Refined Analysis of the Crystal Structure, Thermodynamic Property, and Structural Geometry of Perovskite (CHNH)ZnBr.

Organic-inorganic hybrid single crystals of (CHNH)ZnBr were grown by the aqueous solution technique, and their structure, phase transition temperature, and thermal stability were discussed. The crystals were determined to have a monoclinic structure using X-ray diffraction on single crystals, and a transition temperature of 458 K was confirmed from the differential scanning calorimetry and X-ray diffraction analyses on powders. Moreover, the compound exhibited excellent thermal stabilities up to 550 K. The H and C nuclear magnetic resonance chemical shifts of CH shifted in the positive direction as the temperature increased, while the H chemical shift of NH exhibited minor variations in N-H···Br hydrogen bonding, which was influenced by minor changes in the bromide ions surrounding Zn in the ZnBr anion. The spin-lattice relaxation time, which indicates the energy transfer near H and C, exhibited similar values, which is because H and C are bonded to each other in the CHNH cation. This compound exhibits high structural and thermal stabilities and is expected to pave the way for future applications.