Ma, Huizhen; Wang, Junying; Zhang, Xiao-Dong
    Coordination Chemistry Reviews (2021), 448 (), 214184CODEN: CCHRAM; ISSN:0010-8545. (Elsevier B.V.)
    A review. Near-IR II (NIR-II) imaging at 1100-1700 nm supports deep tissue penetration, low auto-fluorescence interruption, and high imaging resoln. due to advances in attenuating photon scattering and absorption. For example, semiconductor quantum dots and carbon nanotubes as pioneer mol. probes were used for hind limbs and cerebrovascular imaging, and org. small mols. and polymers were employed for ultrafast and three-dimensional tumor vasculature imaging. Compared with the reported NIR-II fluorescence probe systems, the at.-precision metal clusters with unambiguous geometry structure can make the most of the spatial coordination of metal atoms by artificial atom manipulation, thus improving the luminescent quantum yield with tunable emission wavelength. Meanwhile, the water sol., renal cleanable, and highly stable features make them promising candidates for in vivo imaging. In this review, we aim to summarize the mol. and electronic structure, and optical properties of NIR-II emissive metal clusters. Meanwhile, we highlight their applications in brain, kidney, gastrointestinal imaging and tumor metastasis monitoring. We particularly reviewed recent advances on the biosafety of gold clusters at ultrahigh concn. Present work will promote the development of NIR-II imaging and make a step toward the clin. application.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXhvFyhsLjO&md5=14d54c66391495e3cb4d9dd57928fb6e
  7. 7
    Wang, F.; Zhong, Y.; Bruns, O.; Liang, Y.; Dai, H. In vivo NIR-II Fluorescence Imaging for Biology and Medicine. Nat. Photonics 2024, 18, 535– 547,  DOI: 10.1038/s41566-024-01391-5
    Google Scholar
    There is no corresponding record for this reference.
  8. 8
    Du, B.; Jiang, X.; Das, A.; Zhou, Q.; Yu, M.; Jin, R.; Zheng, J. Glomerular Barrier Behaves as an Atomically Precise Bandpass Filter in a Sub-Nanometre Regime. Nat. Nanotechnol. 2017, 12, 1096– 1102,  DOI: 10.1038/nnano.2017.170
    Google Scholar
    8
    Glomerular barrier behaves as an atomically precise bandpass filter in a sub-nanometre regime
    Du, Bujie; Jiang, Xingya; Das, Anindita; Zhou, Qinhan; Yu, Mengxiao; Jin, Rongchao; Zheng, Jie
    Nature Nanotechnology (2017), 12 (11), 1096-1102CODEN: NNAABX; ISSN:1748-3387. (Nature Research)
    The glomerular filtration barrier is known as a 'size cutoff' slit, which retains nanoparticles or proteins larger than 6-8 nm in the body and rapidly excretes smaller ones through the kidneys. However, in the sub-nanometer size regime, we have found that this barrier behaves as an atomically precise 'bandpass' filter to significantly slow down renal clearance of few-atom gold nanoclusters (AuNCs) with the same surface ligands but different sizes (Au18, Au15 and Au10-11). Compared to Au25 (∼1.0 nm), just few-atom decreases in size result in four- to ninefold redns. in renal clearance efficiency in the early elimination stage, because the smaller AuNCs are more readily trapped by the glomerular glycocalyx than larger ones. This unique in vivo nano-bio interaction in the sub-nanometer regime also slows down the extravasation of sub-nanometer AuNCs from normal blood vessels and enhances their passive targeting to cancerous tissues through an enhanced permeability and retention effect. This discovery highlights the size precision in the body's response to nanoparticles and opens a new pathway to develop nanomedicines for many diseases assocd. with glycocalyx dysfunction.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhsVKlu7fN&md5=2f0c1bbabc9acf9b07e9fcb75ee99e47
  9. 9
    Li, Y.; Zhou, M.; Song, Y.; Higaki, T.; Wang, H.; Jin, R. Double-Helical Assembly of Heterodimeric Nanoclusters into Supercrystals. Nature 2021, 594, 380– 384,  DOI: 10.1038/s41586-021-03564-6
    Google Scholar
    9
    Double-helical assembly of heterodimeric nanoclusters into supercrystals
    Li, Yingwei; Zhou, Meng; Song, Yongbo; Higaki, Tatsuya; Wang, He; Jin, Rongchao
    Nature (London, United Kingdom) (2021), 594 (7863), 380-384CODEN: NATUAS; ISSN:0028-0836. (Nature Portfolio)
    DNA has long been used as a template for the construction of helical assemblies of inorg. nanoparticles1-5. For example, gold nanoparticles decorated with DNA (or with peptides) can create helical assemblies6-9. But without such biol. ligands, helixes are difficult to achieve and their mechanism of formation is challenging to understand10,11. Atomically precise nanoclusters that are protected by ligands such as thiolate12,13 have demonstrated hierarchical structural complexity in their assembly at the interparticle and intraparticle levels, similar to biomols. and their assemblies14. Furthermore, carrier dynamics can be controlled by engineering the structure of the nanoclusters15. But these nanoclusters usually have isotropic structures16,17 and often assemble into commonly found supercrystals18. Here we report the synthesis of homodimeric and heterodimeric gold nanoclusters and their self-assembly into superstructures. While the homodimeric nanoclusters form layer-by-layer superstructures, the heterodimeric nanoclusters self-assemble into double- and quadruple-helical superstructures. These complex arrangements are the result of two different motif pairs, one pair per monomer, where each motif bonds with its paired motif on a neighboring heterodimer. This motif pairing is reminiscent of the paired interactions of nucleobases in DNA helixes. Meanwhile, the surrounding ligands on the clusters show doubly or triply paired steric interactions. The helical assembly is driven by van der Waals interactions through particle rotation and conformational matching. Furthermore, the heterodimeric clusters have a carrier lifetime that is roughly 65 times longer than that of the homodimeric clusters. Our findings suggest new approaches for increasing complexity in the structural design and engineering of precision in supercrystals.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXhtleqsLvN&md5=eead4fc70b29dfddacaf1ea2b94f57c4
  10. 10
    Kang, X.; Zhu, M. Tailoring the Photoluminescence of Atomically Precise Nanoclusters. Chem. Soc. Rev. 2019, 48, 2422– 2457,  DOI: 10.1039/C8CS00800K
    Google Scholar
    10
    Tailoring the photoluminescence of atomically precise nanoclusters
    Kang, Xi; Zhu, Manzhou
    Chemical Society Reviews (2019), 48 (8), 2422-2457CODEN: CSRVBR; ISSN:0306-0012. (Royal Society of Chemistry)
    A review. Due to their atomically precise structures and intriguing chem./phys. properties, metal nanoclusters are an emerging class of modular nanomaterials. Photo-luminescence (PL) is one of their most fascinating properties, due to the plethora of promising PL-based applications, such as chem. sensing, bio-imaging, cell labeling, phototherapy, drug delivery, and so on. However, the PL of most current nanoclusters is still unsatisfactory-the PL quantum yield (QY) is relatively low (generally lower than 20%), the emission lifetimes are generally in the nanosecond range, and the emitted color is always red (emission wavelengths of above 630 nm). To address these shortcomings, several strategies have been adopted, and are reviewed herein: capped-ligand engineering, metallic kernel alloying, aggregation-induced emission, self-assembly of nanocluster building blocks into cluster-based networks, and adjustments on external environment factors. We further review promising applications of these fluorescent nanoclusters, with particular focus on their potential to impact the fields of chem. sensing, bio-imaging, and bio-labeling. Finally, scope for improvements and future perspectives of these novel nanomaterials are highlighted as well. Our intended audience is the broader scientific community interested in the fluorescence of metal nanoclusters, and our review hopefully opens up new horizons for these scientists to manipulate PL properties of nanoclusters. This review is based on publications available up to Dec. 2018.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXkt1Wqt7k%253D&md5=a25d2e3afdc1a6d81551c0edc0d36b02
  11. 11
    Biswas, S.; Das, A. K.; Mandal, S. Surface Engineering of Atomically Precise M(I) Nanoclusters: From Structural Control to Room Temperature Photoluminescence Enhancement. Acc. Chem. Res. 2023, 56, 1838– 1849,  DOI: 10.1021/acs.accounts.3c00176
    Google Scholar
    11
    Surface Engineering of Atomically Precise M(I) Nanoclusters: From Structural Control to Room Temperature Photoluminescence Enhancement
    Biswas, Sourav; Das, Anish Kumar; Mandal, Sukhendu
    Accounts of Chemical Research (2023), 56 (13), 1838-1849CODEN: ACHRE4; ISSN:0001-4842. (American Chemical Society)
    A review is presented on the structural control and Photoluminescence enhancement through surface engineering of atomically precise M(I) nanoclusters. Understanding the structural architecture of nanoparticles is essential for investigating their fundamental properties because these materials have become more desirable in modern nanoscience research. Designing a proper synthetic strategy to control their growth with at. precision is crucial. The polydispersed nature of the nanoparticles makes detg. their precise structural information challenging. Metal nanoclusters (NCs) have emerged as a promising soln. to this problem as they bridge the gap between metal nanoparticles and discrete mol. complexes. Well-ordered mol. structures provide opportunities to look at structure-property correlations and find quantum confinement effects at the at. level that reveal their similarity to mol.-like properties. While most M(0)/(I)-based NCs exhibit exceptional photoluminescence (PL) emission at room temp., M(I)-based NCs are less likely to exhibit PL emissions due to their electronic environment. Developments in the field of metal nanoparticles have made it intriguing to achieve room-temp. PL emission in M(I) NCs. Efforts have focused on developing efficient methods for prepg. luminescent M(I) NCs to better comprehend fundamental aspects of their PL emission properties. The authors provide an overview of various synthetic strategies for prepg. NCs and their selective functionalization for generating room-temp. PL emissions. The authors' focus was creating an Ag(I) NC with a core-shell architecture, as this unique structural design complements the charge transition phenomenon. The mol. structure obtained from single-crystal x-ray diffraction (SCXRD) and assocd. theor. calcn. revealed that the authors' effort results in a unique hexagonal closed pack core and Keplerate shell contg. [S@Ag50S12(StBu)20]4+ NC where the charge transition between the core and the metal-ligand shell facilitates emission properties. The authors also explored the approach of host-guest supramol. adduct formations to engineer the surface of ligands that reduce nonradiative relaxation rates by restricting surface mol. vibrations and controlling the generation of PL emission. To do this, the authors capped precisely structured [Cl@Ag16S(S-Adm)8(CF3COO)5(DMF)3(H2O)2]·DMF with β-cyclodextrin via adamantane moieties. The authors also describe the effects of bimetallic cluster formation on increasing surface rigidity and modulating the frontier MO arrangement, which helps to attain synergy to generate room-temp. PL emission. The authors focused on the structural integrity of Ag(I) NCs, allowing the authors to incorporate heterometal atoms at peripheral positions that give [CO2@Ag20Cu2S2(StBu)10(CF3COO)8(DMA)4]·(DMA). The authors also explored the impact of introducing extra ligands into the Ag(I) cluster node on the generation of PL emission at room-temp. These strategies are not limited to Ag NCs. The authors discussed the possibility of combining core-shell architecture and surface modifications to enhance PL emission in [Cu18H3(S-Adm)12(PPh3)4Cl2] NC at room temp. SCXRD studies revealed its distinct core-shell architecture that ensures electronic transitions and that transition is controlled by the imposed surface rigidity that yields a higher PL emission. The authors believe that this innovative structural engineering holds potential for the advancement of NC research, and this Account will inspire the scientific community to synthesize functional M(I) NCs.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXht1Oms73L&md5=9cc1e1e53a9761366813b35dae742939
  12. 12
    Lin, H.; Song, X.; Chai, O. J. H.; Yao, Q.; Yang, H.; Xie, J. Photoluminescent Characterization of Metal Nanoclusters: Basic Parameters, Methods, and Applications. Adv. Mater. 2024, 36, e2401002  DOI: 10.1002/adma.202401002
    Google Scholar
    There is no corresponding record for this reference.
  13. 13
    Albright, E. L.; Levchenko, T. I.; Kulkarni, V. K.; Sullivan, A. I.; DeJesus, J. F.; Malola, S.; Takano, S.; Nambo, M.; Stamplecoskie, K.; Hakkinen, H.; Tsukuda, T.; Crudden, C. M. N-Heterocyclic Carbene-Stabilized Atomically Precise Metal Nanoclusters. J. Am. Chem. Soc. 2024, 146, 5759– 5780,  DOI: 10.1021/jacs.3c11031
    Google Scholar
    13
    N-Heterocyclic Carbene-Stabilized Atomically Precise Metal Nanoclusters
    Albright, Emily L.; Levchenko, Tetyana I.; Kulkarni, Viveka K.; Sullivan, Angus I.; DeJesus, Joseph F.; Malola, Sami; Takano, Shinjiro; Nambo, Masakazu; Stamplecoskie, Kevin; Hakkinen, Hannu; Tsukuda, Tatsuya; Crudden, Cathleen M.
    Journal of the American Chemical Society (2024), 146 (9), 5759-5780CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
    This perspective highlights advances in the prepn. and understanding of metal nanoclusters stabilized by org. ligands with a focus on N-heterocyclic carbenes (NHCs). We demonstrate the need for a clear understanding of the relationship between NHC properties and their resulting metal nanocluster structure and properties. We emphasize the importance of balancing nanocluster stability with the introduction of reactive sites for catalytic applications and the importance of a better understanding of how these clusters interact with their environments for effective use in biol. applications. The impact of atom-scale simulations, development of at. interaction potentials suitable for large-scale mol. dynamics simulations, and a deeper understanding of the mechanisms behind synthetic methods and phys. properties (e.g., the bright fluorescence displayed by many clusters) are emphasized.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB2cXjsleisbc%253D&md5=1a22399ab03078760e3f67e3c14e8aec
  14. 14
    Huang, Y.-Z.; Gupta, R. K.; Luo, G.-G.; Zhang, Q.-C.; Sun, D. Luminescence Thermochromism in Atomically Precise Silver Custers: A Comprehensive Review. Coord. Chem. Rev. 2024, 499, 215508,  DOI: 10.1016/j.ccr.2023.215508
    Google Scholar
    There is no corresponding record for this reference.
  15. 15
    Shi, W.-Q.; Zeng, L.; He, R.-L.; Han, X.-S.; Guan, Z.-J.; Zhou, M.; Wang, Q.-M. Near-Unity NIR Phosphorescent Quantum Yield from a Room-Temperature Solvated Metal Nanocluster. Science 2024, 383, 326– 330,  DOI: 10.1126/science.adk6628
    Google Scholar
    There is no corresponding record for this reference.
  16. 16
    Jin, R.; Zeng, C.; Zhou, M.; Chen, Y. Atomically Precise Colloidal Metal Nanoclusters and Nanoparticles: Fundamentals and Opportunities. Chem. Rev. 2016, 116, 10346– 10413,  DOI: 10.1021/acs.chemrev.5b00703
    Google Scholar
    16
    Atomically Precise Colloidal Metal Nanoclusters and Nanoparticles: Fundamentals and Opportunities
    Jin, Rongchao; Zeng, Chenjie; Zhou, Meng; Chen, Yuxiang
    Chemical Reviews (Washington, DC, United States) (2016), 116 (18), 10346-10413CODEN: CHREAY; ISSN:0009-2665. (American Chemical Society)
    A review. Colloidal nanoparticles are being intensely pursued in current nanoscience research. Nanochemists are often frustrated by the known fact that no two nanoparticles are the same, which precludes the deep understanding of many fundamental properties of colloidal nanoparticles in which the total structures (core plus surface) must be known. Therefore, controlling nanoparticles with at. precision and solving their total structures have long been major dreams for nanochemists. Recently, these goals are partially fulfilled in the case of gold nanoparticles, at least in the ultrasmall size regime (1-3 nm in diam., often called nanoclusters). This review summarizes the major progress in the field, including the principles that permit atomically precise synthesis, new types of at. structures, and unique phys. and chem. properties of atomically precise nanoparticles, as well as exciting opportunities for nanochemists to understand very fundamental science of colloidal nanoparticles (such as the stability, metal-ligand interfacial bonding, ligand assembly on particle surfaces, aesthetic structural patterns, periodicities, and emergence of the metallic state) and to develop a range of potential applications such as in catalysis, biomedicine, sensing, imaging, optics, and energy conversion. Although most of the research activity currently focuses on thiolate-protected gold nanoclusters, important progress also was achieved in other ligand-protected gold, silver, and bimetal (or alloy) nanoclusters. All of these types of unique nanoparticles will bring unprecedented opportunities, not only in understanding the fundamental questions of nanoparticles but also in opening up new horizons for scientific studies of nanoparticles.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhsVeksLnJ&md5=aa1208c72c4e8de1be9a4a906a9bc6c9
  17. 17
    Xia, N.; Wu, Z. Controlling Ultrasmall Gold Nanoparticles with Atomic Precision. Chem. Sci. 2021, 12, 2368– 2380,  DOI: 10.1039/D0SC05363E
    Google Scholar
    17
    Controlling ultrasmall gold nanoparticles with atomic precision
    Xia, Nan; Wu, Zhikun
    Chemical Science (2021), 12 (7), 2368-2380CODEN: CSHCCN; ISSN:2041-6520. (Royal Society of Chemistry)
    A review. Gold nanoparticles are probably the nanoparticles that have been best studied for the longest time due to their stability, physicochem. properties and applications. Controlling gold nanoparticles with at. precision is of significance for subsequent research on their structures, properties and applications, which is a dream that has been pursued for many years since ruby gold was first obtained by Faraday in 1857. Fortunately, this dream has recently been partially realized for some ultrasmall gold nanoparticles (nanoclusters). However, rationally designing and synthesizing gold nanoparticles with at. precision are still distant goals, and this challenge might rely primarily on rich atomically precise gold nanoparticle libraries and the in-depth understanding of metal nanoparticle chem. Herein, we review general synthesis strategies and some facile synthesis methods, with an emphasis on the controlling parameters detd. from well-documented results, which might have important implications for future nanoparticle synthesis with at. precision and facilitate related research and applications.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXis1Kku7%252FK&md5=c736748e4abdc913e91f79416a471caa
  18. 18
    Luo, Z.; Yuan, X.; Yu, Y.; Zhang, Q.; Leong, D. T.; Lee, J. Y.; Xie, J. From Aggregation-Induced Emission of Au(I)-Thiolate Complexes to Ultrabright Au(0)@Au(I)-Thiolate Core-Shell Nanoclusters. J. Am. Chem. Soc. 2012, 134, 16662– 16670,  DOI: 10.1021/ja306199p
    Google Scholar
    18
    From Aggregation-Induced Emission of Au(I)-Thiolate Complexes to Ultrabright Au(0)@Au(I)-Thiolate Core-Shell Nanoclusters
    Luo, Zhentao; Yuan, Xun; Yu, Yue; Zhang, Qingbo; Leong, David Tai; Lee, Jim Yang; Xie, Jianping
    Journal of the American Chemical Society (2012), 134 (40), 16662-16670CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
    A fundamental understanding of the luminescence of Au-thiolate nanoclusters (NCs), such as the origin of emission and the size effect in luminescence, is pivotal to the development of efficient synthesis routes for highly luminescent Au NCs. This paper reports an interesting finding of Au(I)-thiolate complexes: strong luminescence emission by the mechanism of aggregation-induced emission (AIE). The AIE property of the complexes was then used to develop a simple 1-pot synthesis of highly luminescent Au-thiolate NCs with a quantum yield of ∼15%. Key strategy was to induce the controlled aggregation of Au(I)-thiolate complexes on in situ generated Au(0) cores to form Au(0)@Au(I)-thiolate core-shell NCs where strong luminescence was generated by the AIE of Au(I)-thiolate complexes on the NC surface. The authors were able to extend the synthetic strategy to other thiolate ligands with added functionalities (as custom-designed peptides). The discovery (e.g., identifying the source of emission and the size effect in luminescence) and the synthesis protocols in this study can contribute significantly to better understanding of these new luminescence probes and the development of new synthetic routes.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhtl2mu7nO&md5=3ffed2ce6a4724ccddcb4187a8dcc8cc
  19. 19
    Liu, Z.; Luo, L.; Jin, R. Visible to NIR-II Photoluminescence of Atomically Precise Gold Nanoclusters. Adv. Mater. 2024, 36, e2309073  DOI: 10.1002/adma.202309073
    Google Scholar
    There is no corresponding record for this reference.
  20. 20
    Si, W.-D.; Zhang, C.; Zhou, M.; Wang, Z.; Feng, L.; Tung, C.-H.; Sun, D. Arylgold nanoclusters: Phenyl-Stabilized Au44 with Thermal-Controlled NIR Single/Dual-Channel Phosphorescence. Sci. Adv. 2024, 10, eadm6928  DOI: 10.1126/sciadv.adm6928
    Google Scholar
    There is no corresponding record for this reference.
  21. 21
    Hirai, H.; Takano, S.; Nakashima, T.; Iwasa, T.; Taketsugu, T.; Tsukuda, T. Doping-Mediated Energy-Level Engineering of M@Au12 Superatoms (M = Pd, Pt, Rh, Ir) for Efficient Photoluminescence and Photocatalysis. Angew. Chem., Int. Ed. 2022, 61, e202207290  DOI: 10.1002/anie.202207290
    Google Scholar
    21
    Doping-Mediated Energy-Level Engineering of M@Au12 Superatoms (M=Pd, Pt, Rh, Ir) for Efficient Photoluminescence and Photocatalysis
    Hirai, Haru; Takano, Shinjiro; Nakashima, Takuya; Iwasa, Takeshi; Taketsugu, Tetsuya; Tsukuda, Tatsuya
    Angewandte Chemie, International Edition (2022), 61 (36), e202207290CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
    We synthesized a series of MAu12(dppe)5Cl2 (MAu12; M=Au, Pd, Pt, Rh, or Ir; dppe=1,2-bis(diphenylphosphino)ethane), which have icosahedral M@Au12 superat. cores, and systematically investigated their electronic structures, photoluminescence (PL) and photocatalytic properties. The energy gap between the HOMO (HOMO) and the LUMO (LUMO) was expanded when doping an M element positioned at the lower left of the periodic table. The PL quantum yield was enhanced with an increase in the HOMO-LUMO gap and reached 0.46-0.67 for MAu12 (M=Pt, Rh, or Ir) under deaerated conditions. The bright PLs from MAu12 (M=Pt, Rh, or Ir) were assigned to phosphorescence based on quenching by O2. MAu12 (M=Pt, Rh, or Ir) acted as a more efficient and stable photocatalyst than Au13 for intramol. [2+2] cycloaddn. of bisenone via the oxidative quenching cycle. This study provides rational guides for designing photoluminescent and photocatalytic gold superatoms by the doping of heterometal elements.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38Xhs1ClsbfK&md5=08cbb15c9854b3d47cd72bac6134e756
