Crystal Structure and Phase Transitions of a Novel Crown Ether Clathrate [(2-Thienylmethylamine)(18-crown-6)]2[Cd2Cl6]

Structural phase transition materials, such as ferroelectrics, piezoelectrics, and dielectric switches, have important application prospects in the field of multifunctional molecular materials. Crown ether, with its unique structure, is favored in the design and synthesis of many materials. However, crown ether clathrates (CECs) tend to exhibit lower phase transition temperatures, which greatly limits their application prospects in related fields. The design and synthesis of high-temperature phase change CECs have great challenges, and the related research has attracted wide attention. Here, a novel CEC [(C4H3S–CH2NH3)(18-crown-6)]2[Cd2Cl6](1) was successfully constructed. The single crystal structure, thermogravimetric, differential scanning calorimetry, variable temperature powder diffraction, dielectric and other properties of 1 were characterized and analyzed. 1 crystallizes at C2/c at 293 K and exhibits two step reversible phase transitions at near 414 and 430 K. The related research results provide a new idea for the design of high temperature phase change crown ether inclusions.