Crystal structure, structural geometry, and molecular motion of organic-inorganic perovskite [N(CH)]MnCl crystals at phases I, II, and III.

Various aspects of the new development of organic-inorganic hybrid [N(CH)]MnCl single crystals have been discussed. The phase transition temperatures were determined to be 268 K (T) and 291 K (T), and the thermodynamic stability was maintained at temperatures up to 669 K. The crystal structures at 250 K (phase III), 275 K (phase II), and 300 K (phase I) are monoclinic, orthorhombic, and orthorhombic, respectively. Notably, while the H and C chemical shifts gradually changed near T and T, the N resonance frequency exhibited a split in the number of signals near T. Furthermore, the shorter spin-lattice relaxation time T of H than that of C suggests facile energy transfer forH. Additionally, analysing the temperature dependencies of T for C revealed that the activation energy E in phase I is approximately five times greater than those in phases III and II. The high E observed in phase I primarily stems from the collective motion of the N(CH) group, which contrasts with the considerable freedom observed for the CH group in phases III and II. These distinctive physical properties suggest potential applications for [N(CH)]MnCl as an organic‒inorganic hybrid material.