高低介电态的电学双稳态分子基杂化相变材料的合成与性质

摘要

为了制备一种新型高低介电态的电学双稳态分子基杂化相变材料，采用水热法合成了具有青铅矿拓扑结构的相变化合物[HN（CH2）6 NH][CdCl2（SO4）]（1）。通过变温 X 射线单晶结构测定法、差式扫描量热法（DSC）及变温介电测量法对其结构和性质进行了表征和研究。介电测量和 DSC 分析结果表明化合物1发生了二级可逆相变。单晶结构解析表明，硫酸根四面体中2个氧原子的无序性造成 SO－4四面体的摇摆运动和双质子化1，4—二氮杂二环[2．2．2]辛烷（DABCO）的运动，这些结构变化即为产生电学双稳态的室温相变的驱动力。化合物1的合成为高低介电态的电学双稳态分子基杂化相变材料的合成提供了一个新的途径。%A new molecular-hybridized dielectric material [HN(CH2 )6 NH][CdCl2 (SO4 )](1)with electrical bistability,has been synthesized under hydrothermal condition.Compound 1 is a phase transition material-cadmium sulfates of linerate topology.It has been characterized by variable-temperature X-ray single-crystal diffraction analysis,DSC and temperature-dependent dielectric measurement.Dielectric measurement and DSC results reveal that it has undergone a reversible second-order phase transition. X-ray single-crystal analysis shows that the disorder of two O atoms from SO-4 tetrahedron contributes to the swaying of SO-4 tet-rahedron and the motion of diprotonated DABCO cations,which is the driving force for the room-temperature phase transition. This novel design of the intelligent information processing materials between high and low dielectric states will open a new avenue for the synthesis of this type of materials.