Assembling an alkyl rotor to access abrupt and reversible crystalline deformation of a cobalt(II) complex

作者：Su Sheng Qun; Kamachi Takashi; Yao Zi Shuo; Huang You Gui; Shiota Yoshihito; Yoshizawa Kazunari; Azuma Nobuaki; Miyazaki Yuji; Nakano Motohiro; Maruta Goro; Takeda Sadamu; Kang Soonchul; Kanegawa Shinji; Sato Osamu^*

来源：Nature Communications, 2015, 6(1): 8810.

DOI：10.1038/ncomms9810

Harnessing molecular motion to reversibly control macroscopic properties, such as shape and size, is a fascinating and challenging subject in materials science. Here we design a crystalline cobalt(II) complex with an n-butyl group on its ligands, which exhibits a reversible crystal deformation at a structural phase transition temperature. In the low-temperature phase, the molecular motion of the n-butyl group freezes. On heating, the n-butyl group rotates ca. 100 degrees around the C-C bond resulting in 6-7% expansion of the crystal size along the molecular packing direction. Importantly, crystal deformation is repeatedly observed without breaking the single-crystal state even though the shape change is considerable. Detailed structural analysis allows us to elucidate the underlying mechanism of this deformation. This work may mark a step towards converting the alkyl rotation to the macroscopic deformation in crystalline solids.

• 出版日期2015-11