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 P 2 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.