Organic-inorganic hybrid [NH3(CH2)(6)NH3]ZnBr4 crystal: structural characterization, phase transitions, thermal properties, and structural dynamics

Organic-inorganic hybrid [NH3(CH2)(6)NH3]ZnBr4 crystals were prepared by slow evaporation; the crystals had a monoclinic structure with space group P2(1)/c and lattice constants a = 7.7833 angstrom, b = 14.5312 angstrom, c = 13.2396 angstrom, beta = 90.8650 degrees, and Z = 4. They underwent two phase transitions, at 370 K (T-C1) and 430 K (T-C2), as confirmed by powder X-ray diffraction patterns at various temperatures; the crystals were stable up to 600 K. The nuclear magnetic resonance spectra, obtained using the magic-angle spinning method, demonstrated changes in the H-1 and C-13 chemical shifts were observed near T-C1, indicating changing structural environments around H-1 and C-13. The spin-lattice relaxation time, T-1 rho, increased rapidly near T-C1 suggesting very large energy transfer, as indicated by a large thermal displacement around the C-13 atoms of the cation. However, the environments of H-1, N-14, and C1 located close to NH3 in the [NH3(CH2)(6)NH3] cation did not influence it significantly, indicating a minor change in the N-HMIDLINE HORIZONTAL ELLIPSISBr hydrogen bond with the coordination geometry of the ZnBr4 anion. We believe that the information on the physiochemical properties and thermal stability of [NH3(CH2)(6)NH3]ZnBr4, as discussed in this study, would be key to exploring its application in stable, environment friendly solar cells.