Phase transition, thermal stability, and molecular dynamics of organic-inorganic hybrid perovskite [NH3(CH2)(6)NH3]CuCl4 crystals

Organic-inorganic hybrid perovskites have various potential applications in fuel cells and solar cells. In this regard, the physicochemical properties of an organic-inorganic [NH3(CH2)(6)NH3]CuCl4 crystal was conducted. The crystals had a monoclinic structure with space group P2(1)/n and lattice constants a = 7.2224 angstrom, b = 7.6112 angstrom, c = 23.3315 angstrom, beta = 91.930 degrees, and Z = 4 at 300 K, and the phase transition temperature (T-C) was determined to be 363 K by X-ray diffraction and differential scanning calorimetry experiments. From the nuclear magnetic resonance experimental results, the changes in the H-1 chemical shifts in NH3 and the influence of C1 located close to NH3 in the [NH3(CH2)(6)NH3] cation near T-C are determined to be large, which implies that the structural change of CuCl4 linked to N-HMIDLINE HORIZONTAL ELLIPSISCl is large. The H-1 spin-lattice relaxation time (T-1 rho) in NH3 is shorter than that of CH2, and the C-13 T-1 rho values for C1 close to NH3 are shorter than those of C2 and C3 due to the influence of the paramagnetic Cu2+ ion in square planar geometry CuCl4. The structural mechanism for the phase transition was the change in the N-HMIDLINE HORIZONTAL ELLIPSISCl hydrogen bond and was associated with the structural dynamics of the CuCl4 anion.