Organic–inorganic hybrid [NH(3)(CH(2))(6)NH(3)]ZnBr(4) crystal: structural characterization, phase transitions, thermal properties, and structural dynamics

Organic–inorganic hybrid [NH(3)(CH(2))(6)NH(3)]ZnBr(4) crystals were prepared by slow evaporation; the crystals had a monoclinic structure with space group P2(1)/c and lattice constants a = 7.7833 Å, b = 14.5312 Å, c = 13.2396 Å, β = 90.8650°, 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 (1)H and (13)C chemical shifts were observed near T(C1), indicating changing structural environments around (1)H and (13)C. The spin–lattice relaxation time, T(1ρ), increased rapidly near T(C1) suggesting very large energy transfer, as indicated by a large thermal displacement around the (13)C atoms of the cation. However, the environments of (1)H, (14)N, and C1 located close to NH(3) in the [NH(3)(CH(2))(6)NH(3)] cation did not influence it significantly, indicating a minor change in the N–H⋯Br hydrogen bond with the coordination geometry of the ZnBr(4) anion. We believe that the information on the physiochemical properties and thermal stability of [NH(3)(CH(2))(6)NH(3)]ZnBr(4), as discussed in this study, would be key to exploring its application in stable, environment friendly solar cells.