Crystal structures, phase transitions, and nuclear magnetic resonance of organic–inorganic hybrid [NH(2)(CH(3))(2)](2)ZnBr(4) crystals

Organic–inorganic hybrid [NH(2)(CH(3))(2)](2)ZnBr(4) crystals were grown via slow evaporation, and their monoclinic structure was determined using single-crystal X-ray diffraction (XRD). The two phase transition temperatures at 401 K (T(C1)) and 436 K (T(C2)) were defined using differential scanning calorimetry and powder XRD. In the nuclear magnetic resonance spectra, a small change was observed in the (1)H chemical shifts for NH(2), (13)C chemical shifts for CH(3), and (14)N resonance frequency for NH(2) near T(C1). (1)H spin-lattice relaxation times T(1ρ) and (13)C T(1ρ) for NH(2) and CH(3), respectively, rapidly decreased near T(C1), suggesting that energy was easily transferred. NH(2) in the [NH(2)(CH(3))(2)](+) cation was significantly influenced by the surrounding environments of (1)H and (14)N, indicating a change in the N–H⋯Br hydrogen bond with the coordination geometry of the ZnBr(4) anion. These fundamental properties open efficient avenues for the development of organic–inorganic hybrids, thus qualifying them for practical applications.