中山大学张伟雄团队报道了新型有机-无机杂化后钙钛矿（N，N-二甲基吡咯烷鎓）[Mn(N(CN)₂)₃]的结构相变。相关研究成果于2024年2月29日发表在国际知名学术期刊《结构化学》。

在分子相变研究领域，特别是在传感器、数据存储和开关技术中的应用领域，有机-无机杂化钙钛矿材料的作用因其巨大的潜力而日益得到认可。然而，杂化后钙钛矿作为钙钛矿的一个关键亚类，尚未得到彻底的研究，主要局限于基于多原子桥接剂如二氰胺（dca）和非环状有机阳离子的情况。

该文中，研究人员使用极性环状季铵阳离子N，N-二甲基吡咯烷鎓（DMP+），来组装新的杂化后钙钛矿（DMP）[Mn（dca）3]（1），其在249K下经历从正交Bmmb到单斜P21/N空间基的相变，介电测量和Hirshfeld表面分析揭示了极性环状季铵DMP+在将相变温度提高48K、产生显著的介电开关效应，和促进无机框架的层间滑动方面的作用。

附：英文原文

Title: Structural phase transition in a new organic-inorganic hybrid post-perovskite: (N,N-dimethylpyrrolidinium)[Mn(N(CN)2)3]

Author: Le Ye, Wei-Xiong Zhang

Issue&Volume: 2024-02-29

Abstract: In the realm of molecular phase transition research, particularly for applications in sensors, data storage, and switching technologies, the role of organic-inorganic hybrid perovskite materials has been increasingly recognized for their significant potential. Nevertheless, hybrid post-perovskites, as a critical subclass of perovskites, has not been thoroughly studied and mainly limits in the instances based on polyatomic bridging agents like dicyanamide (dca) and non-cyclic organic cations. Herein, a polar cyclic quaternary ammonium cation, N,N-dimethylpyrrolidinium (DMP+), was used to assemble a new hybrid post-perovskite, (DMP)[Mn(dca)3] (1), which undergoes a phase transition from orthorhombic Bmmb to monoclinic P21/n space group at 249 K. By employing multiple techniques such as differential scanning calorimetry, variable-temperature single-crystal X-ray analysis, dielectric measurements, and Hirshfeld surface analysis, we disclosed the role of polar cyclic quaternary ammonium DMP+ in elevating the phase-transition temperature by 48 K, generating significant dielectric switching effect, and facilitating interlayer sliding of inorganic framework.

DOI: 10.1016/j.cjsc.2024.100257

Source: http://cjsc.ac.cn/cms/issues/575