Phase transition, thermal stability, and molecular dynamics of organic–inorganic hybrid perovskite [NH(3)(CH(2))(6)NH(3)]CuCl(4) 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 [NH(3)(CH(2))(6)NH(3)]CuCl(4) crystal was conducted. The crystals had a monoclinic structure with space group P2(1)/n and lattice constants a = 7.2224 Å, b = 7.6112 Å, c = 23.3315 Å, β = 91.930°, 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 (1)H chemical shifts in NH(3) and the influence of C1 located close to NH(3) in the [NH(3)(CH(2))(6)NH(3)] cation near T(C) are determined to be large, which implies that the structural change of CuCl(4) linked to N–H⋯Cl is large. The (1)H spin–lattice relaxation time (T(1ρ)) in NH(3) is shorter than that of CH(2), and the (13)C T(1ρ) values for C1 close to NH(3) are shorter than those of C2 and C3 due to the influence of the paramagnetic Cu(2+) ion in square planar geometry CuCl(4). The structural mechanism for the phase transition was the change in the N–H⋯Cl hydrogen bond and was associated with the structural dynamics of the CuCl(4) anion.