  22. 22
    Yang, G.; Pan, X.; Feng, W.; Yao, Q.; Jiang, F.; Du, F.; Zhou, X.; Xie, J.; Yuan, X. Engineering Au44 Nanoclusters for NIR-II Luminescence Imaging-Guided Photoactivatable Cancer Immunotherapy. ACS Nano 2023, 17, 15605– 15614,  DOI: 10.1021/acsnano.3c02370
    Google Scholar
    22
    Engineering Au44 Nanoclusters for NIR-II Luminescence Imaging-Guided Photoactivatable Cancer Immunotherapy
    Yang, Ge; Pan, Xinxin; Feng, Wenbi; Yao, Qiaofeng; Jiang, Fuyi; Du, Fanglin; Zhou, Xianfeng; Xie, Jianping; Yuan, Xun
    ACS Nano (2023), 17 (16), 15605-15614CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
    Immunotherapy is an advanced therapeutic strategy of cancer treatment but suffers from the issues of off-target adverse effects, lack of real-time monitoring techniques, and unsustainable response. Herein, an ultrasmall Au nanocluster (NC)-based theranostic probe is designed for second near-IR window (NIR-II) photoluminescence (PL) imaging-guided phototherapies and photoactivatable cancer immunotherapy. The probe (Au44MBA26-NLG for short) is composed of atomically precise and NIR-II emitting Au44MBA26 NCs (here MBA denotes water-sol. 4-mercaptobenzoic acid) conjugated with immune checkpoint inhibitor 1-cyclohexyl-2-(5H-imidazo[5,1-a]isoindol-5-yl)ethanol (NLG919) via a singlet oxygen (1O2)-cleavable linker. Upon NIR photoirradn., the Au44MBA26-NLG not only enables NIR-II PL imaging of tumors in deep tissues for guiding tumor therapy but also allows the leverage of photothermal property for cancer photothermal therapy (PTT) and the photogenerated 1O2 for photodynamic therapy (PDT) and releasing NLG919 for cancer immunotherapy. Such a multiple effect modulated by Au44MBA26-NLG prompts the proliferation and activation of effector T cells, upshifts systemic antitumor T-lymphocyte (T cell) immunity, and finally suppresses the growth of both primary and distant tumors in living mice. Overall, this study may provide a promising theranostic nanoplatform toward NIR-II PL imaging-guided phototherapies and photoactivatable cancer immunotherapy.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXhsFCrtbzP&md5=084a7ae2b85e03a54f04075cd6258bbc
  23. 23
    Weerawardene, K. L.; Aikens, C. M. Theoretical Insights into the Origin of Photoluminescence of Au25(SR)18– Nanoparticles. J. Am. Chem. Soc. 2016, 138, 11202– 11210,  DOI: 10.1021/jacs.6b05293
    Google Scholar
    23
    Theoretical Insights into the Origin of Photoluminescence of Au25(SR)18- Nanoparticles
    Weerawardene, K. L. Dimuthu M.; Aikens, Christine M.
    Journal of the American Chemical Society (2016), 138 (35), 11202-11210CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
    Understanding fundamental behavior of luminescent nanomaterials upon photoexcitation is necessary to expand photocatalytic and biol. imaging applications. Despite the significant amt. of exptl. work into the luminescence of Au25(SR)18- clusters, the origin of photoluminescence in these clusters still remains unclear. The geometric and electronic structural changes of the Au25(SR)18- (R = H, CH3, CH2CH3, CH2CH2CH3) nanoclusters upon photoexcitation are discussed using time-dependent d. functional theory (TD-DFT) methods. Geometric relaxations in the optimized excited states of up to 0.33 Å impart remarkable effects on the energy levels of the frontier orbitals of Au25(SR)18- nanoclusters. This gives rise to a Stokes shift of 0.49 eV for Au25(SH)18- in agreement with expts. Even larger Stokes shifts are predicted for longer ligands. Vibrational frequencies in the 75-80 cm-1 range are calcd. for the nuclear motion involved in the excited-state nuclear relaxation; this value is in excellent agreement with vibrational beating obsd. in time-resolved spectroscopy expts. Several excited states around 0.8, 1.15, and 1.25 eV are calcd. for the Au25(SH)18- nanocluster. Considering the typical underestimation of DFT excitation energies, these states are likely responsible for the emission obsd. exptl. in the 1.15-1.55 eV range. All excited states arise from core-based orbitals; charge-transfer states or other semi-ring or ligand-based states are not implicated.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhtleiurfK&md5=70c4d2ccd967529df54ab7d5f1fe3ca7
  24. 24
    Liu, Z.; Zhou, M.; Luo, L.; Wang, Y.; Kahng, E.; Jin, R. Elucidating the Near-Infrared Photoluminescence Mechanism of Homometal and Doped M25(SR)18 Nanoclusters. J. Am. Chem. Soc. 2023, 145, 19969– 19981,  DOI: 10.1021/jacs.3c06543
    Google Scholar
    24
    Elucidating the Near-Infrared Photoluminescence Mechanism of Homometal and Doped M25(SR)18 Nanoclusters
    Liu, Zhongyu; Zhou, Meng; Luo, Lianshun; Wang, Yitong; Kahng, Ellen; Jin, Rongchao
    Journal of the American Chemical Society (2023), 145 (36), 19969-19981CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
    More than a decade of research on the photoluminescence (PL) of classic Au25(SR)18 and its doped nanoclusters (NCs) still leaves many fundamental questions unanswered due to the complex electron dynamics. Here, the authors revisit the homogold Au25 (ligands omitted hereafter) and doped NCs, as well as the Ag25 and doped ones, for a comparative study to disentangle the influencing factors and elucidate the PL mechanism. The strong electron-vibration coupling in Au25 leads to weak PL in the near-IR region (~ 1000 nm, quantum yield QY = 1% in soln. at room temp.). Heteroatom doping of Au25 with a single Cd or Hg atom strengthens the coupling of the exciton with staple vibrations but reduces the coupling with the core breathing and quadrupolar modes. The QYs of the three MAu24 NCs (M = Hg, Au, and Cd) follow a linear relation with their PL lifetimes, suggesting a mechanism of suppressed nonradiative decay in PL enhancement. In contrast, the weaker electron-vibration coupling in Ag25 leads to higher PL (QY = 3.5%), and single Au atom doping further leads to a 5x enhancement of the radiative rate and a suppression of nonradiative decay rate (i.e., twice the PL lifetime of Ag25) in AuAg24 (hence, QY 35%), but doping more Au atoms results in Au distribution to staple motifs and thus triggering of strong electron-vibration coupling as in the MAu24 NCs, hence, counteracting the radiative enhancement effect and giving rise to only 5% QY for AuxAg25-x (x = 3-10). The obtained insights will provide guidance for the design of metal NCs with high PL for lighting, sensing, and optoelectronic applications.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXhslOlsLvL&md5=b7ae109a5a40639e5ae79be065f692e9
  25. 25
    Pyo, K.; Thanthirige, V. D.; Kwak, K.; Pandurangan, P.; Ramakrishna, G.; Lee, D. Ultrabright Luminescence from Gold Nanoclusters: Rigidifying the Au(I)-Thiolate Shell. J. Am. Chem. Soc. 2015, 137, 8244– 8250,  DOI: 10.1021/jacs.5b04210
    Google Scholar
    25
    Ultrabright Luminescence from Gold Nanoclusters: Rigidifying the Au(I)-Thiolate Shell
    Pyo, Kyunglim; Thanthirige, Viraj Dhanushka; Kwak, Kyuju; Pandurangan, Prabhu; Ramakrishna, Guda; Lee, Dongil
    Journal of the American Chemical Society (2015), 137 (25), 8244-8250CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
    Luminescent nanomaterials have captured the imagination of scientists for a long time and offer great promise for applications in org./inorg. light-emitting displays, optoelectronics, optical sensors, biomedical imaging, and diagnostics. Atomically precise gold clusters with well-defined core-shell structures present bright prospects to achieve high photoluminescence efficiencies. In this study, gold clusters with a luminescence quantum yield greater than 60% were synthesized based on the Au22(SG)18 cluster, where SG is glutathione, by rigidifying its gold shell with tetraoctylammonium (TOA) cations. Time-resolved and temp.-dependent optical measurements on Au22(SG)18 have shown the presence of high quantum yield visible luminescence below freezing, indicating that shell rigidity enhances the luminescence quantum efficiency. To achieve high rigidity of the gold shell, Au22(SG)18 was bound to bulky TOA that resulted in greater than 60% quantum yield luminescence at room temp. Optical measurements have confirmed that the rigidity of gold shell was responsible for the luminescence enhancement. This work presents an effective strategy to enhance the photoluminescence efficiencies of gold clusters by rigidifying the Au(I)-thiolate shell.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhtVagtbjO&md5=3c27c44f816be68faa74df06229ed369
  26. 26
    Ma, X. H.; Li, J.; Luo, P.; Hu, J. H.; Han, Z.; Dong, X. Y.; Xie, G.; Zang, S. Q. Carbene-Stabilized Enantiopure Heterometallic Clusters Featuring EQE of 20.8% in Circularly-Polarized OLED. Nat. Commun. 2023, 14, 4121,  DOI: 10.1038/s41467-023-39802-w
    Google Scholar
    26
    Carbene-stabilized enantiopure heterometallic clusters featuring EQE of 20.8% in circularly-polarized OLED
    Ma, Xiao-Hong; Li, Jing; Luo, Peng; Hu, Jia-Hua; Han, Zhen; Dong, Xi-Yan; Xie, Guohua; Zang, Shuang-Quan
    Nature Communications (2023), 14 (1), 4121CODEN: NCAOBW; ISSN:2041-1723. (Nature Portfolio)
    Bright and efficient chiral coinage metal clusters show promise for use in emerging circularly polarized light-emitting materials and diodes. To date, highly efficient circularly polarized org. light-emitting diodes (CP-OLEDs) with enantiopure metal clusters have not been reported. Herein, through rational design of a multidentate chiral N-heterocyclic carbene (NHC) ligand and a modular building strategy, we synthesize a series of enantiopure Au(I)-Cu(I) clusters with exceptional stability. Modulation of the ligands stabilize the chiral excited states of clusters to allow thermally activated delayed fluorescence, resulting in the highest orange-red photoluminescence quantum yields over 93.0% in the solid state, which is accompanied by circularly polarized luminescence. Based on the soln. process, a prototypical orange-red CP-OLED with a considerably high external quantum efficiency of 20.8% is prepd. These results demonstrate the extensive designability of chiral NHC ligands to stabilize polymetallic clusters for high performance in chiroptical applications.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXhsVKms7nN&md5=68051f6d4f9352283ce7c26e3041b82e
  27. 27
    Zhong, Y.; Zhang, J.; Li, T.; Xu, W.; Yao, Q.; Lu, M.; Bai, X.; Wu, Z.; Xie, J.; Zhang, Y. Suppression of Kernel Vibrations by Layer-by-Layer Ligand Engineering Boosts Photoluminescence Efficiency of Gold Nanoclusters. Nat. Commun. 2023, 14, 658,  DOI: 10.1038/s41467-023-36387-2
    Google Scholar
    27
    Suppression of kernel vibrations by layer-by-layer ligand engineering boosts photoluminescence efficiency of gold nanoclusters
    Zhong, Yuan; Zhang, Jiangwei; Li, Tingting; Xu, Wenwu; Yao, Qiaofeng; Lu, Min; Bai, Xue; Wu, Zhennan; Xie, Jianping; Zhang, Yu
    Nature Communications (2023), 14 (1), 658CODEN: NCAOBW; ISSN:2041-1723. (Nature Portfolio)
    The restriction of structural vibration has assumed great importance in attaining bright emission of luminescent metal nanoclusters (NCs), where tremendous efforts are devoted to manipulating the surface landscape yet remain challenges for modulation of the structural vibration of the metal kernel. Here, we report efficient suppression of kernel vibration achieving enhancement in emission intensity, by rigidifying the surface of metal NCs and propagating as-developed strains into the metal core. Specifically, a layer-by-layer triple-ligands surface engineering is deployed to allow the soln.-phase Au NCs with strong metal core-dictated fluorescence, up to the high abs. quantum yields of 90.3 ± 3.5%. The as-rigidified surface imposed by synergistic supramol. interactions greatly influences the low-frequency acoustic vibration of the metal kernel, resulting in a subtle change in vibration frequency but a redn. in amplitude of oscillation. This scenario therewith impedes the non-radiative relaxation of electron dynamics, rendering the Au NCs with strong emission. The presented study exemplifies the linkage between surface chem. and core-state emission of metal NCs, and proposes a strategy for brighter emitting metal NCs by regulating their interior metal core-involved motion.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXjtVWqtbY%253D&md5=d68cb1b147309c3b18630de34df5056e
  28. 28
    Dong, J.; Gan, Z.; Gu, W.; You, Q.; Zhao, Y.; Zha, J.; Li, J.; Deng, H.; Yan, N.; Wu, Z. Synthesizing Photoluminescent Au28(SCH2Ph-tBu)22 Nanoclusters with Structural Features by Using a Combined Method. Angew. Chem., Int. Ed. 2021, 60, 17932– 17936,  DOI: 10.1002/anie.202105530
    Google Scholar
    28
    Synthesizing Photoluminescent Au28(SCH2Ph-tBu)22 Nanoclusters with Structural Features by Using A Combined Method
    Dong, Jingwu; Gan, Zibao; Gu, Wanmiao; You, Qing; Zhao, Yan; Zha, Jun; Li, Jin; Deng, Haiteng; Yan, Nan; Wu, Zhikun
    Angewandte Chemie, International Edition (2021), 60 (33), 17932-17936CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
    We present a method for atomically precise nanocluster synthesis. As an illustration, we introduced the reducing-ligand induction combined method and synthesized a novel nanocluster, which was detd. to be Au28(SCH2Ph-tBu)22 with the same no. of gold atoms as existing Au28(SR)20 nanoclusters but different ligands (hetero-compn.-homo-size). Compared with the latter, the former has distinct properties and structures. In particular, a novel kernel evolution pattern is reported, i.e., the quasi-linear growth of Au4-tetrahedron by sharing one vertex and structural features, including a tritetrahedron kernel with two bridging thiolates and two Au6(SCH2Ph-tBu)6 hexamer chair-like rings on the kernel surface were also first reported, which endow Au28(SCH2Ph-tBu)22 with the best photoluminescence quantum yield among hydrophobic thiolated gold nanoclusters so far, probably due to the enhanced charge transfer from the bi-ring to the kernel via Au-Au bonds.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXhs1ems7zJ&md5=ac18a8c8c882429b97af4def1f7823b3
  29. 29
    Peng, Q. C.; Si, Y. B.; Wang, Z. Y.; Dai, S. H.; Chen, Q. S.; Li, K.; Zang, S. Q. Thermally Activated Delayed Fluorescence Coinage Metal Cluster Scintillator. ACS Cent. Sci. 2023, 9, 1419– 1426,  DOI: 10.1021/acscentsci.3c00563
    Google Scholar
    29
    Thermally Activated Delayed Fluorescence Coinage Metal Cluster Scintillator
    Peng, Qiu-Chen; Si, Yu-Bing; Wang, Zhao-Yang; Dai, Shu-Heng; Chen, Qiu-Shui; Li, Kai; Zang, Shuang-Quan
    ACS Central Science (2023), 9 (7), 1419-1426CODEN: ACSCII; ISSN:2374-7951. (American Chemical Society)
    X-ray scintillators are widely used in medical imaging, industrial flaw detection, security inspection, and space exploration. However, traditional com. scintillators are usually assocd. with a high use cost because of their substantial toxicity and easy deliquescence. An atomically precise Au-Cu cluster scintillator (1) with a thermally activated delayed fluorescence (TADF) property was facilely synthesized, which is environmentally friendly and highly stable to H2O and O. The TADF property of 1 endows it with an ultrahigh exciton use rate. Combined with the effective absorption of x-ray caused by the heavy-atom effect and a limited nonradiative transition caused by close packing in the crystal state, 1 exhibits an excellent radioluminescence property. 1 has good processability for fabricating a large, flexible thin-film device (10 cm x 10 cm) for high-resoln. x-ray imaging, which can reach 40 μm (12.5 LP mm-1). The properties mentioned earlier make the coinage metal cluster promising for use as a substitute for traditional com. scintillators.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXht1Oms7rJ&md5=3aafaa552d3e2142d1e941e064ad36b9
  30. 30
    Li, Q.; Zhou, M.; So, W. Y.; Huang, J.; Li, M.; Kauffman, D. R.; Cotlet, M.; Higaki, T.; Peteanu, L. A.; Shao, Z.; Jin, R. A Mono-cuboctahedral Series of Gold Nanoclusters: Photoluminescence Origin, Large Enhancement, Wide Tunability, and Structure-Property Correlation. J. Am. Chem. Soc. 2019, 141, 5314– 5325,  DOI: 10.1021/jacs.8b13558
    Google Scholar
    30
    A Mono-cuboctahedral Series of Gold Nanoclusters: Photoluminescence Origin, Large Enhancement, Wide Tunability, and Structure-Property Correlation
    Li, Qi; Zhou, Meng; So, Woong Young; Huang, Jingchun; Li, Mingxing; Kauffman, Douglas R.; Cotlet, Mircea; Higaki, Tatsuya; Peteanu, Linda A.; Shao, Zhengzhong; Jin, Rongchao
    Journal of the American Chemical Society (2019), 141 (13), 5314-5325CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
    The origin of the near-IR photoluminescence (PL) from thiolate-protected gold nanoclusters (Au NCs, <2 nm) has long been controversial, and the exact mechanism for the enhancement of quantum yield (QY) in many works remains elusive. Meanwhile, based upon the sole steady-state PL anal., it is still a major challenge for researchers to map out a definitive relationship between the at. structure and the PL property and understand how the Au(0) kernel and Au(I)-S surface contribute to the PL of Au NCs. Herein, we provide a paradigm study to address the above crit. issues. By using a correlated series of "mono-cuboctahedral kernel" Au NCs and combined analyses of steady-state, temp.-dependence, femtosecond transient absorption, and Stark spectroscopy measurements, we have explicitly mapped out a kernel-origin mechanism and clearly elucidate the surface-structure effect, which establishes a definitive at.-level structure-emission relationship. A ∼100-fold enhancement of QY is realized via suppression of two effects: (i) the ultrafast kernel relaxation and (ii) the surface vibrations. The new insights into the PL origin, QY enhancement, wavelength tunability, and structure-property relationship constitute a major step toward the fundamental understanding and structural-tailoring-based modulation and enhancement of PL from Au NCs.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXkvVSls70%253D&md5=19c3d52052299e37ac2c51eae161fa10
  31. 31
    Zhou, M.; Du, X.; Wang, H.; Jin, R. The Critical Number of Gold Atoms for a Metallic State Nanocluster: Resolving a Decades-Long Question. ACS Nano 2021, 15, 13980– 13992,  DOI: 10.1021/acsnano.1c04705
    Google Scholar
    31
    The Critical Number of Gold Atoms for a Metallic State Nanocluster: Resolving a Decades-Long Question
    Zhou, Meng; Du, Xiangsha; Wang, He; Jin, Rongchao
    ACS Nano (2021), 15 (9), 13980-13992CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
    A review. Probing the transition from a metallic state to a mol. state in gold nanoparticles is fundamentally important for understanding the origin of surface plasmon resonance and the nature of the metallic bond. Atomically precise gold nanoclusters are desired for probing such a transition based upon a series of precise sizes with X-ray structures. While the definition of the metallic state in nanoclusters is simple, i.e., when the HOMO-LUMO gap (Eg) becomes negligibly small (Eg < kBT, where kB is the Boltzmann const. and T the temp.), the exptl. detn. of ultrasmall Eg (e.g., of kBT level) is difficult, and the thermal excitation of valence electrons apparently comes into play in ultrasmall Eg nanoclusters. Although a sharp transition from nonmetallic Au246(SR)80 to metallic Au279(SR)84 (SR: thiolate) has been obsd., there is still uncertainty about the transition region. Here, we summarize several criteria on detg. the metallic state vs. the mol. (or nonmetallic) state in gold nanoclusters, including (1) Eg detd. by optical and electrochem. methods, (2) steady-state absorption spectra, (3) cryogenic optical spectra, (4) transient absorption spectra, (5) excited-state lifetime and power dependence, and (6) coherent oscillations in ultrafast electron dynamics. We emphasize that multiple analyses should be performed and cross-checked in practice because no single criterion is definitive. We also review the photophysics of several gold nanoclusters with nascent surface plasmon resonance. These criteria are expected to deepen the understanding of the metallic to mol. state transition of gold and other metal nanoclusters and also promote the design of functional nanomaterials and their applications.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXhvFCqsLzM&md5=24be4adf9fc8778b393203f40096ae8b
  32. 32
    Kwak, K.; Thanthirige, V. D.; Pyo, K.; Lee, D.; Ramakrishna, G. Energy Gap Law for Exciton Dynamics in Gold Cluster Molecules. J. Phys. Chem. Lett. 2017, 8, 4898– 4905,  DOI: 10.1021/acs.jpclett.7b01892
    Google Scholar
    32
    Energy Gap Law for Exciton Dynamics in Gold Cluster Molecules
    Kwak, Kyuju; Thanthirige, Viraj Dhanushka; Pyo, Kyunglim; Lee, Dongil; Ramakrishna, Guda
    Journal of Physical Chemistry Letters (2017), 8 (19), 4898-4905CODEN: JPCLCD; ISSN:1948-7185. (American Chemical Society)
    The energy gap law relates the nonradiative decay rate to the energy gap sepg. the ground and excited states. Here the authors report that the energy gap law can be applied to exciton dynamics in Au cluster mols. Size-dependent electrochem. and optical properties were studied for n-hexanethiolate-protected Au clusters ranging from Au25 to Au333. Voltammetric studies reveal that the HOMO-LUMO (HOMO-LUMO) gaps of these clusters decrease with increasing cluster size. Combined femtosecond and nanosecond time-resolved transient absorption measurements show that the exciton lifetimes decrease with increasing cluster size. Comparison of the size-dependent exciton lifetimes with the HOMO-LUMO gaps shows that they are linearly correlated, demonstrating the energy gap law for excitons in these Au cluster mols.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhsFens7bJ&md5=388b7ce301f64fd437fc9cd9415756cc
  33. 33
    Li, Q.; Zhou, D.; Chai, J.; So, W. Y.; Cai, T.; Li, M.; Peteanu, L. A.; Chen, O.; Cotlet, M.; Wendy Gu, X.; Zhu, H.; Jin, R. Structural Distortion and Electron Redistribution in Dual-Emitting Gold Nanoclusters. Nat. Commun. 2020, 11, 2897,  DOI: 10.1038/s41467-020-16686-8
    Google Scholar
    33
    Structural distortion and electron redistribution in dual-emitting gold nanoclusters
    Li, Qi; Zhou, Dongming; Chai, Jinsong; So, Woong Young; Cai, Tong; Li, Mingxing; Peteanu, Linda A.; Chen, Ou; Cotlet, Mircea; Wendy Gu, X.; Zhu, Haiming; Jin, Rongchao
    Nature Communications (2020), 11 (1), 2897CODEN: NCAOBW; ISSN:2041-1723. (Nature Research)
    Abstr.: Deciphering the complicated excited-state process is crit. for the development of luminescent materials with controllable emissions in different applications. Here we report the emergence of a photo-induced structural distortion accompanied by an electron redistribution in a series of gold nanoclusters. Such unexpected slow process of excited-state transformation results in near-IR dual emission with extended photoluminescent lifetime. We demonstrate that this dual emission exhibits highly sensitive and ratiometric response to solvent polarity, viscosity, temp. and pressure. Thus, a versatile luminescent nano-sensor for multiple environmental parameters is developed based on this strategy. Furthermore, we fully unravel the at.-scale structural origin of this unexpected excited-state transformation, and demonstrate control over the transition dynamics by tailoring the bi-tetrahedral core structures of gold nanoclusters. Overall, this work provides a substantial advance in the excited-state phys. chem. of luminescent nanoclusters and a general strategy for the rational design of next-generation nano-probes, sensors and switches.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhtFGhsrnM&md5=28a6701e269aa913c950bff95583ae6d
