无机-有机杂化化合物[（H2DABCO）CuCl4]·H2O的合成及开关型介电性质

Synthesis and Switchable Dielectric Properties of an Inorganic-organic Hybrid Complex [H2（ DABCO） CuCl4]·H2O

将1,4-二氮杂二环[2.2.2]辛烷(DABCO)、二水合氯化铜和盐酸溶于甲醇⁃水混合溶剂中,通过常温蒸发法制备了一个新颖的无机⁃有机杂化化合物[(H2DABCO)CuCl4]·H2O(1).利用红外光谱(IR)、X射线粉末衍射(XRD)、单晶X射线衍射、元素分析、热重分析(TG)、变温⁃变频介电分析等对化合物1进行结构表征及性质测试.在低温(100 K)和室温(294 K)下,该化合物属于单斜晶系P21/c空间群,在bc平面内,通过N—H…O,O—H…Cl等氢键自组装作用形成二维网状结构.而铜离子在c轴上的相对位移导致化合物1在多轴方向呈现出明显的开关型介电异常峰,变温⁃变频介电常数沿不同晶轴呈显著的各向异性.

A novel inorganic-organic hybrid complex,[H2(DABCO)CuCl4]·H2O(1),was successfully synthesized via the reaction of 1,4-diazabicyclo[2.2.2]octane,copper(Ⅱ)chloride dihydrate and hydrochloric acid.The complex was characterized by single-crystal X-ray diffraction,IR spectra,powder X-ray diffraction analysis,thermogravimetric analysis and variable-temperature dielectric measurement.Single crystal XRD analysis reveals that compound 1 belongs to monoclinic space group P21/c at low temperature and room temperature,and the unit cell parameters a,b,c,and V change significantly from low temperature to room temperature for the same structure phase transition.The single crystal structure shows that a two-dimensional network is formed in the bc plane through N—H…O and O—H…Cl hydrogen bonding interactions.The relative displacement of copper ions along the c-axis leads to switchable dielectric abnormal peaks and temperature dependence of its dielectric permittivity displays remarkable dielectric anisotropy along different crystal axes.