Hua Xiu-Ni, Gao Ji-Xing, Chen Xiao-Gang, Li Peng-Fei, Mei Guang-Quan, Liao Wei-Qiang
Jiangsu Key Laboratory for Science and Applications of Molecular Ferroelectrics, Southeast University, Nanjing 211189, P. R. China.
Dalton Trans. 2019 May 15;48(19):6621-6626. doi: 10.1039/c9dt00945k.
A novel organic-inorganic ABX3 perovskite-type material with specific hydrogen bonding interactions, N,N-dimethylethanolammonium trichlorocadmate ([DMEA]CdCl3), has been synthesized as a phase transition material. It is notable that the DMEA cations are arranged to form one-dimensional chains connected by hydrogen bonds at room temperature, which are very sparse in other perovskite-type compounds. The strong intermolecular interactions have made the phase transition temperature of the material reach up to 429 K, as confirmed by differential scanning calorimetry measurements, variable-temperature structural analyses, and dielectric measurements. The origin of the symmetry-breaking phase transition is associated with the motion or reorientation of the DMEA cations, accompanied by the crystal structures from orthorhombic Pnma to monoclinic P21/c with the temperature decreases. The finding of [DMEA]CdCl3 with unprecedented hydrogen bonding interactions has opened a new avenue to design novel phase transition materials with higher transition temperatures.
一种具有特定氢键相互作用的新型有机-无机ABX3钙钛矿型材料，N,N-二甲基乙醇铵三氯镉酸盐([DMEA]CdCl3)，已被合成作为一种相变材料。值得注意的是，在室温下，DMEA阳离子排列形成通过氢键连接的一维链，这在其他钙钛矿型化合物中非常稀少。通过差示扫描量热法测量、变温结构分析和介电测量证实，强分子间相互作用使该材料的相变温度高达429K。对称性破缺相变的起源与DMEA阳离子的运动或重新取向有关，随着温度降低，晶体结构从正交Pnma转变为单斜P21/c。具有前所未有的氢键相互作用的[DMEA]CdCl3的发现为设计具有更高转变温度的新型相变材料开辟了一条新途径。