  34. 34
    Fan, W.; Yang, Y.; You, Q.; Li, J.; Deng, H.; Yan, N.; Wu, Z. Size- and Shape-Dependent Photoexcitation Electron Transfer in Metal Nanoclusters. J. Phys. Chem. C 2023, 127, 816– 823,  DOI: 10.1021/acs.jpcc.2c07678
    Google Scholar
    There is no corresponding record for this reference.
  35. 35
    Wang, Y.; Liu, Z.; Mazumder, A.; Gianopoulos, C. G.; Kirschbaum, K.; Peteanu, L. A.; Jin, R. Tailoring Carbon Tails of Ligands on Au52(SR)32 Nanoclusters Enhances the Near-Infrared Photoluminescence Quantum Yield from 3.8 to 18.3%. J. Am. Chem. Soc. 2023, 145, 26328– 26338,  DOI: 10.1021/jacs.3c09846
    Google Scholar
    There is no corresponding record for this reference.
  36. 36
    Liu, Z.; Luo, L.; Kong, J.; Kahng, E.; Zhou, M.; Jin, R. Bright Near-Infrared Emission from the Au39(SR)29 Nanocluster. Nanoscale 2024, 16, 7419– 7426,  DOI: 10.1039/D4NR00677A
    Google Scholar
    There is no corresponding record for this reference.
  37. 37
    Pniakowska, A.; Kumaranchira Ramankutty, K.; Obstarczyk, P.; Peric Bakulic, M.; Sanader Marsic, Z.; Bonacic-Koutecky, V.; Burgi, T.; Olesiak-Banska, J. Gold-Doping Effect on Two-Photon Absorption and Luminescence of Atomically Precise Silver Ligated Nanoclusters. Angew. Chem., Int. Ed. 2022, 61, e202209645  DOI: 10.1002/anie.202209645
    Google Scholar
    37
    Gold-Doping Effect on Two-Photon Absorption and Luminescence of Atomically Precise Silver Ligated Nanoclusters
    Pniakowska, Anna; Kumaranchira Ramankutty, Krishnadas; Obstarczyk, Patryk; Peric Bakulic, Martina; Sanader Marsic, Zeljka; Bonacic-Koutecky, Vlasta; Buergi, Thomas; Olesiak-Banska, Joanna
    Angewandte Chemie, International Edition (2022), 61 (43), e202209645CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
    Noble metal nanoclusters allow for the atomically-precise control of their compn. However, to create nanoclusters with pre-defined optical properties, comprehensive description of their structure-property relation is required. Here, we report the gold atom doping impact on one-photon and two-photon absorption (TPA) and luminescence properties of ligated silver nanoclusters via combined exptl. studies and time-dependent d. functional theory simulations (TD-DFT). We synthesized a series of Ag25-xAux(DMBT)18 nanoclusters where x=0, 1 and 5-10. For Ag24Au1(DMBT)18 we demonstrate that the presence of the central Au dopant strongly influences linear and non-linear optical properties, increasing photoluminescence quantum yield and two-photon brightness, with respect to undoped silver nanoclusters. With improved TPA and luminescence, atomically-precise AuAg alloys presented in our work can serve as robust luminescent probes e.g. for bioimaging in the second biol. window.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38Xitl2ntLnP&md5=0b3f1660f9f0237a5540bbaa7b256a8d
  38. 38
    Li, Q.; Zeman, C. J. t.; Schatz, G. C.; Gu, X. W. Source of Bright Near-Infrared Luminescence in Gold Nanoclusters. ACS Nano 2021, 15, 16095– 16105,  DOI: 10.1021/acsnano.1c04759
    Google Scholar
    38
    Source of Bright Near-Infrared Luminescence in Gold Nanoclusters
    Li, Qi; Zeman, Charles J.; Schatz, George C.; Gu, X. Wendy
    ACS Nano (2021), 15 (10), 16095-16105CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
    Gold nanoclusters with near-IR (NIR) photoluminescence (PL) have great potential as sensing and imaging materials in biomedical and bioimaging applications. In this work, Au21(S-Adm)15 and Au38S2(S-Adm)20 are used to unravel the underlying mechanisms for the improved quantum yields (QY), large Stokes shifts, and long PL lifetimes in gold nanoclusters. Both nanoclusters show decent PL QY. In particular, the Au38S2(S-Adm)20 nanocluster shows a bright NIR PL at 900 nm with QY up to 15% in normal solvents (such as toluene) at ambient conditions. The relatively lower QY for Au21(S-Adm)15 (4%) compared to that of Au38S2(S-Adm)20 is attributed to the lowest-lying excited state being symmetry-disallowed, as evidenced by the pressure-dependent antispectral shift of the absorption spectra compared to PL, yet Au21(S-Adm)15 maintains some emissive properties due to a nearby symmetry-allowed excited state. Furthermore, our results show that suppression of nonradiative decay due to the surface "lock rings", which encircle the Au kernel and the surface "lock atoms" which bridge the fundamental Au kernel units (e.g., tetrahedra, icosahedra, etc.), is the key to obtaining high QYs in gold nanoclusters. The complicated excited-state processes and the small absorption coeff. of the band-edge transition lead to the large Stokes shifts and the long PL lifetimes that are widely obsd. in gold nanoclusters.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXitFOhtL3K&md5=91cca9762c861d40ff362fa9a4441a06
  39. 39
    Narouz, M. R.; Takano, S.; Lummis, P. A.; Levchenko, T. I.; Nazemi, A.; Kaappa, S.; Malola, S.; Yousefalizadeh, G.; Calhoun, L. A.; Stamplecoskie, K. G.; Hakkinen, H.; Tsukuda, T.; Crudden, C. M. Robust, Highly Luminescent Au13 Superatoms Protected by N-Heterocyclic Carbenes. J. Am. Chem. Soc. 2019, 141, 14997– 15002,  DOI: 10.1021/jacs.9b07854
    Google Scholar
    39
    Robust, Highly Luminescent Au13 Superatoms Protected by N-Heterocyclic Carbenes
    Narouz, Mina R.; Takano, Shinjiro; Lummis, Paul A.; Levchenko, Tetyana I.; Nazemi, Ali; Kaappa, Sami; Malola, Sami; Yousefalizadeh, Goonay; Calhoun, Larry A.; Stamplecoskie, Kevin G.; Hakkinen, Hannu; Tsukuda, Tatsuya; Crudden, Cathleen M.
    Journal of the American Chemical Society (2019), 141 (38), 14997-15002CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
    Au superatom nanoclusters stabilized entirely by N-heterocyclic carbenes (NHCs) and halides are reported. The redn. of well-defined NHC-Au-Cl complexes produces clusters comprised of an icosahedral Au13 core surrounded by a sym. arrangement of nine NHCs and three chlorides. X-ray crystallog. shows that the clusters were characterized by multiple CH-π and π-π interactions, which rigidify the ligand and likely contribute to the exceptionally high photoluminescent quantum yields obsd., up to 16.0%, which is significantly greater than that of the most luminescent ligand-protected Au13 superatom cluster. D. functional theory anal. suggests that clusters are 8-electron superatoms with a wide HOMO-LUMO energy gap of 2 eV. Consistent with this, the clusters have high stability relative to phosphine stabilized clusters.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhslegt7vP&md5=97e2ef250fb664f184d48b6a1963e718
  40. 40
    She, J.; Pei, W.; Zhou, S.; Zhao, J. Enhanced Fluorescence with Tunable Color in Doped Diphosphine-Protected Gold Nanoclusters. J. Phys. Chem. Lett. 2022, 13, 5873– 5880,  DOI: 10.1021/acs.jpclett.2c01522
    Google Scholar
    40
    Enhanced Fluorescence with Tunable Color in Doped Diphosphine-Protected Gold Nanoclusters
    She, Jie; Pei, Wei; Zhou, Si; Zhao, Jijun
    Journal of Physical Chemistry Letters (2022), 13 (25), 5873-5880CODEN: JPCLCD; ISSN:1948-7185. (American Chemical Society)
    Rational control of the luminescent properties of ligand-protected coinage metal clusters has long been pursued but remains challenging. Here we explore the crucial structural and electronic factors governing the fluorescence of a diphosphine-protected [Au13(dppe)5Cl2]3+ cluster by time-dependent d. functional theory calcns. By substituting the central Au atom with group 5 to group 11 transition metal atoms, the emission wavelength is adjustable from red to blue, accompanied by enhanced fluorescence intensity compared with the undoped cluster. The evolution of light-emitting behavior upon doping and the corresponding roles of the dopant, Au cage, ligands, and their interplay are interpreted at the electronic structure level. In particular, strong dopant-Au cage interaction assocd. with large electron-hole overlap on the dopant are is a key factor to endow large emission energy and intensity. These theor. results provide vital guidance for designing atomically precise nanoclusters with visible fluorescence and high quantum yield for practical uses.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XhsFCgt7bE&md5=d2ba604d98549244ea0cb6d793116d6a
  41. 41
    Takano, S.; Hirai, H.; Nakashima, T.; Iwasa, T.; Taketsugu, T.; Tsukuda, T. Photoluminescence of Doped Superatoms M@Au12 (M = Ru, Rh, Ir) Homoleptically Capped by (Ph2)PCH2P(Ph2): Efficient Room-Temperature Phosphorescence from Ru@Au12. J. Am. Chem. Soc. 2021, 143, 10560– 10564,  DOI: 10.1021/jacs.1c05019
    Google Scholar
    41
    Photoluminescence of Doped Superatoms M@Au12 (M = Ru, Rh, Ir) Homoleptically Capped by (Ph2)PCH2P(Ph2): Efficient Room-Temperature Phosphorescence from Ru@Au12
    Takano, Shinjiro; Hirai, Haru; Nakashima, Takuya; Iwasa, Takeshi; Taketsugu, Tetsuya; Tsukuda, Tatsuya
    Journal of the American Chemical Society (2021), 143 (28), 10560-10564CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
    A series of doped gold superatoms M@Au12 (M = Ru, Rh, Ir) was synthesized by capping with the bidentate ligand (Ph2)PCH2P(Ph2). A single-crystal X-ray diffraction anal. showed that all the M@Au12 superatoms had icosahedral motifs with a significantly higher symmetry than that of the pure Au13 counterpart due to different coordination geometries. The Ru@Au12 superatom exhibited a room-temp. phosphorescence with the highest quantum yield of 0.37 in deaerated dichloromethane. D. functional theory calcns. suggested that the efficient phosphorescence is ascribed to a rapid intersystem crossing due to the similarity between the singlet and triplet excited states in terms of structure and energy.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXhs1WmsLrO&md5=36127a9faabcc41773badb1b4841b1d4
  42. 42
    Chen, Y.; Zhou, M.; Li, Q.; Gronlund, H.; Jin, R. Isomerization-Induced Enhancement of Luminescence in Au28(SR)20 Nanoclusters. Chem. Sci. 2020, 11, 8176– 8183,  DOI: 10.1039/D0SC01270J
    Google Scholar
    42
    Isomerization-induced enhancement of luminescence in Au28(SR)20 nanoclusters
    Chen, Yuxiang; Zhou, Meng; Li, Qi; Gronlund, Harrison; Jin, Rongchao
    Chemical Science (2020), 11 (31), 8176-8183CODEN: CSHCCN; ISSN:2041-6520. (Royal Society of Chemistry)
    Understanding the origin and structural basis of the photoluminescence (PL) phenomenon in thiolate-protected metal nanoclusters is of paramount importance for both fundamental science and practical applications. It remains a major challenge to correlate the PL properties with the at.-level structure due to the complex interplay of the metal core (i.e. the inner kernel) and the exterior shell (i.e. surface Au(I)-thiolate staple motifs). Decoupling these two intertwined structural factors is crit. in order to understand the PL origin. Herein, we utilize two Au28(SR)20 nanoclusters with different -R groups, which possess the same core but different shell structures and thus provide an ideal system for the PL study. We discover that the Au28(CHT)20 (CHT: cyclohexanethiolate) nanocluster exhibits a more than 15-fold higher PL quantum yield than the Au28(TBBT)20 nanocluster (TBBT: p-tert-butylbenzenethiolate). Such an enhancement is found to originate from the different structural arrangement of the staple motifs in the shell, which modifies the electron relaxation dynamics in the inner core to different extents for the two nanoclusters. Overall, this work offers structural insights into the PL origin in Au28(SR)20 nanoclusters and provides some guidelines for designing luminescent metal nanoclusters for sensing and optoelectronic applications.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhsVSisLrF&md5=1332dbc4bcd3a52666059d07075077ef
  43. 43
    Deng, H.; Huang, K.; Xiu, L.; Sun, W.; Yao, Q.; Fang, X.; Huang, X.; Noreldeen, H. A. A.; Peng, H.; Xie, J.; Chen, W. Bis-Schiff Base Linkage-Triggered Highly Bright Luminescence of Gold Nanoclusters in Aqueous Solution at the Single-Cluster Level. Nat. Commun. 2022, 13, 3381,  DOI: 10.1038/s41467-022-30760-3
    Google Scholar
    43
    Bis-Schiff base linkage-triggered highly bright luminescence of gold nanoclusters in aqueous solution at the single-cluster level
    Deng, Haohua; Huang, Kaiyuan; Xiu, Lingfang; Sun, Weiming; Yao, Qiaofeng; Fang, Xiangyu; Huang, Xin; Noreldeen, Hamada A. A.; Peng, Huaping; Xie, Jianping; Chen, Wei
    Nature Communications (2022), 13 (1), 3381CODEN: NCAOBW; ISSN:2041-1723. (Nature Portfolio)
    Metal nanoclusters (NCs) have been developed as a new class of luminescent nanomaterials with potential applications in various fields. However, for most of the metal NCs reported so far, the relatively low photoluminescence quantum yield (QY) in aq. soln. hinders their applications. Here, we describe the utilization of bis-Schiff base linkages to restrict intramol. motion of surface motifs at the single-cluster level. Based on Au22(SG)18 (SG: glutathione) NCs, an intracluster crosslinking system was constructed with 2,6-pyridinedicarboxaldehyde (PDA), and water-sol. gold NCs with luminescence QY up to 48% were obtained. The proposed approach for achieving high emission efficiency can be extended to other luminescent gold NCs with core-shell structure. Our results also show that the content of surface-bound Au(I)-SG complexes has a significant impact on the PDA-induced luminescence enhancement, and a high ratio of Au(I)-SG will be beneficial to increasing the photoluminescence intensity of gold NCs.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XhsFGrtLvL&md5=fe2ececb4bf58943ac04afd4ca7cc010
  44. 44
    Wei, X.; Kang, X.; Jin, S.; Wang, S.; Zhu, M. Aggregation of Surface Structure Induced Photoluminescence Enhancement in Atomically Precise Nanoclusters. CCS Chem. 2021, 3, 1929– 1939,  DOI: 10.31635/ccschem.020.202000372
    Google Scholar
    There is no corresponding record for this reference.
  45. 45
    Jin, Y.; Zhang, C.; Dong, X. Y.; Zang, S. Q.; Mak, T. C. W. Shell Engineering to Achieve Modification and Assembly of Atomically-precise Silver Clusters. Chem. Soc. Rev. 2021, 50, 2297– 2319,  DOI: 10.1039/D0CS01393E
    Google Scholar
    45
    Shell engineering to achieve modification and assembly of atomically-precise silver clusters
    Jin, Yan; Zhang, Chong; Dong, Xi-Yan; Zang, Shuang-Quan; Mak, Thomas C. W.
    Chemical Society Reviews (2021), 50 (4), 2297-2319CODEN: CSRVBR; ISSN:0306-0012. (Royal Society of Chemistry)
    A review. Continuing research on the prepn. and structural detn. of monolayer-protected silver clusters has been performed. The compds. include mixed-valence Ag0/1+ clusters and single-valence Ag1+ clusters, which contain a few to tens or hundreds of Ag atoms that are protected by org. ligands. Sometimes, counter ions and extraneous species appear in their cryst. state. Atomically-precise structures help to map out definite electronic structures and structure-property correlations, enabling precise control of shell layers to achieve desired stability and specific functionalities. In this Tutorial Review, based on classic silver cluster paradigms, we first summarize the strategies and recent advances in precise modification and hierarchical assembly of well-defined silver clusters through shell engineering. Second, the correlations of structure-property and structure-functionality are summarized. Of these, the most important is structure-luminescence relationship, which is discussed in detail. In this topic, the uniqueness and prospect of silver clusters as potential lighting materials are scrutinized. Finally, the existing challenges and perspectives of functional silver clusters are presented. The general strategic design presented in this Review will motivate researchers to exploit the development of functionality-oriented materials based on nanosized building blocks in the enrichment of nanotechnol. and material science.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXht1aqtLY%253D&md5=8c113b0cbb52de6ec03eb2cb24432653
  46. 46
    Luo, L.; Liu, Z.; Du, X.; Jin, R. Near-Infrared Dual Emission from the Au42(SR)32 Nanocluster and Tailoring of Intersystem Crossing. J. Am. Chem. Soc. 2022, 144, 19243– 19247,  DOI: 10.1021/jacs.2c09107
    Google Scholar
    46
    Near-Infrared Dual Emission from the Au42(SR)32 Nanocluster and Tailoring of Intersystem Crossing
    Luo, Lianshun; Liu, Zhongyu; Du, Xiangsha; Jin, Rongchao
    Journal of the American Chemical Society (2022), 144 (42), 19243-19247CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
    This work presents the synthesis and intriguing photoluminescence of the Au42(PET)32 (PET = 2-phenylethanethiolate) nanocluster (NC). The Au42(PET)32 NC exhibits dual emission at 875 and 1040 nm, which are revealed to be fluorescence and phosphorescence, resp. The emission quantum yield (QY) of Au42(PET)32 in dichloromethane is 11.9% at room temp. in air, which is quite rare for thiolate-protected Au NCs. When Au42(PET)32 NCs are embedded in polystyrene films (solid state), the fluorescence was dramatically suppressed while the phosphorescence was significantly enhanced. This divergent behavior is explained by dipolar interaction-induced enhancement of intersystem crossing from singlet to triplet excited state.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38Xis1WltbjN&md5=4877de36eb8e307bcee4224a8293ef87
  47. 47
    Li, Y.; Song, Y.; Zhang, X.; Liu, T.; Xu, T.; Wang, H.; Jiang, D.-e.; Jin, R. Atomically Precise Au42 Nanorods with Longitudinal Excitons for an Intense Photothermal Effect. J. Am. Chem. Soc. 2022, 144, 12381– 12389,  DOI: 10.1021/jacs.2c03948
    Google Scholar
    47
    Atomically Precise Au42 Nanorods with Longitudinal Excitons for an Intense Photothermal Effect
    Li, Yingwei; Song, Yongbo; Zhang, Xinwen; Liu, Tongyu; Xu, Tingting; Wang, He; Jiang, De-en; Jin, Rongchao
    Journal of the American Chemical Society (2022), 144 (27), 12381-12389CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
    Atomically precise rod-shaped Au42(SCH2Ph)32 with a hcp. Au20 kernel of aspect ratio ≤6.2, which exhibits an intense absorption at 815 nm with a high molar absorptivity of 1.4 × 105 M-1 cm-1, are reported. Compared to other rod-shaped nanoclusters, Au42 possesses a much more effective photothermal conversion with a large temp. increase of ∼27° within 5 min (λex = 808 nm, 1 W cm-2) at an ultralow concn. of 50 μg mL-1 in toluene. D. functional theory calcns. show that the near-IR transition is mainly along the long axis of the Au20 kernel in Au42, i.e., a longitudinal excitonic oscillation, akin to the longitudinal plasmon in metallic-state nanorods. Transient absorption spectroscopy reveals that the fast decay in Au42 is similar to that of shorter-aspect-ratio nanorods but is followed by an addnl. slow decay with a long lifetime of 2400 ns for the Au42 nanorod.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38Xhs1Whu7vO&md5=f939f133acd28be6d9a5ffda4469b4a7
  48. 48
    Luo, L.; Liu, Z.; Kong, J.; Gianopoulos, C. G.; Coburn, I.; Kirschbaum, K.; Zhou, M.; Jin, R. Three-Atom-Wide Gold Quantum Rods with Periodic Elongation and Strongly Polarized Excitons. Proc. Natl. Acad. Sci. U S A 2024, 121, e2318537121  DOI: 10.1073/pnas.2318537121
    Google Scholar
    There is no corresponding record for this reference.
  49. 49
    Liu, Z.; Li, Y.; Shin, W.; Jin, R. Observation of Core Phonon in Electron-Phonon Coupling in Au25 Nanoclusters. J. Phys. Chem. Lett. 2021, 12, 1690– 1695,  DOI: 10.1021/acs.jpclett.1c00050
    Google Scholar
    49
    Observation of Core Phonon in Electron-Phonon Coupling in Au25 Nanoclusters
    Liu, Zhongyu; Li, Yingwei; Shin, Wonyong; Jin, Rongchao
    Journal of Physical Chemistry Letters (2021), 12 (6), 1690-1695CODEN: JPCLCD; ISSN:1948-7185. (American Chemical Society)
    Temp.-dependent optical properties are of paramount importance for fundamentally understanding the electron-phonon interactions and phonon modes in atomically precise nanocluster materials. In this work, low-temp. optical absorption spectra of the icosahedral [Au25(SR)18]- nanocluster are measured from room temp. down to liq. helium temp. by adopting a thin-film-based technique. The thin-film measurement is further compared with results from the previous soln.-based method. Interestingly, the previously missing core phonon is revealed by a quant. anal. of the film data through peak deconvolution and fitting of the temp. trend with a theor. model. The two lowest-energy absorption peaks (at 1.6 and 1.8 eV) of Au25 are detd. to couple with the staple-shell phonon (av. energy ~ 350 cm-1) in the soln. state, but in the solid state these electronic transitions couple with the core phonon (av. energy ~ 180 cm-1). The suppression of the staple-shell phonon in the solid state is attributed to the intracluster and cluster-matrix interactions.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXjsVSlsLk%253D&md5=95c63fd7a7dcb4611e8c9fa88e94b062
  50. 50
    Steele, J. A.; Puech, P.; Monserrat, B.; Wu, B.; Yang, R. X.; Kirchartz, T.; Yuan, H.; Fleury, G.; Giovanni, D.; Fron, E.; Keshavarz, M.; Debroye, E.; Zhou, G.; Sum, T. C.; Walsh, A.; Hofkens, J.; Roeffaers, M. B. J. Role of Electron-Phonon Coupling in the Thermal Evolution of Bulk Rashba-Like Spin-Split Lead Halide Perovskites Exhibiting Dual-Band Photoluminescence. ACS Energy Lett. 2019, 4, 2205– 2212,  DOI: 10.1021/acsenergylett.9b01427
    Google Scholar
    50
    Role of Electron-Phonon Coupling in the Thermal Evolution of Bulk Rashba-Like Spin-Split Lead Halide Perovskites Exhibiting Dual-Band Photoluminescence
    Steele, Julian A.; Puech, Pascal; Monserrat, Bartomeu; Wu, Bo; Yang, Ruo Xi; Kirchartz, Thomas; Yuan, Haifeng; Fleury, Guillaume; Giovanni, David; Fron, Eduard; Keshavarz, Masoumeh; Debroye, Elke; Zhou, Guofu; Sum, Tze Chien; Walsh, Aron; Hofkens, Johan; Roeffaers, Maarten B. J.
    ACS Energy Letters (2019), 4 (9), 2205-2212CODEN: AELCCP; ISSN:2380-8195. (American Chemical Society)
    The optoelectronic properties of lead halide perovskites strongly depend on their underlying crystal symmetries and dynamics, sometimes exhibiting a dual photoluminescence (PL) emission via Rashba-like effects. Here we exploit spin- and temp.-dependent PL to study single-crystal APbBr3 (A = Cs and methylammonium; CH3NH3) and evaluate the peak energy, intensity, and line width evolutions of their dual emission. Both perovskites exhibit temp. trends governed by two temp. regimes-above and below approx. 100 K-which impose different carrier scattering and radiative recombination dynamics. With increasing temp., high-energy optical phonons activate near 100 K to drive energy splitting of the dual bands and induce line width broadening via electron-phonon coupling, with a stronger coupling const. inferred for carriers recombining by the spin-split indirect bands, compared to the direct ones. We find that the unusual thermal evolutions of all-inorg. and hybrid bulk lead bromide perovskites are comparable, suggesting A-site independence and the dominance of dynamic effects, and are best understood within a framework that accounts for Rashba-like effects.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhsF2rs77F&md5=e56578c05dc54f6953135342afcab0fd

