Zhang Jing, Liu Xitao, Li Xianfeng, Han Shiguo, Tao Kewen, Wang Yuyin, Ji Chengmin, Sun Zhihua, Luo Junhua
Fuzhou University, No. 2 College Road, University New District, Fuzhou, Fujian, 350108, P.R. China.
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences 155, Yangqiao Road West, Fuzhou, Fujian, 350002, P.R. China.
Chem Asian J. 2018 Apr 16;13(8):982-988. doi: 10.1002/asia.201701588. Epub 2018 Mar 15.
Organic-inorganic hybrid perovskites, with the formula ABX (A=organic cation, B=metal cation, and X=halide; for example, CH NH PbI ), have diverse and intriguing physical properties, such as semiconduction, phase transitions, and optical properties. Herein, a new ABX -type semiconducting perovskite-like hybrid, (hexamethyleneimine)PbBr (1), consisting of one-dimensional inorganic frameworks and cyclic organic cations, is reported. Notably, the inorganic moiety of 1 adopts a perovskite-like architecture and forms infinite columns composed of face-sharing PbBr octahedra. Strikingly, the organic cation exhibits a highly flexible molecular configuration, which triggers an above-room-temperature phase transition, at T =338.8 K; this is confirmed by differential scanning calorimetry (DSC), specific heat capacity (C ), and dielectric measurements. Further structural analysis reveals that the phase transition originates from the molecular configurational distortion of the organic cations coupled with small-angle reorientation of the PbBr octahedra inside the inorganic components. Moreover, temperature-dependent conductivity and UV/Vis absorption measurements reveal that 1 also displays semiconducting behavior below T . It is believed that this work will pave a potential way to design multifeatured perovskite hybrids by utilizing cyclic organic amines.
具有ABX₃化学式（A =有机阳离子，B =金属阳离子，X =卤化物；例如，CH₃NH₃PbI₃）的有机-无机杂化钙钛矿具有多种引人入胜的物理性质，如半导体性质、相变和光学性质。在此，报道了一种新型的ABX₃型类半导体钙钛矿杂化材料（六亚甲基亚胺）PbBr₃（1），它由一维无机骨架和环状有机阳离子组成。值得注意的是，1的无机部分采用类钙钛矿结构，形成由共面的PbBr₆八面体组成的无限长柱。引人注目的是，有机阳离子表现出高度灵活的分子构型，在T = 338.8 K时引发高于室温的相变；这通过差示扫描量热法（DSC）、比热容（Cₚ）和介电测量得到证实。进一步的结构分析表明，相变源于有机阳离子的分子构型畸变以及无机成分内部PbBr₆八面体的小角度重新取向。此外，温度依赖性电导率和紫外/可见吸收测量表明，1在Tₚ以下也表现出半导体行为。相信这项工作将为利用环状有机胺设计多功能钙钛矿杂化材料铺平一条潜在的道路。
