Chiral ligand-protected gold nanoclusters: Considering the optical activity from a viewpoint of ligand dissymmetric field
Chiral ligand-protected gold nanoclusters: Considering the optical activity from a viewpoint of ligand dissymmetric field
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DOI：
10.1016/j.pnsc.2016.08.006
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发表时间：
2016-10
期刊：
影响因子：
--
通讯作者：
H. Yao
中科院分区：
文献类型：
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作者：
H. Yao
手性是物理、化学或生物物体的几何特性，不能叠加在其镜像上。它的重要存在导致了对手性药物、传感器、催化剂和光功能材料开发的强烈需求。近年来，由于手性纳米技术的潜在应用，纳米级有机/无机杂化物的手性受到了极大的关注。特别是，随着受非手性硫醇盐保护的原子级精确金纳米团簇的合成和表征的最新进展，其手性的原子水平起源已经被揭示。另一方面，金属纳米团簇中的手性或光学活性也可以通过表面手性配体引入，这对于纳米系统来说应该是通用的。本教程综述介绍了一些受手性硫醇盐或膦保护的光学活性金属（金）纳米团簇，并且主要从配体不对称场方案的角度讨论了它们的手性（或圆二色性；CD）特性。例子是由(R)-/(S)-2-苯基丙烷-1-硫醇、(R)-/(S)-巯基琥珀酸、苯基硼酸-D/L-果糖复合物、膦磺酸盐-麻黄鎓离子对或谷胱甘肽保护的金纳米簇。还描述了纳米簇化合物的通用不对称变换和手性光学控制的一些方法。在作为光学活性起源的不对称场模型中，金纳米团簇的手性光学响应与耦合振荡器和/或基于微扰理论衍生的诱导CD（ICD）概念的CD窃取机制密切相关，因此在此基础上，详细介绍了观察到的手性配体保护的金纳米团簇CD响应的一些特征。我们相信，在配体保护的金纳米团簇中发现的各种手性起源可能为理解许多相关纳米材料的手性起源提供模型。
Chirality is a geometric property of a physical, chemical, or biological object, which is not superimposable on its mirror image. Its significant presence has led to a strong demand in the development of chiral drugs, sensors, catalysts, and photofunctional materials. In recent years, chirality of nanoscale organic/inorganic hybrids has received tremendous attention owing to potential applications in chiral nanotechnology. In particular, with the recent progress in the syntheses and characterizations of atomically precise gold nanoclusters protected byachiralthiolates, atomic level origins of their chirality have been unveiled. On the other hand, chirality or optical activity in metal nanoclusters can also be introduced via the surfacechiralligands, which should be universal for the nanosystems. This tutorial review presents some optically-active metal (gold) nanoclusters protected by chiral thiolates or phosphines, and their chiroptical (or circular dichroism; CD) properties are discussed mostly from a viewpoint of the ligand dissymmetric field scheme. The examples are the gold nanoclusters protected by (R)-/(S)-2-phenylpropane-1-thiol, (R)-/(S)-mercaptosuccinic acid, phenylboronate-D/L-fructose complexes, phosphine sulfonate-ephedrinium ion pairs, or glutathione. Some methodologies for versatile asymmetric transformation and chiroptical controls of the nanocluster compounds are also described. In the dissymmetric field model as the origin of optical activity, the chiroptical responses of the gold nanoclusters are strongly associated with coupled oscillator and/or CD stealing mechanisms based on the concept of induced CD (ICD) derived from a perturbation theory, so on this basis, some characteristic features of the observed CD responses of chiral ligand-protected gold nanoclusters are presented in detail. We believe that various kinds of origins of chirality found in ligand-protected gold nanoclusters may provide models for understanding those of many related nanomaterials.