Li Hui-Miao, Zhong Gui-Ming, Wu Shu-Qi, Sato Osamu, Zheng Xiao-Yan, Yao Zi-Shuo, Tao Jun
Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, People's Republic of China.
CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, Fujian, China.
Inorg Chem. 2021 Jun 7;60(11):8042-8048. doi: 10.1021/acs.inorgchem.1c00558. Epub 2021 May 26.
Many crystalline molecular rotors have been developed in the past decades. However, manipulating the rotational gesture that intrinsically controls the physical performance of materials remains a challenge. Herein, we report a series of crystalline rotors whose rotational gestures can be modulated by modifying the structures of molecular stators. In these dynamic crystals, the ox (ox = oxalate anion) behave as molecular rotators performing axial-free rotation in cavities composed of five complex cations, [M(en)] (en = ethylenediamine). The structure of [M(en)] that serves as a molecular stator can be tuned by varying the metal center with different ionic radii, consequently altering the chemical environment around the molecular rotator. Owing to the quasi-transverse isotropy of ox and multiple hydrogen-bond interactions around it, the molecular rotator exhibits unusual motional malleability, i.e., it can rotate either longitudinally in the compound of Zn, or with a tilt angle of 42° in the compound of Fe, or even laterally in the compound of Cd. The atypical dynamic behavior demonstrated here provides a new chance for the development of exquisite crystalline molecular rotors with advanced tunable functionalities.
在过去几十年中，人们已经开发出了许多晶体分子转子。然而，控制本质上决定材料物理性能的旋转姿态仍然是一个挑战。在此，我们报道了一系列晶体转子，其旋转姿态可通过修饰分子定子的结构来调节。在这些动态晶体中，草酸根阴离子（ox = 草酸根阴离子）充当分子转子，在由五个络合阳离子[M(en)]（en = 乙二胺）组成的空腔中进行无轴向旋转。作为分子定子的[M(en)]的结构可以通过改变具有不同离子半径的金属中心来调节，从而改变分子转子周围的化学环境。由于草酸根阴离子的准横向各向同性及其周围的多重氢键相互作用，分子转子表现出不同寻常的运动可塑性，即它可以在锌化合物中纵向旋转，在铁化合物中以42°的倾斜角旋转，甚至在镉化合物中横向旋转。这里展示的非典型动态行为为开发具有先进可调功能的精致晶体分子转子提供了新的机会。