Cited By

Click to copy section linkSection link copied!

This article has not yet been cited by other publications.

Download PDF
Go to Journal of the American Chemical Society
Get e-Alerts
Get e-Alerts 获取 e-Alert

Journal of the American Chemical Society
美国化学会杂志

Cite this: J. Am. Chem. Soc. 2024, 146, 41, 27993–27997
引用此： J. Am. Chem. Soc.2024， 146， 41， 27993–27997
Click to copy citation 点击复制引文Citation copied!
https://doi.org/10.1021/jacs.4c11703
Published October 3, 2024
发布时间 2024 年 10 月 3 日

Copyright © 2024 The Authors. Published by American Chemical Society. This publication is licensed under
版权所有 © 2024 The Authors。由美国化学学会出版。本出版物已获得

CC-BY 4.0 .

Article Views 文章浏览量

1646

Altmetric

6

Citations 引文

-
Learn about these metrics
了解这些指标

Article Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.

Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.

The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated.

  • Abstract 抽象

    High Resolution Image
    Download MS PowerPoint Slide

    Figure 1 图 1

    Figure 1. (A) Structure of Au42(PET)32. Color code: yellow = S, other colors = Au, carbon tails are omitted for clarity. (B) Optical absorption (green) and PL (blue) spectra of Au42 dissolved in C2Cl4. (C) Optical absorption spectra, (D) PL spectra, and (E) PLQY of Au42 dissolved in deaerated 2-MeTHF containing DMBA with different concentrations. (F) The kr and knr of S1 state of Au42 in deaerated 2-MeTHF containing DMBA with different concentrations. For PL measurements: both slit widths 8 nm.
    图 1.（A） Au42（PET）32 的结构。颜色代码：黄色 = S，其他颜色 = Au，为清楚起见，省略了碳尾。（B） 溶解在 C2Cl4 中的 Au42 的光吸收（绿色）和 PL（蓝色）光谱。Au42 溶解在含有不同浓度 DMBA 的脱气 2-MeTHF 中的光吸收光谱、（D） PL 光谱和 （E） PLQY。（F） Au42 在含有不同浓度 DMBA 的脱气 2-MeTHF 中 S1 状态的 k 和 knr。对于 PL 测量：两个狭缝宽度均为 8 nm。

    High Resolution Image
    Download MS PowerPoint Slide

    Figure 2

    Figure 2. Temperature-dependent PL spectra of (A) Au42 and (B) Au42/DMBA (857.6 mM) in 2-MeTHF under a He atmosphere. Inset: the variation of total PLQY as the temperature decreases from 298 to 80 K. For PL measurements: excitation at 806 and 781 nm for Au42 and Au42/DMBA (857.6 mM), respectively, slit width 8 nm, and emission slit 8 nm. (C) Variation of QY of FL for Au42 and Au42/DMBA from 298 to 80 K. (D) Plot of kr (green symbols) and knr (yellow symbols) from 80 to 298 K. (E) Normalized integrated intensities of FL for Au42 and Au42/DMBA and fitting using eq 1 (data from panel C). (F) fwhm of the FL as a function of temperature for Au42 and Au42/DMBA and fitting using eq 2. Both eqs 1 and 2 are in the text.

    High Resolution Image
    Download MS PowerPoint Slide

    Figure 3

    Figure 3. (A) Structures of different small molecules. (B) QYs (bars) and knr (blue symbols) for Au42 mixed with different molecules.

    High Resolution Image
    Download MS PowerPoint Slide

  • References

    This article references 50 other publications.

