School of Materials Science and Engineering, Center for Micro and Nanotechnology, Harbin Institute of Technology, Harbin, 150001, P. R. China.
CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China.
Angew Chem Int Ed Engl. 2017 Nov 27;56(48):15397-15401. doi: 10.1002/anie.201709827. Epub 2017 Nov 2.
Self-assembly of inorganic nanoparticles into ordered structures is of interest in both science and technology because it is expected to generate new properties through collective behavior; however, such nanoparticle assemblies with characteristics distinct from those of individual building blocks are rare. Herein we use atomically precise Au clusters to make ordered assemblies with emerging optical activity. Chiral Au clusters with strong circular dichroism (CD) but free of circularly polarized luminescence (CPL) are synthesized and organized into uniform body-centered cubic (BCC) packing nanocubes. Once the ordered structure is formed, the CD intensity is significantly enhanced and a remarkable CPL response appears. Both experiment and theory calculation disclose that the CPL originates from restricted intramolecular rotation and the ordered stacking of the chiral stabilizers, which are fastened in the crystalline lattices.
无机纳米粒子自组装成有序结构在科学和技术中都很有意义，因为它有望通过集体行为产生新的性质；然而，具有不同于单个构建块特性的此类纳米粒子组装体却很少见。在此，我们使用原子精确的 Au 团簇来制造具有新兴光学活性的有序组装体。合成了具有强圆二色性（CD）但无圆偏振发光（CPL）的手性 Au 团簇，并将其组织成均匀的体心立方（BCC） packing 纳米立方体。一旦形成有序结构，CD 强度就会显著增强，并且会出现显著的 CPL 响应。实验和理论计算都揭示了 CPL 源于受限的分子内旋转和手性稳定剂的有序堆积，它们被固定在晶格中。
