Department of Chemistry and Centre for Atomic Engineering of Advanced Materials, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology and Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, Anhui University, Hefei, Anhui 230601, China.
Key Laboratory of Optoelectronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, Hefei, Anhui 230601, China.
J Am Chem Soc. 2022 Mar 23;144(11):4845-4852. doi: 10.1021/jacs.1c12352. Epub 2022 Feb 15.
Accomplishing optical activity in materials has long been a challenge. Achiral nanomaterials that crystallize in achiral point groups are generally optically inactive. Herein we report the surprising observation of optical activity in several achiral point groups for supercrystals assembled from anisotropic metal nanoclusters with atomic precision. By analyzing multiple achiral nanoclusters with different molecular structures and symmetry space groups, we have identified that the molecular anisotropy of nanocluster entities and their asymmetric arrangement in point groups of supercrystals are the two key factors for the realization of optical activity in such supercrystals. We have further exploited the polarization effect of the nanocluster supercrystals as a polarization switch that can alter the polarized state of the linearly polarized light. Our findings have broadened the fundamental principles for producing nanomaterial-based optical activity and devices with polarization effects.
在材料中实现旋光性一直是一个挑战。手性点群中结晶的非手性纳米材料通常是无光活性的。本文报道了一个令人惊讶的现象，即由各向异性金属纳米团簇以原子精度组装而成的超晶体在几个非手性点群中表现出光活性。通过分析具有不同分子结构和对称空间群的多个非手性纳米团簇，我们已经确定纳米团簇实体的分子各向异性及其在超晶体点群中的不对称排列是非手性超晶体实现光活性的两个关键因素。我们进一步利用纳米团簇超晶体的偏振效应作为偏振开关，它可以改变线偏振光的偏振态。我们的发现拓宽了产生基于纳米材料的光活性和具有偏振效应的器件的基本原则。