    1. 1
      Sharma, A.; Verwilst, P.; Li, M.; Ma, D.; Singh, N.; Yoo, J.; Kim, Y.; Yang, Y.; Zhu, J. H.; Huang, H.; Hu, X. L.; He, X. P.; Zeng, L.; James, T. D.; Peng, X.; Sessler, J. L.; Kim, J. S. Theranostic Fluorescent Probes. Chem. Rev. 2024, 124, 2699– 2804,  DOI: 10.1021/acs.chemrev.3c00778
      There is no corresponding record for this reference.
    2. 2
      Lei, Z.; Zhang, F. Molecular Engineering of NIR-II Fluorophores for Improved Biomedical Detection. Angew. Chem., Int. Ed. 2021, 60, 16294– 16308,  DOI: 10.1002/anie.202007040
      2
      Molecular Engineering of NIR-II Fluorophores for Improved Biomedical Detection
      Lei, Zuhai; Zhang, Fan
      Angewandte Chemie, International Edition (2021), 60 (30), 16294-16308CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
      A review. The development of fluorophores for the second near-IR window (NIR-II, 1000-1700 nm) represents an emerging, significant, and vibrant field in analytic chem., chem. biol., and biomedical engineering. The wavelength, brightness, and stability are three crucial factors that det. the performance of an NIR-II fluorophore. Up to now, significant progress has been made in the development of NIR-II fluorescence mol. probes, including the synthesis of D-A-D and D-π-A fluorophores with improved NIR-II fluorescence imaging performance and the construction of off-on probes and ratiometric probes via energy transfer or mol. structure modification. In this review, we summarize the most recent advances in mol. engineering design strategies of NIR-II fluorophores and probes, then highlight a selection of bioimaging and biosensing applications. We also provide perspectives on potential challenges and opportunities in this emerging field.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXhvVSju78%253D&md5=847e2a9e3739ae3e6b60447f09e276ff
    3. 3
      Zampetti, A.; Minotto, A.; Cacialli, F. Near-Infrared (NIR) Organic Light-Emitting Diodes (OLEDs): Challenges and Opportunities. Adv. Funct. Mater. 2019, 29, 1807623,  DOI: 10.1002/adfm.201807623
      There is no corresponding record for this reference.
    4. 4
      Liu, H.; Hong, G.; Luo, Z.; Chen, J.; Chang, J.; Gong, M.; He, H.; Yang, J.; Yuan, X.; Li, L.; Mu, X.; Wang, J.; Mi, W.; Luo, J.; Xie, J.; Zhang, X.-D. Atomic-Precision Gold Clusters for NIR-II Imaging. Adv. Mater. 2019, 31, 1901015,  DOI: 10.1002/adma.201901015
      4
      Atomic-Precision Gold Clusters for NIR-II Imaging
      Liu, Haile; Hong, Guosong; Luo, Zhentao; Chen, Junchi; Chang, Junlei; Gong, Ming; He, Hua; Yang, Jiang; Yuan, Xun; Li, Lulin; Mu, Xiaoyu; Wang, Junying; Mi, Wenbo; Luo, Jian; Xie, Jianping; Zhang, Xiao-Dong
      Advanced Materials (Weinheim, Germany) (2019), 31 (46), 1901015CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
      Near-IR II (NIR-II) imaging at 1100-1700 nm shows great promise for medical diagnosis related to blood vessels because it possesses deep penetration and high resoln. in biol. tissue. Unfortunately, currently available NIR-II fluorophores exhibit slow excretion and low brightness, which prevents their potential medical applications. An at.-precision gold (Au) cluster with 25 gold atoms and 18 peptide ligands is presented. The Au25 clusters show emission at 1100-1350 nm and the fluorescence quantum yield is significantly increased by metal-atom doping. Bright gold clusters can penetrate deep tissue and can be applied in in vivo brain vessel imaging and tumor metastasis. Time-resolved brain blood-flow imaging shows significant differences between healthy and injured mice with different brain diseases in vivo. High-resoln. imaging of cancer metastasis allows for the identification of the primary tumor, blood vessel, and lymphatic metastasis. In addn., gold clusters with NIR-II fluorescence are used to monitor high-resoln. imaging of kidney at a depth of 0.61 cm, and the quant. measurement shows 86% of the gold clusters are cleared from body without any acute or long-term toxicity at a dose of 100 mg kg-1.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhvFSitL7E&md5=d719ced7f75e52e3901335fa54c31c88
    5. 5
      Wan, X. K.; Han, X. S.; Guan, Z. J.; Shi, W. Q.; Li, J. J.; Wang, Q. M. Interplay of Kernel Shape and Surface Structure for NIR Luminescence in Atomically Precise Gold Nanorods. Nat. Commun. 2024, 15, 7214,  DOI: 10.1038/s41467-024-51642-w
      There is no corresponding record for this reference.
    6. 6
      Ma, H.; Wang, J.; Zhang, X.-D. Near-Infrared II Emissive Metal Clusters: from Atom Physics to Biomedicine. Coord. Chem. Rev. 2021, 448, 214184,  DOI: 10.1016/j.ccr.2021.214184
      6
      Near-infrared II emissive metal clusters: From atom physics to biomedicine
      Ma, Huizhen; Wang, Junying; Zhang, Xiao-Dong
      Coordination Chemistry Reviews (2021), 448 (), 214184CODEN: CCHRAM; ISSN:0010-8545. (Elsevier B.V.)
      A review. Near-IR II (NIR-II) imaging at 1100-1700 nm supports deep tissue penetration, low auto-fluorescence interruption, and high imaging resoln. due to advances in attenuating photon scattering and absorption. For example, semiconductor quantum dots and carbon nanotubes as pioneer mol. probes were used for hind limbs and cerebrovascular imaging, and org. small mols. and polymers were employed for ultrafast and three-dimensional tumor vasculature imaging. Compared with the reported NIR-II fluorescence probe systems, the at.-precision metal clusters with unambiguous geometry structure can make the most of the spatial coordination of metal atoms by artificial atom manipulation, thus improving the luminescent quantum yield with tunable emission wavelength. Meanwhile, the water sol., renal cleanable, and highly stable features make them promising candidates for in vivo imaging. In this review, we aim to summarize the mol. and electronic structure, and optical properties of NIR-II emissive metal clusters. Meanwhile, we highlight their applications in brain, kidney, gastrointestinal imaging and tumor metastasis monitoring. We particularly reviewed recent advances on the biosafety of gold clusters at ultrahigh concn. Present work will promote the development of NIR-II imaging and make a step toward the clin. application.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXhvFyhsLjO&md5=14d54c66391495e3cb4d9dd57928fb6e
    7. 7
      Wang, F.; Zhong, Y.; Bruns, O.; Liang, Y.; Dai, H. In vivo NIR-II Fluorescence Imaging for Biology and Medicine. Nat. Photonics 2024, 18, 535– 547,  DOI: 10.1038/s41566-024-01391-5
      There is no corresponding record for this reference.
    8. 8
      Du, B.; Jiang, X.; Das, A.; Zhou, Q.; Yu, M.; Jin, R.; Zheng, J. Glomerular Barrier Behaves as an Atomically Precise Bandpass Filter in a Sub-Nanometre Regime. Nat. Nanotechnol. 2017, 12, 1096– 1102,  DOI: 10.1038/nnano.2017.170
      8
      Glomerular barrier behaves as an atomically precise bandpass filter in a sub-nanometre regime
      Du, Bujie; Jiang, Xingya; Das, Anindita; Zhou, Qinhan; Yu, Mengxiao; Jin, Rongchao; Zheng, Jie
      Nature Nanotechnology (2017), 12 (11), 1096-1102CODEN: NNAABX; ISSN:1748-3387. (Nature Research)
      The glomerular filtration barrier is known as a 'size cutoff' slit, which retains nanoparticles or proteins larger than 6-8 nm in the body and rapidly excretes smaller ones through the kidneys. However, in the sub-nanometer size regime, we have found that this barrier behaves as an atomically precise 'bandpass' filter to significantly slow down renal clearance of few-atom gold nanoclusters (AuNCs) with the same surface ligands but different sizes (Au18, Au15 and Au10-11). Compared to Au25 (∼1.0 nm), just few-atom decreases in size result in four- to ninefold redns. in renal clearance efficiency in the early elimination stage, because the smaller AuNCs are more readily trapped by the glomerular glycocalyx than larger ones. This unique in vivo nano-bio interaction in the sub-nanometer regime also slows down the extravasation of sub-nanometer AuNCs from normal blood vessels and enhances their passive targeting to cancerous tissues through an enhanced permeability and retention effect. This discovery highlights the size precision in the body's response to nanoparticles and opens a new pathway to develop nanomedicines for many diseases assocd. with glycocalyx dysfunction.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhsVKlu7fN&md5=2f0c1bbabc9acf9b07e9fcb75ee99e47
    9. 9
      Li, Y.; Zhou, M.; Song, Y.; Higaki, T.; Wang, H.; Jin, R. Double-Helical Assembly of Heterodimeric Nanoclusters into Supercrystals. Nature 2021, 594, 380– 384,  DOI: 10.1038/s41586-021-03564-6
      9
      Double-helical assembly of heterodimeric nanoclusters into supercrystals
      Li, Yingwei; Zhou, Meng; Song, Yongbo; Higaki, Tatsuya; Wang, He; Jin, Rongchao
      Nature (London, United Kingdom) (2021), 594 (7863), 380-384CODEN: NATUAS; ISSN:0028-0836. (Nature Portfolio)
      DNA has long been used as a template for the construction of helical assemblies of inorg. nanoparticles1-5. For example, gold nanoparticles decorated with DNA (or with peptides) can create helical assemblies6-9. But without such biol. ligands, helixes are difficult to achieve and their mechanism of formation is challenging to understand10,11. Atomically precise nanoclusters that are protected by ligands such as thiolate12,13 have demonstrated hierarchical structural complexity in their assembly at the interparticle and intraparticle levels, similar to biomols. and their assemblies14. Furthermore, carrier dynamics can be controlled by engineering the structure of the nanoclusters15. But these nanoclusters usually have isotropic structures16,17 and often assemble into commonly found supercrystals18. Here we report the synthesis of homodimeric and heterodimeric gold nanoclusters and their self-assembly into superstructures. While the homodimeric nanoclusters form layer-by-layer superstructures, the heterodimeric nanoclusters self-assemble into double- and quadruple-helical superstructures. These complex arrangements are the result of two different motif pairs, one pair per monomer, where each motif bonds with its paired motif on a neighboring heterodimer. This motif pairing is reminiscent of the paired interactions of nucleobases in DNA helixes. Meanwhile, the surrounding ligands on the clusters show doubly or triply paired steric interactions. The helical assembly is driven by van der Waals interactions through particle rotation and conformational matching. Furthermore, the heterodimeric clusters have a carrier lifetime that is roughly 65 times longer than that of the homodimeric clusters. Our findings suggest new approaches for increasing complexity in the structural design and engineering of precision in supercrystals.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXhtleqsLvN&md5=eead4fc70b29dfddacaf1ea2b94f57c4
    10. 10
      Kang, X.; Zhu, M. Tailoring the Photoluminescence of Atomically Precise Nanoclusters. Chem. Soc. Rev. 2019, 48, 2422– 2457,  DOI: 10.1039/C8CS00800K
      10
      Tailoring the photoluminescence of atomically precise nanoclusters
      Kang, Xi; Zhu, Manzhou
      Chemical Society Reviews (2019), 48 (8), 2422-2457CODEN: CSRVBR; ISSN:0306-0012. (Royal Society of Chemistry)
      A review. Due to their atomically precise structures and intriguing chem./phys. properties, metal nanoclusters are an emerging class of modular nanomaterials. Photo-luminescence (PL) is one of their most fascinating properties, due to the plethora of promising PL-based applications, such as chem. sensing, bio-imaging, cell labeling, phototherapy, drug delivery, and so on. However, the PL of most current nanoclusters is still unsatisfactory-the PL quantum yield (QY) is relatively low (generally lower than 20%), the emission lifetimes are generally in the nanosecond range, and the emitted color is always red (emission wavelengths of above 630 nm). To address these shortcomings, several strategies have been adopted, and are reviewed herein: capped-ligand engineering, metallic kernel alloying, aggregation-induced emission, self-assembly of nanocluster building blocks into cluster-based networks, and adjustments on external environment factors. We further review promising applications of these fluorescent nanoclusters, with particular focus on their potential to impact the fields of chem. sensing, bio-imaging, and bio-labeling. Finally, scope for improvements and future perspectives of these novel nanomaterials are highlighted as well. Our intended audience is the broader scientific community interested in the fluorescence of metal nanoclusters, and our review hopefully opens up new horizons for these scientists to manipulate PL properties of nanoclusters. This review is based on publications available up to Dec. 2018.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXkt1Wqt7k%253D&md5=a25d2e3afdc1a6d81551c0edc0d36b02
    11. 11
      Biswas, S.; Das, A. K.; Mandal, S. Surface Engineering of Atomically Precise M(I) Nanoclusters: From Structural Control to Room Temperature Photoluminescence Enhancement. Acc. Chem. Res. 2023, 56, 1838– 1849,  DOI: 10.1021/acs.accounts.3c00176
      11
      Surface Engineering of Atomically Precise M(I) Nanoclusters: From Structural Control to Room Temperature Photoluminescence Enhancement
      Biswas, Sourav; Das, Anish Kumar; Mandal, Sukhendu
      Accounts of Chemical Research (2023), 56 (13), 1838-1849CODEN: ACHRE4; ISSN:0001-4842. (American Chemical Society)
      A review is presented on the structural control and Photoluminescence enhancement through surface engineering of atomically precise M(I) nanoclusters. Understanding the structural architecture of nanoparticles is essential for investigating their fundamental properties because these materials have become more desirable in modern nanoscience research. Designing a proper synthetic strategy to control their growth with at. precision is crucial. The polydispersed nature of the nanoparticles makes detg. their precise structural information challenging. Metal nanoclusters (NCs) have emerged as a promising soln. to this problem as they bridge the gap between metal nanoparticles and discrete mol. complexes. Well-ordered mol. structures provide opportunities to look at structure-property correlations and find quantum confinement effects at the at. level that reveal their similarity to mol.-like properties. While most M(0)/(I)-based NCs exhibit exceptional photoluminescence (PL) emission at room temp., M(I)-based NCs are less likely to exhibit PL emissions due to their electronic environment. Developments in the field of metal nanoparticles have made it intriguing to achieve room-temp. PL emission in M(I) NCs. Efforts have focused on developing efficient methods for prepg. luminescent M(I) NCs to better comprehend fundamental aspects of their PL emission properties. The authors provide an overview of various synthetic strategies for prepg. NCs and their selective functionalization for generating room-temp. PL emissions. The authors' focus was creating an Ag(I) NC with a core-shell architecture, as this unique structural design complements the charge transition phenomenon. The mol. structure obtained from single-crystal x-ray diffraction (SCXRD) and assocd. theor. calcn. revealed that the authors' effort results in a unique hexagonal closed pack core and Keplerate shell contg. [S@Ag50S12(StBu)20]4+ NC where the charge transition between the core and the metal-ligand shell facilitates emission properties. The authors also explored the approach of host-guest supramol. adduct formations to engineer the surface of ligands that reduce nonradiative relaxation rates by restricting surface mol. vibrations and controlling the generation of PL emission. To do this, the authors capped precisely structured [Cl@Ag16S(S-Adm)8(CF3COO)5(DMF)3(H2O)2]·DMF with β-cyclodextrin via adamantane moieties. The authors also describe the effects of bimetallic cluster formation on increasing surface rigidity and modulating the frontier MO arrangement, which helps to attain synergy to generate room-temp. PL emission. The authors focused on the structural integrity of Ag(I) NCs, allowing the authors to incorporate heterometal atoms at peripheral positions that give [CO2@Ag20Cu2S2(StBu)10(CF3COO)8(DMA)4]·(DMA). The authors also explored the impact of introducing extra ligands into the Ag(I) cluster node on the generation of PL emission at room-temp. These strategies are not limited to Ag NCs. The authors discussed the possibility of combining core-shell architecture and surface modifications to enhance PL emission in [Cu18H3(S-Adm)12(PPh3)4Cl2] NC at room temp. SCXRD studies revealed its distinct core-shell architecture that ensures electronic transitions and that transition is controlled by the imposed surface rigidity that yields a higher PL emission. The authors believe that this innovative structural engineering holds potential for the advancement of NC research, and this Account will inspire the scientific community to synthesize functional M(I) NCs.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXht1Oms73L&md5=9cc1e1e53a9761366813b35dae742939
    12. 12
      Lin, H.; Song, X.; Chai, O. J. H.; Yao, Q.; Yang, H.; Xie, J. Photoluminescent Characterization of Metal Nanoclusters: Basic Parameters, Methods, and Applications. Adv. Mater. 2024, 36, e2401002  DOI: 10.1002/adma.202401002
      There is no corresponding record for this reference.
    13. 13
      Albright, E. L.; Levchenko, T. I.; Kulkarni, V. K.; Sullivan, A. I.; DeJesus, J. F.; Malola, S.; Takano, S.; Nambo, M.; Stamplecoskie, K.; Hakkinen, H.; Tsukuda, T.; Crudden, C. M. N-Heterocyclic Carbene-Stabilized Atomically Precise Metal Nanoclusters. J. Am. Chem. Soc. 2024, 146, 5759– 5780,  DOI: 10.1021/jacs.3c11031
      13
      N-Heterocyclic Carbene-Stabilized Atomically Precise Metal Nanoclusters
      Albright, Emily L.; Levchenko, Tetyana I.; Kulkarni, Viveka K.; Sullivan, Angus I.; DeJesus, Joseph F.; Malola, Sami; Takano, Shinjiro; Nambo, Masakazu; Stamplecoskie, Kevin; Hakkinen, Hannu; Tsukuda, Tatsuya; Crudden, Cathleen M.
      Journal of the American Chemical Society (2024), 146 (9), 5759-5780CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
      This perspective highlights advances in the prepn. and understanding of metal nanoclusters stabilized by org. ligands with a focus on N-heterocyclic carbenes (NHCs). We demonstrate the need for a clear understanding of the relationship between NHC properties and their resulting metal nanocluster structure and properties. We emphasize the importance of balancing nanocluster stability with the introduction of reactive sites for catalytic applications and the importance of a better understanding of how these clusters interact with their environments for effective use in biol. applications. The impact of atom-scale simulations, development of at. interaction potentials suitable for large-scale mol. dynamics simulations, and a deeper understanding of the mechanisms behind synthetic methods and phys. properties (e.g., the bright fluorescence displayed by many clusters) are emphasized.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB2cXjsleisbc%253D&md5=1a22399ab03078760e3f67e3c14e8aec
