Physicochemical Property Investigations of Perovskite-Type Layer Crystals [NH3(CH2) n NH3]CdCl4 (n = 2, 3, and 4) as a Function of Length n of CH2.

Hybrid perovskites have potential applications in several electrochemical devices such as supercapacitors, batteries, and fuel cells. Here, the thermal stabilities as a function of the length n of the CH2 groups in [NH3(CH2) n NH3]CdCl4 (n = 2, 3, and 4) crystals were considered by TGA and DTA. The structural characteristics and molecular dynamics were studied by MAS and static NMR experiments. A comparison of spin-lattice relaxation times indicated that the organic cation containing 1H and 13C was significantly more flexible than the inorganic anion containing 113Cd. The flexibility of 1H increased with an increase in the length of CH2 in the carbon chain, resulting in a decrease in the activation energy (E a) of 1H. The E a of 13C at n = 3 and 4 was more flexible at high temperatures than at low temperatures. In contrast, the E a of 13C at n = 2 was more flexible at low temperatures. These results provide insight into the thermal stability and molecular dynamics of these crystals as a function of the length n of CH2 groups in the carbon chain and are expected to facilitate applications.