Kuno Jumpei, Imamura Yutaka, Katouda Michio, Tashiro Motomichi, Kawai Tsuyoshi, Nakashima Takuya
Division of Materials Science, Nara Institute of Science and Technology (NAIST), 8916-5 Takayama, Ikoma, Nara, 630-0192, Japan.
Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji, Tokyo, 192-0397, Japan.
Angew Chem Int Ed Engl. 2018 Sep 10;57(37):12022-12026. doi: 10.1002/anie.201807191. Epub 2018 Aug 21.
Optical activity in inorganic colloidal materials was controlled through interactions of chiral molecules with the nanoparticle (NP) surface. An inversion of optical activity in the synthesis of mercury sulfide (HgS) NPs was demonstrated with an intrinsically chiral crystalline system in the presence of an identical chiral capping ligand. A continuous decrease in the positive first Cotton effect and an eventual reversal of CD profile were observed upon heating the aqueous solution of HgS NPs capped with N-acetyl-l-cysteine (Ac-l-Cys) at 80 °C. Ac-l-Cys afforded two bidentate coordination configurations with an almost mirror image of each other using the thiolate and either of carboxylate or acetyl-carbonyl groups on the HgS core. Experiment and calculation suggest that a shift in the distribution of the NP formation with energy in response to the combinations of ligand coordination structure and chiral crystalline surface is responsible for the inversion of optical activity.
通过手性分子与纳米颗粒（NP）表面的相互作用来控制无机胶体材料中的光学活性。在相同手性封端配体存在的情况下，利用本征手性晶体系统证明了硫化汞（HgS）纳米颗粒合成过程中光学活性的反转。在80°C下加热用N-乙酰基-L-半胱氨酸（Ac-L-Cys）封端的HgS纳米颗粒水溶液时，观察到正的第一科顿效应持续降低，最终圆二色性（CD）谱反转。Ac-L-Cys利用硫醇盐以及HgS核上的羧酸盐或乙酰羰基中的任一个，提供了两种几乎彼此镜像的双齿配位构型。实验和计算表明，响应于配体配位结构和手性晶体表面的组合，NP形成的能量分布发生变化是光学活性反转的原因。
