Wu Cong, Gao Kai-Ge, Yao Zi-Shuo, Tao Jun
Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Liangxiang Campus, Beijing Institute of Technology, Beijing 102488, People's Republic of China.
College of Physical Science and Technology, Yangzhou University, Yangzhou, Jiangsu, People's Republic of China.
Dalton Trans. 2022 May 3;51(17):6809-6816. doi: 10.1039/d2dt00506a.
A series of dynamic single crystals with a chemical formula of [M(en)]SO (en = ethylene and M = Ni, Mn, and Cd) was synthesized. As the temperature decreases, these materials exhibit dielectric switching in the vicinity of the phase transition point accompanied by anisotropic thermal expansion in the cell parameters as a consequence of the order-disorder structural change of SO2-4 in a cavity surrounded by five [M(en)] complex cations. Because the variation of metal centers with different ionic radii changes the shape of the complex cation, which affects the distribution of hydrogen-bond interactions around the SO2-4, the dynamic motion of SO2-4 is substantially tuned. Correspondingly, the dielectric properties and anisotropic thermal expansion of materials were largely shifted, especially in the single crystals of [Mn(en)]SO, whose structural change is distinctly different from the crystals of Ni(II) and Cd(II). The detailed structural mechanism accounting for the different physical properties of these materials was discussed.
