Omoto Kenichiro, Nakae Toyotaka, Nishio Masaki, Yamanoi Yoshinori, Kasai Hidetaka, Nishibori Eiji, Mashimo Takaki, Seki Tomohiro, Ito Hajime, Nakamura Kazuki, Kobayashi Norihisa, Nakayama Naofumi, Goto Hitoshi, Nishihara Hiroshi
Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Division of Materials Science, Nara Institute of Science and Technology (NAIST), 8916-5 Takayama-cho, Ikoma 630-0192, Japan.
J Am Chem Soc. 2020 Jul 22;142(29):12651-12657. doi: 10.1021/jacs.0c03643. Epub 2020 Jul 7.
We describe here the preparation of soft crystals using disilanyl macrocycle possessing four -phenylenes circularly connected by four flexible disilane bonds. Single crystals of exhibited a reversible thermal single-crystal-to-single-crystal (SCSC) phase transition behavior between two crystal phases accompanied by remarkable mechanical motion (thermosalient effect), as revealed by thermal analyses and X-ray diffraction measurements. Detailed structural analyses implied that flexibility of the parallelogram disilanyl architecture and molecular packing mode via weak intermolecular interactions facilitated a concerted structural transformation (parallel crank motion) of macrocycles in the crystal, thus resulting in the SCSC phase transition accompanied by anisotropic shrinking/elongation of the cells to induce the thermosalient effect. This work explores a new area of organosilicon chemistry and presents the potential utility of disilanyl macrocycles as soft crystals.
我们在此描述了使用由四个柔性乙硅烷键环形连接的四个亚苯基的乙硅烷基大环制备软晶体的方法。热分析和X射线衍射测量表明，单晶在两个晶相之间表现出可逆的热单晶到单晶（SCSC）相变行为，并伴有显著的机械运动（热致突变效应）。详细的结构分析表明，平行四边形乙硅烷基结构的柔韧性以及通过弱分子间相互作用的分子堆积模式促进了晶体中大环的协同结构转变（平行曲柄运动），从而导致SCSC相变，并伴随着晶胞的各向异性收缩/伸长，进而引发热致突变效应。这项工作探索了有机硅化学的一个新领域，并展示了乙硅烷基大环作为软晶体的潜在用途。
