Organic–inorganic hybrid perovskite [NH 3 (CH 2 ) 5 NH 3 ]ZnCl 4 crystal: growth, structure, phase transition, thermal properties, and structural dynamics

In this study, the physicochemical properties of [NH 3 (CH 2 ) 5 NH 3 ]ZnCl 4 crystals were investigated using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and nuclear magnetic resonance (NMR). The crystals had a monoclinic structure with C2/c space group and lattice constants are a =21.4175 Å, b =7.3574 Å, c =19.1079 Å, β =120.5190°, and Z=8. Phase-transition temperatures in the DSC curve were 256 K, 390 K, and 481 K. Additionally, a small change near 340 K, related to phase transition, was observed in the XRD pattern. NMR studies indicated no change in 1 H chemical shifts, but a change in the chemical shifts for C2, located between C1 and C3 of the cation at 340 K. Increase in molecular motion caused an increase in the spin-lattice relaxation time, T 1ρ , at low spinning rates, under magic-angle spinning (MAS) rate conditions. The inorganic anion was composed of octahedral B Cl 6 , when the metal ion ( B ) was Mn, Cu, and Cd, and tetrahedral B Cl 4 , when B was Zn and Co. The coordination geometries of B Cl 6 and B Cl 4 , connected by N−H∙∙∙Cl hydrogen bonds between Cl and the organic cation, were investigated.