    14. 14
      Huang, Y.-Z.; Gupta, R. K.; Luo, G.-G.; Zhang, Q.-C.; Sun, D. Luminescence Thermochromism in Atomically Precise Silver Custers: A Comprehensive Review. Coord. Chem. Rev. 2024, 499, 215508,  DOI: 10.1016/j.ccr.2023.215508
      There is no corresponding record for this reference.
    15. 15
      Shi, W.-Q.; Zeng, L.; He, R.-L.; Han, X.-S.; Guan, Z.-J.; Zhou, M.; Wang, Q.-M. Near-Unity NIR Phosphorescent Quantum Yield from a Room-Temperature Solvated Metal Nanocluster. Science 2024, 383, 326– 330,  DOI: 10.1126/science.adk6628
      There is no corresponding record for this reference.
    16. 16
      Jin, R.; Zeng, C.; Zhou, M.; Chen, Y. Atomically Precise Colloidal Metal Nanoclusters and Nanoparticles: Fundamentals and Opportunities. Chem. Rev. 2016, 116, 10346– 10413,  DOI: 10.1021/acs.chemrev.5b00703
      16
      Atomically Precise Colloidal Metal Nanoclusters and Nanoparticles: Fundamentals and Opportunities
      Jin, Rongchao; Zeng, Chenjie; Zhou, Meng; Chen, Yuxiang
      Chemical Reviews (Washington, DC, United States) (2016), 116 (18), 10346-10413CODEN: CHREAY; ISSN:0009-2665. (American Chemical Society)
      A review. Colloidal nanoparticles are being intensely pursued in current nanoscience research. Nanochemists are often frustrated by the known fact that no two nanoparticles are the same, which precludes the deep understanding of many fundamental properties of colloidal nanoparticles in which the total structures (core plus surface) must be known. Therefore, controlling nanoparticles with at. precision and solving their total structures have long been major dreams for nanochemists. Recently, these goals are partially fulfilled in the case of gold nanoparticles, at least in the ultrasmall size regime (1-3 nm in diam., often called nanoclusters). This review summarizes the major progress in the field, including the principles that permit atomically precise synthesis, new types of at. structures, and unique phys. and chem. properties of atomically precise nanoparticles, as well as exciting opportunities for nanochemists to understand very fundamental science of colloidal nanoparticles (such as the stability, metal-ligand interfacial bonding, ligand assembly on particle surfaces, aesthetic structural patterns, periodicities, and emergence of the metallic state) and to develop a range of potential applications such as in catalysis, biomedicine, sensing, imaging, optics, and energy conversion. Although most of the research activity currently focuses on thiolate-protected gold nanoclusters, important progress also was achieved in other ligand-protected gold, silver, and bimetal (or alloy) nanoclusters. All of these types of unique nanoparticles will bring unprecedented opportunities, not only in understanding the fundamental questions of nanoparticles but also in opening up new horizons for scientific studies of nanoparticles.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhsVeksLnJ&md5=aa1208c72c4e8de1be9a4a906a9bc6c9
    17. 17
      Xia, N.; Wu, Z. Controlling Ultrasmall Gold Nanoparticles with Atomic Precision. Chem. Sci. 2021, 12, 2368– 2380,  DOI: 10.1039/D0SC05363E
      17
      Controlling ultrasmall gold nanoparticles with atomic precision
      Xia, Nan; Wu, Zhikun
      Chemical Science (2021), 12 (7), 2368-2380CODEN: CSHCCN; ISSN:2041-6520. (Royal Society of Chemistry)
      A review. Gold nanoparticles are probably the nanoparticles that have been best studied for the longest time due to their stability, physicochem. properties and applications. Controlling gold nanoparticles with at. precision is of significance for subsequent research on their structures, properties and applications, which is a dream that has been pursued for many years since ruby gold was first obtained by Faraday in 1857. Fortunately, this dream has recently been partially realized for some ultrasmall gold nanoparticles (nanoclusters). However, rationally designing and synthesizing gold nanoparticles with at. precision are still distant goals, and this challenge might rely primarily on rich atomically precise gold nanoparticle libraries and the in-depth understanding of metal nanoparticle chem. Herein, we review general synthesis strategies and some facile synthesis methods, with an emphasis on the controlling parameters detd. from well-documented results, which might have important implications for future nanoparticle synthesis with at. precision and facilitate related research and applications.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXis1Kku7%252FK&md5=c736748e4abdc913e91f79416a471caa
    18. 18
      Luo, Z.; Yuan, X.; Yu, Y.; Zhang, Q.; Leong, D. T.; Lee, J. Y.; Xie, J. From Aggregation-Induced Emission of Au(I)-Thiolate Complexes to Ultrabright Au(0)@Au(I)-Thiolate Core-Shell Nanoclusters. J. Am. Chem. Soc. 2012, 134, 16662– 16670,  DOI: 10.1021/ja306199p
      18
      From Aggregation-Induced Emission of Au(I)-Thiolate Complexes to Ultrabright Au(0)@Au(I)-Thiolate Core-Shell Nanoclusters
      Luo, Zhentao; Yuan, Xun; Yu, Yue; Zhang, Qingbo; Leong, David Tai; Lee, Jim Yang; Xie, Jianping
      Journal of the American Chemical Society (2012), 134 (40), 16662-16670CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
      A fundamental understanding of the luminescence of Au-thiolate nanoclusters (NCs), such as the origin of emission and the size effect in luminescence, is pivotal to the development of efficient synthesis routes for highly luminescent Au NCs. This paper reports an interesting finding of Au(I)-thiolate complexes: strong luminescence emission by the mechanism of aggregation-induced emission (AIE). The AIE property of the complexes was then used to develop a simple 1-pot synthesis of highly luminescent Au-thiolate NCs with a quantum yield of ∼15%. Key strategy was to induce the controlled aggregation of Au(I)-thiolate complexes on in situ generated Au(0) cores to form Au(0)@Au(I)-thiolate core-shell NCs where strong luminescence was generated by the AIE of Au(I)-thiolate complexes on the NC surface. The authors were able to extend the synthetic strategy to other thiolate ligands with added functionalities (as custom-designed peptides). The discovery (e.g., identifying the source of emission and the size effect in luminescence) and the synthesis protocols in this study can contribute significantly to better understanding of these new luminescence probes and the development of new synthetic routes.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhtl2mu7nO&md5=3ffed2ce6a4724ccddcb4187a8dcc8cc
    19. 19
      Liu, Z.; Luo, L.; Jin, R. Visible to NIR-II Photoluminescence of Atomically Precise Gold Nanoclusters. Adv. Mater. 2024, 36, e2309073  DOI: 10.1002/adma.202309073
      There is no corresponding record for this reference.
    20. 20
      Si, W.-D.; Zhang, C.; Zhou, M.; Wang, Z.; Feng, L.; Tung, C.-H.; Sun, D. Arylgold nanoclusters: Phenyl-Stabilized Au44 with Thermal-Controlled NIR Single/Dual-Channel Phosphorescence. Sci. Adv. 2024, 10, eadm6928  DOI: 10.1126/sciadv.adm6928
      There is no corresponding record for this reference.
    21. 21
      Hirai, H.; Takano, S.; Nakashima, T.; Iwasa, T.; Taketsugu, T.; Tsukuda, T. Doping-Mediated Energy-Level Engineering of M@Au12 Superatoms (M = Pd, Pt, Rh, Ir) for Efficient Photoluminescence and Photocatalysis. Angew. Chem., Int. Ed. 2022, 61, e202207290  DOI: 10.1002/anie.202207290
      21
      Doping-Mediated Energy-Level Engineering of M@Au12 Superatoms (M=Pd, Pt, Rh, Ir) for Efficient Photoluminescence and Photocatalysis
      Hirai, Haru; Takano, Shinjiro; Nakashima, Takuya; Iwasa, Takeshi; Taketsugu, Tetsuya; Tsukuda, Tatsuya
      Angewandte Chemie, International Edition (2022), 61 (36), e202207290CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
      We synthesized a series of MAu12(dppe)5Cl2 (MAu12; M=Au, Pd, Pt, Rh, or Ir; dppe=1,2-bis(diphenylphosphino)ethane), which have icosahedral M@Au12 superat. cores, and systematically investigated their electronic structures, photoluminescence (PL) and photocatalytic properties. The energy gap between the HOMO (HOMO) and the LUMO (LUMO) was expanded when doping an M element positioned at the lower left of the periodic table. The PL quantum yield was enhanced with an increase in the HOMO-LUMO gap and reached 0.46-0.67 for MAu12 (M=Pt, Rh, or Ir) under deaerated conditions. The bright PLs from MAu12 (M=Pt, Rh, or Ir) were assigned to phosphorescence based on quenching by O2. MAu12 (M=Pt, Rh, or Ir) acted as a more efficient and stable photocatalyst than Au13 for intramol. [2+2] cycloaddn. of bisenone via the oxidative quenching cycle. This study provides rational guides for designing photoluminescent and photocatalytic gold superatoms by the doping of heterometal elements.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38Xhs1ClsbfK&md5=08cbb15c9854b3d47cd72bac6134e756
    22. 22
      Yang, G.; Pan, X.; Feng, W.; Yao, Q.; Jiang, F.; Du, F.; Zhou, X.; Xie, J.; Yuan, X. Engineering Au44 Nanoclusters for NIR-II Luminescence Imaging-Guided Photoactivatable Cancer Immunotherapy. ACS Nano 2023, 17, 15605– 15614,  DOI: 10.1021/acsnano.3c02370
      22
      Engineering Au44 Nanoclusters for NIR-II Luminescence Imaging-Guided Photoactivatable Cancer Immunotherapy
      Yang, Ge; Pan, Xinxin; Feng, Wenbi; Yao, Qiaofeng; Jiang, Fuyi; Du, Fanglin; Zhou, Xianfeng; Xie, Jianping; Yuan, Xun
      ACS Nano (2023), 17 (16), 15605-15614CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
      Immunotherapy is an advanced therapeutic strategy of cancer treatment but suffers from the issues of off-target adverse effects, lack of real-time monitoring techniques, and unsustainable response. Herein, an ultrasmall Au nanocluster (NC)-based theranostic probe is designed for second near-IR window (NIR-II) photoluminescence (PL) imaging-guided phototherapies and photoactivatable cancer immunotherapy. The probe (Au44MBA26-NLG for short) is composed of atomically precise and NIR-II emitting Au44MBA26 NCs (here MBA denotes water-sol. 4-mercaptobenzoic acid) conjugated with immune checkpoint inhibitor 1-cyclohexyl-2-(5H-imidazo[5,1-a]isoindol-5-yl)ethanol (NLG919) via a singlet oxygen (1O2)-cleavable linker. Upon NIR photoirradn., the Au44MBA26-NLG not only enables NIR-II PL imaging of tumors in deep tissues for guiding tumor therapy but also allows the leverage of photothermal property for cancer photothermal therapy (PTT) and the photogenerated 1O2 for photodynamic therapy (PDT) and releasing NLG919 for cancer immunotherapy. Such a multiple effect modulated by Au44MBA26-NLG prompts the proliferation and activation of effector T cells, upshifts systemic antitumor T-lymphocyte (T cell) immunity, and finally suppresses the growth of both primary and distant tumors in living mice. Overall, this study may provide a promising theranostic nanoplatform toward NIR-II PL imaging-guided phototherapies and photoactivatable cancer immunotherapy.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXhsFCrtbzP&md5=084a7ae2b85e03a54f04075cd6258bbc
    23. 23
      Weerawardene, K. L.; Aikens, C. M. Theoretical Insights into the Origin of Photoluminescence of Au25(SR)18– Nanoparticles. J. Am. Chem. Soc. 2016, 138, 11202– 11210,  DOI: 10.1021/jacs.6b05293
      23
      Theoretical Insights into the Origin of Photoluminescence of Au25(SR)18- Nanoparticles
      Weerawardene, K. L. Dimuthu M.; Aikens, Christine M.
      Journal of the American Chemical Society (2016), 138 (35), 11202-11210CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
      Understanding fundamental behavior of luminescent nanomaterials upon photoexcitation is necessary to expand photocatalytic and biol. imaging applications. Despite the significant amt. of exptl. work into the luminescence of Au25(SR)18- clusters, the origin of photoluminescence in these clusters still remains unclear. The geometric and electronic structural changes of the Au25(SR)18- (R = H, CH3, CH2CH3, CH2CH2CH3) nanoclusters upon photoexcitation are discussed using time-dependent d. functional theory (TD-DFT) methods. Geometric relaxations in the optimized excited states of up to 0.33 Å impart remarkable effects on the energy levels of the frontier orbitals of Au25(SR)18- nanoclusters. This gives rise to a Stokes shift of 0.49 eV for Au25(SH)18- in agreement with expts. Even larger Stokes shifts are predicted for longer ligands. Vibrational frequencies in the 75-80 cm-1 range are calcd. for the nuclear motion involved in the excited-state nuclear relaxation; this value is in excellent agreement with vibrational beating obsd. in time-resolved spectroscopy expts. Several excited states around 0.8, 1.15, and 1.25 eV are calcd. for the Au25(SH)18- nanocluster. Considering the typical underestimation of DFT excitation energies, these states are likely responsible for the emission obsd. exptl. in the 1.15-1.55 eV range. All excited states arise from core-based orbitals; charge-transfer states or other semi-ring or ligand-based states are not implicated.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhtleiurfK&md5=70c4d2ccd967529df54ab7d5f1fe3ca7
    24. 24
      Liu, Z.; Zhou, M.; Luo, L.; Wang, Y.; Kahng, E.; Jin, R. Elucidating the Near-Infrared Photoluminescence Mechanism of Homometal and Doped M25(SR)18 Nanoclusters. J. Am. Chem. Soc. 2023, 145, 19969– 19981,  DOI: 10.1021/jacs.3c06543
      24
      Elucidating the Near-Infrared Photoluminescence Mechanism of Homometal and Doped M25(SR)18 Nanoclusters
      Liu, Zhongyu; Zhou, Meng; Luo, Lianshun; Wang, Yitong; Kahng, Ellen; Jin, Rongchao
      Journal of the American Chemical Society (2023), 145 (36), 19969-19981CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
      More than a decade of research on the photoluminescence (PL) of classic Au25(SR)18 and its doped nanoclusters (NCs) still leaves many fundamental questions unanswered due to the complex electron dynamics. Here, the authors revisit the homogold Au25 (ligands omitted hereafter) and doped NCs, as well as the Ag25 and doped ones, for a comparative study to disentangle the influencing factors and elucidate the PL mechanism. The strong electron-vibration coupling in Au25 leads to weak PL in the near-IR region (~ 1000 nm, quantum yield QY = 1% in soln. at room temp.). Heteroatom doping of Au25 with a single Cd or Hg atom strengthens the coupling of the exciton with staple vibrations but reduces the coupling with the core breathing and quadrupolar modes. The QYs of the three MAu24 NCs (M = Hg, Au, and Cd) follow a linear relation with their PL lifetimes, suggesting a mechanism of suppressed nonradiative decay in PL enhancement. In contrast, the weaker electron-vibration coupling in Ag25 leads to higher PL (QY = 3.5%), and single Au atom doping further leads to a 5x enhancement of the radiative rate and a suppression of nonradiative decay rate (i.e., twice the PL lifetime of Ag25) in AuAg24 (hence, QY 35%), but doping more Au atoms results in Au distribution to staple motifs and thus triggering of strong electron-vibration coupling as in the MAu24 NCs, hence, counteracting the radiative enhancement effect and giving rise to only 5% QY for AuxAg25-x (x = 3-10). The obtained insights will provide guidance for the design of metal NCs with high PL for lighting, sensing, and optoelectronic applications.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXhslOlsLvL&md5=b7ae109a5a40639e5ae79be065f692e9
    25. 25
      Pyo, K.; Thanthirige, V. D.; Kwak, K.; Pandurangan, P.; Ramakrishna, G.; Lee, D. Ultrabright Luminescence from Gold Nanoclusters: Rigidifying the Au(I)-Thiolate Shell. J. Am. Chem. Soc. 2015, 137, 8244– 8250,  DOI: 10.1021/jacs.5b04210
      25
      Ultrabright Luminescence from Gold Nanoclusters: Rigidifying the Au(I)-Thiolate Shell
      Pyo, Kyunglim; Thanthirige, Viraj Dhanushka; Kwak, Kyuju; Pandurangan, Prabhu; Ramakrishna, Guda; Lee, Dongil
      Journal of the American Chemical Society (2015), 137 (25), 8244-8250CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
      Luminescent nanomaterials have captured the imagination of scientists for a long time and offer great promise for applications in org./inorg. light-emitting displays, optoelectronics, optical sensors, biomedical imaging, and diagnostics. Atomically precise gold clusters with well-defined core-shell structures present bright prospects to achieve high photoluminescence efficiencies. In this study, gold clusters with a luminescence quantum yield greater than 60% were synthesized based on the Au22(SG)18 cluster, where SG is glutathione, by rigidifying its gold shell with tetraoctylammonium (TOA) cations. Time-resolved and temp.-dependent optical measurements on Au22(SG)18 have shown the presence of high quantum yield visible luminescence below freezing, indicating that shell rigidity enhances the luminescence quantum efficiency. To achieve high rigidity of the gold shell, Au22(SG)18 was bound to bulky TOA that resulted in greater than 60% quantum yield luminescence at room temp. Optical measurements have confirmed that the rigidity of gold shell was responsible for the luminescence enhancement. This work presents an effective strategy to enhance the photoluminescence efficiencies of gold clusters by rigidifying the Au(I)-thiolate shell.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhtVagtbjO&md5=3c27c44f816be68faa74df06229ed369
    26. 26
      Ma, X. H.; Li, J.; Luo, P.; Hu, J. H.; Han, Z.; Dong, X. Y.; Xie, G.; Zang, S. Q. Carbene-Stabilized Enantiopure Heterometallic Clusters Featuring EQE of 20.8% in Circularly-Polarized OLED. Nat. Commun. 2023, 14, 4121,  DOI: 10.1038/s41467-023-39802-w
      26
      Carbene-stabilized enantiopure heterometallic clusters featuring EQE of 20.8% in circularly-polarized OLED
      Ma, Xiao-Hong; Li, Jing; Luo, Peng; Hu, Jia-Hua; Han, Zhen; Dong, Xi-Yan; Xie, Guohua; Zang, Shuang-Quan
      Nature Communications (2023), 14 (1), 4121CODEN: NCAOBW; ISSN:2041-1723. (Nature Portfolio)
      Bright and efficient chiral coinage metal clusters show promise for use in emerging circularly polarized light-emitting materials and diodes. To date, highly efficient circularly polarized org. light-emitting diodes (CP-OLEDs) with enantiopure metal clusters have not been reported. Herein, through rational design of a multidentate chiral N-heterocyclic carbene (NHC) ligand and a modular building strategy, we synthesize a series of enantiopure Au(I)-Cu(I) clusters with exceptional stability. Modulation of the ligands stabilize the chiral excited states of clusters to allow thermally activated delayed fluorescence, resulting in the highest orange-red photoluminescence quantum yields over 93.0% in the solid state, which is accompanied by circularly polarized luminescence. Based on the soln. process, a prototypical orange-red CP-OLED with a considerably high external quantum efficiency of 20.8% is prepd. These results demonstrate the extensive designability of chiral NHC ligands to stabilize polymetallic clusters for high performance in chiroptical applications.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXhsVKms7nN&md5=68051f6d4f9352283ce7c26e3041b82e
    27. 27
      Zhong, Y.; Zhang, J.; Li, T.; Xu, W.; Yao, Q.; Lu, M.; Bai, X.; Wu, Z.; Xie, J.; Zhang, Y. Suppression of Kernel Vibrations by Layer-by-Layer Ligand Engineering Boosts Photoluminescence Efficiency of Gold Nanoclusters. Nat. Commun. 2023, 14, 658,  DOI: 10.1038/s41467-023-36387-2
      27
      Suppression of kernel vibrations by layer-by-layer ligand engineering boosts photoluminescence efficiency of gold nanoclusters
      Zhong, Yuan; Zhang, Jiangwei; Li, Tingting; Xu, Wenwu; Yao, Qiaofeng; Lu, Min; Bai, Xue; Wu, Zhennan; Xie, Jianping; Zhang, Yu
      Nature Communications (2023), 14 (1), 658CODEN: NCAOBW; ISSN:2041-1723. (Nature Portfolio)
      The restriction of structural vibration has assumed great importance in attaining bright emission of luminescent metal nanoclusters (NCs), where tremendous efforts are devoted to manipulating the surface landscape yet remain challenges for modulation of the structural vibration of the metal kernel. Here, we report efficient suppression of kernel vibration achieving enhancement in emission intensity, by rigidifying the surface of metal NCs and propagating as-developed strains into the metal core. Specifically, a layer-by-layer triple-ligands surface engineering is deployed to allow the soln.-phase Au NCs with strong metal core-dictated fluorescence, up to the high abs. quantum yields of 90.3 ± 3.5%. The as-rigidified surface imposed by synergistic supramol. interactions greatly influences the low-frequency acoustic vibration of the metal kernel, resulting in a subtle change in vibration frequency but a redn. in amplitude of oscillation. This scenario therewith impedes the non-radiative relaxation of electron dynamics, rendering the Au NCs with strong emission. The presented study exemplifies the linkage between surface chem. and core-state emission of metal NCs, and proposes a strategy for brighter emitting metal NCs by regulating their interior metal core-involved motion.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXjtVWqtbY%253D&md5=d68cb1b147309c3b18630de34df5056e
    28. 28
      Dong, J.; Gan, Z.; Gu, W.; You, Q.; Zhao, Y.; Zha, J.; Li, J.; Deng, H.; Yan, N.; Wu, Z. Synthesizing Photoluminescent Au28(SCH2Ph-tBu)22 Nanoclusters with Structural Features by Using a Combined Method. Angew. Chem., Int. Ed. 2021, 60, 17932– 17936,  DOI: 10.1002/anie.202105530
      28
      Synthesizing Photoluminescent Au28(SCH2Ph-tBu)22 Nanoclusters with Structural Features by Using A Combined Method
      Dong, Jingwu; Gan, Zibao; Gu, Wanmiao; You, Qing; Zhao, Yan; Zha, Jun; Li, Jin; Deng, Haiteng; Yan, Nan; Wu, Zhikun
      Angewandte Chemie, International Edition (2021), 60 (33), 17932-17936CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
      We present a method for atomically precise nanocluster synthesis. As an illustration, we introduced the reducing-ligand induction combined method and synthesized a novel nanocluster, which was detd. to be Au28(SCH2Ph-tBu)22 with the same no. of gold atoms as existing Au28(SR)20 nanoclusters but different ligands (hetero-compn.-homo-size). Compared with the latter, the former has distinct properties and structures. In particular, a novel kernel evolution pattern is reported, i.e., the quasi-linear growth of Au4-tetrahedron by sharing one vertex and structural features, including a tritetrahedron kernel with two bridging thiolates and two Au6(SCH2Ph-tBu)6 hexamer chair-like rings on the kernel surface were also first reported, which endow Au28(SCH2Ph-tBu)22 with the best photoluminescence quantum yield among hydrophobic thiolated gold nanoclusters so far, probably due to the enhanced charge transfer from the bi-ring to the kernel via Au-Au bonds.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXhs1ems7zJ&md5=ac18a8c8c882429b97af4def1f7823b3
    29. 29
      Peng, Q. C.; Si, Y. B.; Wang, Z. Y.; Dai, S. H.; Chen, Q. S.; Li, K.; Zang, S. Q. Thermally Activated Delayed Fluorescence Coinage Metal Cluster Scintillator. ACS Cent. Sci. 2023, 9, 1419– 1426,  DOI: 10.1021/acscentsci.3c00563
      29
      Thermally Activated Delayed Fluorescence Coinage Metal Cluster Scintillator
      Peng, Qiu-Chen; Si, Yu-Bing; Wang, Zhao-Yang; Dai, Shu-Heng; Chen, Qiu-Shui; Li, Kai; Zang, Shuang-Quan
      ACS Central Science (2023), 9 (7), 1419-1426CODEN: ACSCII; ISSN:2374-7951. (American Chemical Society)
      X-ray scintillators are widely used in medical imaging, industrial flaw detection, security inspection, and space exploration. However, traditional com. scintillators are usually assocd. with a high use cost because of their substantial toxicity and easy deliquescence. An atomically precise Au-Cu cluster scintillator (1) with a thermally activated delayed fluorescence (TADF) property was facilely synthesized, which is environmentally friendly and highly stable to H2O and O. The TADF property of 1 endows it with an ultrahigh exciton use rate. Combined with the effective absorption of x-ray caused by the heavy-atom effect and a limited nonradiative transition caused by close packing in the crystal state, 1 exhibits an excellent radioluminescence property. 1 has good processability for fabricating a large, flexible thin-film device (10 cm x 10 cm) for high-resoln. x-ray imaging, which can reach 40 μm (12.5 LP mm-1). The properties mentioned earlier make the coinage metal cluster promising for use as a substitute for traditional com. scintillators.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3sXht1Oms7rJ&md5=3aafaa552d3e2142d1e941e064ad36b9
    30. 30
      Li, Q.; Zhou, M.; So, W. Y.; Huang, J.; Li, M.; Kauffman, D. R.; Cotlet, M.; Higaki, T.; Peteanu, L. A.; Shao, Z.; Jin, R. A Mono-cuboctahedral Series of Gold Nanoclusters: Photoluminescence Origin, Large Enhancement, Wide Tunability, and Structure-Property Correlation. J. Am. Chem. Soc. 2019, 141, 5314– 5325,  DOI: 10.1021/jacs.8b13558
      30
      A Mono-cuboctahedral Series of Gold Nanoclusters: Photoluminescence Origin, Large Enhancement, Wide Tunability, and Structure-Property Correlation
      Li, Qi; Zhou, Meng; So, Woong Young; Huang, Jingchun; Li, Mingxing; Kauffman, Douglas R.; Cotlet, Mircea; Higaki, Tatsuya; Peteanu, Linda A.; Shao, Zhengzhong; Jin, Rongchao
      Journal of the American Chemical Society (2019), 141 (13), 5314-5325CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
      The origin of the near-IR photoluminescence (PL) from thiolate-protected gold nanoclusters (Au NCs, <2 nm) has long been controversial, and the exact mechanism for the enhancement of quantum yield (QY) in many works remains elusive. Meanwhile, based upon the sole steady-state PL anal., it is still a major challenge for researchers to map out a definitive relationship between the at. structure and the PL property and understand how the Au(0) kernel and Au(I)-S surface contribute to the PL of Au NCs. Herein, we provide a paradigm study to address the above crit. issues. By using a correlated series of "mono-cuboctahedral kernel" Au NCs and combined analyses of steady-state, temp.-dependence, femtosecond transient absorption, and Stark spectroscopy measurements, we have explicitly mapped out a kernel-origin mechanism and clearly elucidate the surface-structure effect, which establishes a definitive at.-level structure-emission relationship. A ∼100-fold enhancement of QY is realized via suppression of two effects: (i) the ultrafast kernel relaxation and (ii) the surface vibrations. The new insights into the PL origin, QY enhancement, wavelength tunability, and structure-property relationship constitute a major step toward the fundamental understanding and structural-tailoring-based modulation and enhancement of PL from Au NCs.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXkvVSls70%253D&md5=19c3d52052299e37ac2c51eae161fa10
    31. 31
      Zhou, M.; Du, X.; Wang, H.; Jin, R. The Critical Number of Gold Atoms for a Metallic State Nanocluster: Resolving a Decades-Long Question. ACS Nano 2021, 15, 13980– 13992,  DOI: 10.1021/acsnano.1c04705
      31
      The Critical Number of Gold Atoms for a Metallic State Nanocluster: Resolving a Decades-Long Question
      Zhou, Meng; Du, Xiangsha; Wang, He; Jin, Rongchao
      ACS Nano (2021), 15 (9), 13980-13992CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
      A review. Probing the transition from a metallic state to a mol. state in gold nanoparticles is fundamentally important for understanding the origin of surface plasmon resonance and the nature of the metallic bond. Atomically precise gold nanoclusters are desired for probing such a transition based upon a series of precise sizes with X-ray structures. While the definition of the metallic state in nanoclusters is simple, i.e., when the HOMO-LUMO gap (Eg) becomes negligibly small (Eg < kBT, where kB is the Boltzmann const. and T the temp.), the exptl. detn. of ultrasmall Eg (e.g., of kBT level) is difficult, and the thermal excitation of valence electrons apparently comes into play in ultrasmall Eg nanoclusters. Although a sharp transition from nonmetallic Au246(SR)80 to metallic Au279(SR)84 (SR: thiolate) has been obsd., there is still uncertainty about the transition region. Here, we summarize several criteria on detg. the metallic state vs. the mol. (or nonmetallic) state in gold nanoclusters, including (1) Eg detd. by optical and electrochem. methods, (2) steady-state absorption spectra, (3) cryogenic optical spectra, (4) transient absorption spectra, (5) excited-state lifetime and power dependence, and (6) coherent oscillations in ultrafast electron dynamics. We emphasize that multiple analyses should be performed and cross-checked in practice because no single criterion is definitive. We also review the photophysics of several gold nanoclusters with nascent surface plasmon resonance. These criteria are expected to deepen the understanding of the metallic to mol. state transition of gold and other metal nanoclusters and also promote the design of functional nanomaterials and their applications.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXhvFCqsLzM&md5=24be4adf9fc8778b393203f40096ae8b
    32. 32
      Kwak, K.; Thanthirige, V. D.; Pyo, K.; Lee, D.; Ramakrishna, G. Energy Gap Law for Exciton Dynamics in Gold Cluster Molecules. J. Phys. Chem. Lett. 2017, 8, 4898– 4905,  DOI: 10.1021/acs.jpclett.7b01892
      32
      Energy Gap Law for Exciton Dynamics in Gold Cluster Molecules
      Kwak, Kyuju; Thanthirige, Viraj Dhanushka; Pyo, Kyunglim; Lee, Dongil; Ramakrishna, Guda
      Journal of Physical Chemistry Letters (2017), 8 (19), 4898-4905CODEN: JPCLCD; ISSN:1948-7185. (American Chemical Society)
      The energy gap law relates the nonradiative decay rate to the energy gap sepg. the ground and excited states. Here the authors report that the energy gap law can be applied to exciton dynamics in Au cluster mols. Size-dependent electrochem. and optical properties were studied for n-hexanethiolate-protected Au clusters ranging from Au25 to Au333. Voltammetric studies reveal that the HOMO-LUMO (HOMO-LUMO) gaps of these clusters decrease with increasing cluster size. Combined femtosecond and nanosecond time-resolved transient absorption measurements show that the exciton lifetimes decrease with increasing cluster size. Comparison of the size-dependent exciton lifetimes with the HOMO-LUMO gaps shows that they are linearly correlated, demonstrating the energy gap law for excitons in these Au cluster mols.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhsFens7bJ&md5=388b7ce301f64fd437fc9cd9415756cc
    33. 33
      Li, Q.; Zhou, D.; Chai, J.; So, W. Y.; Cai, T.; Li, M.; Peteanu, L. A.; Chen, O.; Cotlet, M.; Wendy Gu, X.; Zhu, H.; Jin, R. Structural Distortion and Electron Redistribution in Dual-Emitting Gold Nanoclusters. Nat. Commun. 2020, 11, 2897,  DOI: 10.1038/s41467-020-16686-8
      33
      Structural distortion and electron redistribution in dual-emitting gold nanoclusters
      Li, Qi; Zhou, Dongming; Chai, Jinsong; So, Woong Young; Cai, Tong; Li, Mingxing; Peteanu, Linda A.; Chen, Ou; Cotlet, Mircea; Wendy Gu, X.; Zhu, Haiming; Jin, Rongchao
      Nature Communications (2020), 11 (1), 2897CODEN: NCAOBW; ISSN:2041-1723. (Nature Research)
      Abstr.: Deciphering the complicated excited-state process is crit. for the development of luminescent materials with controllable emissions in different applications. Here we report the emergence of a photo-induced structural distortion accompanied by an electron redistribution in a series of gold nanoclusters. Such unexpected slow process of excited-state transformation results in near-IR dual emission with extended photoluminescent lifetime. We demonstrate that this dual emission exhibits highly sensitive and ratiometric response to solvent polarity, viscosity, temp. and pressure. Thus, a versatile luminescent nano-sensor for multiple environmental parameters is developed based on this strategy. Furthermore, we fully unravel the at.-scale structural origin of this unexpected excited-state transformation, and demonstrate control over the transition dynamics by tailoring the bi-tetrahedral core structures of gold nanoclusters. Overall, this work provides a substantial advance in the excited-state phys. chem. of luminescent nanoclusters and a general strategy for the rational design of next-generation nano-probes, sensors and switches.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhtFGhsrnM&md5=28a6701e269aa913c950bff95583ae6d
    34. 34
      Fan, W.; Yang, Y.; You, Q.; Li, J.; Deng, H.; Yan, N.; Wu, Z. Size- and Shape-Dependent Photoexcitation Electron Transfer in Metal Nanoclusters. J. Phys. Chem. C 2023, 127, 816– 823,  DOI: 10.1021/acs.jpcc.2c07678
      There is no corresponding record for this reference.
    35. 35
      Wang, Y.; Liu, Z.; Mazumder, A.; Gianopoulos, C. G.; Kirschbaum, K.; Peteanu, L. A.; Jin, R. Tailoring Carbon Tails of Ligands on Au52(SR)32 Nanoclusters Enhances the Near-Infrared Photoluminescence Quantum Yield from 3.8 to 18.3%. J. Am. Chem. Soc. 2023, 145, 26328– 26338,  DOI: 10.1021/jacs.3c09846
      There is no corresponding record for this reference.
    36. 36
      Liu, Z.; Luo, L.; Kong, J.; Kahng, E.; Zhou, M.; Jin, R. Bright Near-Infrared Emission from the Au39(SR)29 Nanocluster. Nanoscale 2024, 16, 7419– 7426,  DOI: 10.1039/D4NR00677A
      There is no corresponding record for this reference.
    37. 37
      Pniakowska, A.; Kumaranchira Ramankutty, K.; Obstarczyk, P.; Peric Bakulic, M.; Sanader Marsic, Z.; Bonacic-Koutecky, V.; Burgi, T.; Olesiak-Banska, J. Gold-Doping Effect on Two-Photon Absorption and Luminescence of Atomically Precise Silver Ligated Nanoclusters. Angew. Chem., Int. Ed. 2022, 61, e202209645  DOI: 10.1002/anie.202209645
      37
      Gold-Doping Effect on Two-Photon Absorption and Luminescence of Atomically Precise Silver Ligated Nanoclusters
      Pniakowska, Anna; Kumaranchira Ramankutty, Krishnadas; Obstarczyk, Patryk; Peric Bakulic, Martina; Sanader Marsic, Zeljka; Bonacic-Koutecky, Vlasta; Buergi, Thomas; Olesiak-Banska, Joanna
      Angewandte Chemie, International Edition (2022), 61 (43), e202209645CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
      Noble metal nanoclusters allow for the atomically-precise control of their compn. However, to create nanoclusters with pre-defined optical properties, comprehensive description of their structure-property relation is required. Here, we report the gold atom doping impact on one-photon and two-photon absorption (TPA) and luminescence properties of ligated silver nanoclusters via combined exptl. studies and time-dependent d. functional theory simulations (TD-DFT). We synthesized a series of Ag25-xAux(DMBT)18 nanoclusters where x=0, 1 and 5-10. For Ag24Au1(DMBT)18 we demonstrate that the presence of the central Au dopant strongly influences linear and non-linear optical properties, increasing photoluminescence quantum yield and two-photon brightness, with respect to undoped silver nanoclusters. With improved TPA and luminescence, atomically-precise AuAg alloys presented in our work can serve as robust luminescent probes e.g. for bioimaging in the second biol. window.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38Xitl2ntLnP&md5=0b3f1660f9f0237a5540bbaa7b256a8d
    38. 38
      Li, Q.; Zeman, C. J. t.; Schatz, G. C.; Gu, X. W. Source of Bright Near-Infrared Luminescence in Gold Nanoclusters. ACS Nano 2021, 15, 16095– 16105,  DOI: 10.1021/acsnano.1c04759
      38
      Source of Bright Near-Infrared Luminescence in Gold Nanoclusters
      Li, Qi; Zeman, Charles J.; Schatz, George C.; Gu, X. Wendy
      ACS Nano (2021), 15 (10), 16095-16105CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
      Gold nanoclusters with near-IR (NIR) photoluminescence (PL) have great potential as sensing and imaging materials in biomedical and bioimaging applications. In this work, Au21(S-Adm)15 and Au38S2(S-Adm)20 are used to unravel the underlying mechanisms for the improved quantum yields (QY), large Stokes shifts, and long PL lifetimes in gold nanoclusters. Both nanoclusters show decent PL QY. In particular, the Au38S2(S-Adm)20 nanocluster shows a bright NIR PL at 900 nm with QY up to 15% in normal solvents (such as toluene) at ambient conditions. The relatively lower QY for Au21(S-Adm)15 (4%) compared to that of Au38S2(S-Adm)20 is attributed to the lowest-lying excited state being symmetry-disallowed, as evidenced by the pressure-dependent antispectral shift of the absorption spectra compared to PL, yet Au21(S-Adm)15 maintains some emissive properties due to a nearby symmetry-allowed excited state. Furthermore, our results show that suppression of nonradiative decay due to the surface "lock rings", which encircle the Au kernel and the surface "lock atoms" which bridge the fundamental Au kernel units (e.g., tetrahedra, icosahedra, etc.), is the key to obtaining high QYs in gold nanoclusters. The complicated excited-state processes and the small absorption coeff. of the band-edge transition lead to the large Stokes shifts and the long PL lifetimes that are widely obsd. in gold nanoclusters.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXitFOhtL3K&md5=91cca9762c861d40ff362fa9a4441a06
    39. 39
      Narouz, M. R.; Takano, S.; Lummis, P. A.; Levchenko, T. I.; Nazemi, A.; Kaappa, S.; Malola, S.; Yousefalizadeh, G.; Calhoun, L. A.; Stamplecoskie, K. G.; Hakkinen, H.; Tsukuda, T.; Crudden, C. M. Robust, Highly Luminescent Au13 Superatoms Protected by N-Heterocyclic Carbenes. J. Am. Chem. Soc. 2019, 141, 14997– 15002,  DOI: 10.1021/jacs.9b07854
      39
      Robust, Highly Luminescent Au13 Superatoms Protected by N-Heterocyclic Carbenes
      Narouz, Mina R.; Takano, Shinjiro; Lummis, Paul A.; Levchenko, Tetyana I.; Nazemi, Ali; Kaappa, Sami; Malola, Sami; Yousefalizadeh, Goonay; Calhoun, Larry A.; Stamplecoskie, Kevin G.; Hakkinen, Hannu; Tsukuda, Tatsuya; Crudden, Cathleen M.
      Journal of the American Chemical Society (2019), 141 (38), 14997-15002CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
      Au superatom nanoclusters stabilized entirely by N-heterocyclic carbenes (NHCs) and halides are reported. The redn. of well-defined NHC-Au-Cl complexes produces clusters comprised of an icosahedral Au13 core surrounded by a sym. arrangement of nine NHCs and three chlorides. X-ray crystallog. shows that the clusters were characterized by multiple CH-π and π-π interactions, which rigidify the ligand and likely contribute to the exceptionally high photoluminescent quantum yields obsd., up to 16.0%, which is significantly greater than that of the most luminescent ligand-protected Au13 superatom cluster. D. functional theory anal. suggests that clusters are 8-electron superatoms with a wide HOMO-LUMO energy gap of 2 eV. Consistent with this, the clusters have high stability relative to phosphine stabilized clusters.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhslegt7vP&md5=97e2ef250fb664f184d48b6a1963e718
    40. 40
      She, J.; Pei, W.; Zhou, S.; Zhao, J. Enhanced Fluorescence with Tunable Color in Doped Diphosphine-Protected Gold Nanoclusters. J. Phys. Chem. Lett. 2022, 13, 5873– 5880,  DOI: 10.1021/acs.jpclett.2c01522
      40
      Enhanced Fluorescence with Tunable Color in Doped Diphosphine-Protected Gold Nanoclusters
      She, Jie; Pei, Wei; Zhou, Si; Zhao, Jijun
      Journal of Physical Chemistry Letters (2022), 13 (25), 5873-5880CODEN: JPCLCD; ISSN:1948-7185. (American Chemical Society)
      Rational control of the luminescent properties of ligand-protected coinage metal clusters has long been pursued but remains challenging. Here we explore the crucial structural and electronic factors governing the fluorescence of a diphosphine-protected [Au13(dppe)5Cl2]3+ cluster by time-dependent d. functional theory calcns. By substituting the central Au atom with group 5 to group 11 transition metal atoms, the emission wavelength is adjustable from red to blue, accompanied by enhanced fluorescence intensity compared with the undoped cluster. The evolution of light-emitting behavior upon doping and the corresponding roles of the dopant, Au cage, ligands, and their interplay are interpreted at the electronic structure level. In particular, strong dopant-Au cage interaction assocd. with large electron-hole overlap on the dopant are is a key factor to endow large emission energy and intensity. These theor. results provide vital guidance for designing atomically precise nanoclusters with visible fluorescence and high quantum yield for practical uses.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XhsFCgt7bE&md5=d2ba604d98549244ea0cb6d793116d6a
    41. 41
      Takano, S.; Hirai, H.; Nakashima, T.; Iwasa, T.; Taketsugu, T.; Tsukuda, T. Photoluminescence of Doped Superatoms M@Au12 (M = Ru, Rh, Ir) Homoleptically Capped by (Ph2)PCH2P(Ph2): Efficient Room-Temperature Phosphorescence from Ru@Au12. J. Am. Chem. Soc. 2021, 143, 10560– 10564,  DOI: 10.1021/jacs.1c05019
      41
      Photoluminescence of Doped Superatoms M@Au12 (M = Ru, Rh, Ir) Homoleptically Capped by (Ph2)PCH2P(Ph2): Efficient Room-Temperature Phosphorescence from Ru@Au12
      Takano, Shinjiro; Hirai, Haru; Nakashima, Takuya; Iwasa, Takeshi; Taketsugu, Tetsuya; Tsukuda, Tatsuya
      Journal of the American Chemical Society (2021), 143 (28), 10560-10564CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
      A series of doped gold superatoms M@Au12 (M = Ru, Rh, Ir) was synthesized by capping with the bidentate ligand (Ph2)PCH2P(Ph2). A single-crystal X-ray diffraction anal. showed that all the M@Au12 superatoms had icosahedral motifs with a significantly higher symmetry than that of the pure Au13 counterpart due to different coordination geometries. The Ru@Au12 superatom exhibited a room-temp. phosphorescence with the highest quantum yield of 0.37 in deaerated dichloromethane. D. functional theory calcns. suggested that the efficient phosphorescence is ascribed to a rapid intersystem crossing due to the similarity between the singlet and triplet excited states in terms of structure and energy.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXhs1WmsLrO&md5=36127a9faabcc41773badb1b4841b1d4
    42. 42
      Chen, Y.; Zhou, M.; Li, Q.; Gronlund, H.; Jin, R. Isomerization-Induced Enhancement of Luminescence in Au28(SR)20 Nanoclusters. Chem. Sci. 2020, 11, 8176– 8183,  DOI: 10.1039/D0SC01270J
      42
      Isomerization-induced enhancement of luminescence in Au28(SR)20 nanoclusters
      Chen, Yuxiang; Zhou, Meng; Li, Qi; Gronlund, Harrison; Jin, Rongchao
      Chemical Science (2020), 11 (31), 8176-8183CODEN: CSHCCN; ISSN:2041-6520. (Royal Society of Chemistry)
      Understanding the origin and structural basis of the photoluminescence (PL) phenomenon in thiolate-protected metal nanoclusters is of paramount importance for both fundamental science and practical applications. It remains a major challenge to correlate the PL properties with the at.-level structure due to the complex interplay of the metal core (i.e. the inner kernel) and the exterior shell (i.e. surface Au(I)-thiolate staple motifs). Decoupling these two intertwined structural factors is crit. in order to understand the PL origin. Herein, we utilize two Au28(SR)20 nanoclusters with different -R groups, which possess the same core but different shell structures and thus provide an ideal system for the PL study. We discover that the Au28(CHT)20 (CHT: cyclohexanethiolate) nanocluster exhibits a more than 15-fold higher PL quantum yield than the Au28(TBBT)20 nanocluster (TBBT: p-tert-butylbenzenethiolate). Such an enhancement is found to originate from the different structural arrangement of the staple motifs in the shell, which modifies the electron relaxation dynamics in the inner core to different extents for the two nanoclusters. Overall, this work offers structural insights into the PL origin in Au28(SR)20 nanoclusters and provides some guidelines for designing luminescent metal nanoclusters for sensing and optoelectronic applications.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhsVSisLrF&md5=1332dbc4bcd3a52666059d07075077ef
    43. 43
      Deng, H.; Huang, K.; Xiu, L.; Sun, W.; Yao, Q.; Fang, X.; Huang, X.; Noreldeen, H. A. A.; Peng, H.; Xie, J.; Chen, W. Bis-Schiff Base Linkage-Triggered Highly Bright Luminescence of Gold Nanoclusters in Aqueous Solution at the Single-Cluster Level. Nat. Commun. 2022, 13, 3381,  DOI: 10.1038/s41467-022-30760-3
      43
      Bis-Schiff base linkage-triggered highly bright luminescence of gold nanoclusters in aqueous solution at the single-cluster level
      Deng, Haohua; Huang, Kaiyuan; Xiu, Lingfang; Sun, Weiming; Yao, Qiaofeng; Fang, Xiangyu; Huang, Xin; Noreldeen, Hamada A. A.; Peng, Huaping; Xie, Jianping; Chen, Wei
      Nature Communications (2022), 13 (1), 3381CODEN: NCAOBW; ISSN:2041-1723. (Nature Portfolio)
      Metal nanoclusters (NCs) have been developed as a new class of luminescent nanomaterials with potential applications in various fields. However, for most of the metal NCs reported so far, the relatively low photoluminescence quantum yield (QY) in aq. soln. hinders their applications. Here, we describe the utilization of bis-Schiff base linkages to restrict intramol. motion of surface motifs at the single-cluster level. Based on Au22(SG)18 (SG: glutathione) NCs, an intracluster crosslinking system was constructed with 2,6-pyridinedicarboxaldehyde (PDA), and water-sol. gold NCs with luminescence QY up to 48% were obtained. The proposed approach for achieving high emission efficiency can be extended to other luminescent gold NCs with core-shell structure. Our results also show that the content of surface-bound Au(I)-SG complexes has a significant impact on the PDA-induced luminescence enhancement, and a high ratio of Au(I)-SG will be beneficial to increasing the photoluminescence intensity of gold NCs.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XhsFGrtLvL&md5=fe2ececb4bf58943ac04afd4ca7cc010
    44. 44
      Wei, X.; Kang, X.; Jin, S.; Wang, S.; Zhu, M. Aggregation of Surface Structure Induced Photoluminescence Enhancement in Atomically Precise Nanoclusters. CCS Chem. 2021, 3, 1929– 1939,  DOI: 10.31635/ccschem.020.202000372
      There is no corresponding record for this reference.
    45. 45
      Jin, Y.; Zhang, C.; Dong, X. Y.; Zang, S. Q.; Mak, T. C. W. Shell Engineering to Achieve Modification and Assembly of Atomically-precise Silver Clusters. Chem. Soc. Rev. 2021, 50, 2297– 2319,  DOI: 10.1039/D0CS01393E
      45
      Shell engineering to achieve modification and assembly of atomically-precise silver clusters
      Jin, Yan; Zhang, Chong; Dong, Xi-Yan; Zang, Shuang-Quan; Mak, Thomas C. W.
      Chemical Society Reviews (2021), 50 (4), 2297-2319CODEN: CSRVBR; ISSN:0306-0012. (Royal Society of Chemistry)
      A review. Continuing research on the prepn. and structural detn. of monolayer-protected silver clusters has been performed. The compds. include mixed-valence Ag0/1+ clusters and single-valence Ag1+ clusters, which contain a few to tens or hundreds of Ag atoms that are protected by org. ligands. Sometimes, counter ions and extraneous species appear in their cryst. state. Atomically-precise structures help to map out definite electronic structures and structure-property correlations, enabling precise control of shell layers to achieve desired stability and specific functionalities. In this Tutorial Review, based on classic silver cluster paradigms, we first summarize the strategies and recent advances in precise modification and hierarchical assembly of well-defined silver clusters through shell engineering. Second, the correlations of structure-property and structure-functionality are summarized. Of these, the most important is structure-luminescence relationship, which is discussed in detail. In this topic, the uniqueness and prospect of silver clusters as potential lighting materials are scrutinized. Finally, the existing challenges and perspectives of functional silver clusters are presented. The general strategic design presented in this Review will motivate researchers to exploit the development of functionality-oriented materials based on nanosized building blocks in the enrichment of nanotechnol. and material science.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXht1aqtLY%253D&md5=8c113b0cbb52de6ec03eb2cb24432653
    46. 46
      Luo, L.; Liu, Z.; Du, X.; Jin, R. Near-Infrared Dual Emission from the Au42(SR)32 Nanocluster and Tailoring of Intersystem Crossing. J. Am. Chem. Soc. 2022, 144, 19243– 19247,  DOI: 10.1021/jacs.2c09107
      46
      Near-Infrared Dual Emission from the Au42(SR)32 Nanocluster and Tailoring of Intersystem Crossing
      Luo, Lianshun; Liu, Zhongyu; Du, Xiangsha; Jin, Rongchao
      Journal of the American Chemical Society (2022), 144 (42), 19243-19247CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
      This work presents the synthesis and intriguing photoluminescence of the Au42(PET)32 (PET = 2-phenylethanethiolate) nanocluster (NC). The Au42(PET)32 NC exhibits dual emission at 875 and 1040 nm, which are revealed to be fluorescence and phosphorescence, resp. The emission quantum yield (QY) of Au42(PET)32 in dichloromethane is 11.9% at room temp. in air, which is quite rare for thiolate-protected Au NCs. When Au42(PET)32 NCs are embedded in polystyrene films (solid state), the fluorescence was dramatically suppressed while the phosphorescence was significantly enhanced. This divergent behavior is explained by dipolar interaction-induced enhancement of intersystem crossing from singlet to triplet excited state.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38Xis1WltbjN&md5=4877de36eb8e307bcee4224a8293ef87
    47. 47
      Li, Y.; Song, Y.; Zhang, X.; Liu, T.; Xu, T.; Wang, H.; Jiang, D.-e.; Jin, R. Atomically Precise Au42 Nanorods with Longitudinal Excitons for an Intense Photothermal Effect. J. Am. Chem. Soc. 2022, 144, 12381– 12389,  DOI: 10.1021/jacs.2c03948
      47
      Atomically Precise Au42 Nanorods with Longitudinal Excitons for an Intense Photothermal Effect
      Li, Yingwei; Song, Yongbo; Zhang, Xinwen; Liu, Tongyu; Xu, Tingting; Wang, He; Jiang, De-en; Jin, Rongchao
      Journal of the American Chemical Society (2022), 144 (27), 12381-12389CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
      Atomically precise rod-shaped Au42(SCH2Ph)32 with a hcp. Au20 kernel of aspect ratio ≤6.2, which exhibits an intense absorption at 815 nm with a high molar absorptivity of 1.4 × 105 M-1 cm-1, are reported. Compared to other rod-shaped nanoclusters, Au42 possesses a much more effective photothermal conversion with a large temp. increase of ∼27° within 5 min (λex = 808 nm, 1 W cm-2) at an ultralow concn. of 50 μg mL-1 in toluene. D. functional theory calcns. show that the near-IR transition is mainly along the long axis of the Au20 kernel in Au42, i.e., a longitudinal excitonic oscillation, akin to the longitudinal plasmon in metallic-state nanorods. Transient absorption spectroscopy reveals that the fast decay in Au42 is similar to that of shorter-aspect-ratio nanorods but is followed by an addnl. slow decay with a long lifetime of 2400 ns for the Au42 nanorod.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38Xhs1Whu7vO&md5=f939f133acd28be6d9a5ffda4469b4a7
    48. 48
      Luo, L.; Liu, Z.; Kong, J.; Gianopoulos, C. G.; Coburn, I.; Kirschbaum, K.; Zhou, M.; Jin, R. Three-Atom-Wide Gold Quantum Rods with Periodic Elongation and Strongly Polarized Excitons. Proc. Natl. Acad. Sci. U S A 2024, 121, e2318537121  DOI: 10.1073/pnas.2318537121
      There is no corresponding record for this reference.
    49. 49
      Liu, Z.; Li, Y.; Shin, W.; Jin, R. Observation of Core Phonon in Electron-Phonon Coupling in Au25 Nanoclusters. J. Phys. Chem. Lett. 2021, 12, 1690– 1695,  DOI: 10.1021/acs.jpclett.1c00050
      49
      Observation of Core Phonon in Electron-Phonon Coupling in Au25 Nanoclusters
      Liu, Zhongyu; Li, Yingwei; Shin, Wonyong; Jin, Rongchao
      Journal of Physical Chemistry Letters (2021), 12 (6), 1690-1695CODEN: JPCLCD; ISSN:1948-7185. (American Chemical Society)
      Temp.-dependent optical properties are of paramount importance for fundamentally understanding the electron-phonon interactions and phonon modes in atomically precise nanocluster materials. In this work, low-temp. optical absorption spectra of the icosahedral [Au25(SR)18]- nanocluster are measured from room temp. down to liq. helium temp. by adopting a thin-film-based technique. The thin-film measurement is further compared with results from the previous soln.-based method. Interestingly, the previously missing core phonon is revealed by a quant. anal. of the film data through peak deconvolution and fitting of the temp. trend with a theor. model. The two lowest-energy absorption peaks (at 1.6 and 1.8 eV) of Au25 are detd. to couple with the staple-shell phonon (av. energy ~ 350 cm-1) in the soln. state, but in the solid state these electronic transitions couple with the core phonon (av. energy ~ 180 cm-1). The suppression of the staple-shell phonon in the solid state is attributed to the intracluster and cluster-matrix interactions.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3MXjsVSlsLk%253D&md5=95c63fd7a7dcb4611e8c9fa88e94b062
    50. 50
      Steele, J. A.; Puech, P.; Monserrat, B.; Wu, B.; Yang, R. X.; Kirchartz, T.; Yuan, H.; Fleury, G.; Giovanni, D.; Fron, E.; Keshavarz, M.; Debroye, E.; Zhou, G.; Sum, T. C.; Walsh, A.; Hofkens, J.; Roeffaers, M. B. J. Role of Electron-Phonon Coupling in the Thermal Evolution of Bulk Rashba-Like Spin-Split Lead Halide Perovskites Exhibiting Dual-Band Photoluminescence. ACS Energy Lett. 2019, 4, 2205– 2212,  DOI: 10.1021/acsenergylett.9b01427
      50
      Role of Electron-Phonon Coupling in the Thermal Evolution of Bulk Rashba-Like Spin-Split Lead Halide Perovskites Exhibiting Dual-Band Photoluminescence
      Steele, Julian A.; Puech, Pascal; Monserrat, Bartomeu; Wu, Bo; Yang, Ruo Xi; Kirchartz, Thomas; Yuan, Haifeng; Fleury, Guillaume; Giovanni, David; Fron, Eduard; Keshavarz, Masoumeh; Debroye, Elke; Zhou, Guofu; Sum, Tze Chien; Walsh, Aron; Hofkens, Johan; Roeffaers, Maarten B. J.
      ACS Energy Letters (2019), 4 (9), 2205-2212CODEN: AELCCP; ISSN:2380-8195. (American Chemical Society)
      The optoelectronic properties of lead halide perovskites strongly depend on their underlying crystal symmetries and dynamics, sometimes exhibiting a dual photoluminescence (PL) emission via Rashba-like effects. Here we exploit spin- and temp.-dependent PL to study single-crystal APbBr3 (A = Cs and methylammonium; CH3NH3) and evaluate the peak energy, intensity, and line width evolutions of their dual emission. Both perovskites exhibit temp. trends governed by two temp. regimes-above and below approx. 100 K-which impose different carrier scattering and radiative recombination dynamics. With increasing temp., high-energy optical phonons activate near 100 K to drive energy splitting of the dual bands and induce line width broadening via electron-phonon coupling, with a stronger coupling const. inferred for carriers recombining by the spin-split indirect bands, compared to the direct ones. We find that the unusual thermal evolutions of all-inorg. and hybrid bulk lead bromide perovskites are comparable, suggesting A-site independence and the dominance of dynamic effects, and are best understood within a framework that accounts for Rashba-like effects.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXhsF2rs77F&md5=e56578c05dc54f6953135342afcab0fd

  • Supporting Information

    Supporting Information

    The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/jacs.4c11703.

    • Details of the synthesis and data analysis and additioanl figures and tables as described in the text (PDF)


    Terms & Conditions

    Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.

back