Thermal property and structural molecular dynamics of organic-inorganic hybrid perovskite 1,4-butanediammonium tetrachlorocuprate.

We investigate the thermal behaviour and physical properties of the crystals of the organic inorganic hybrid perovskite [(NH)(CH)(NH)]CuCl. The compound's thermal stability curve as per thermogravimetric analysis exhibits a stable state up to ∼495 K, while the weight loss observed near 538 K corresponds to partial thermal decomposition. The H nuclear magnetic resonance (NMR) chemical shifts for NH change more significantly with temperature than those for CH, because the organic cation motion is enhanced at both ends of the organic chain. The C NMR chemical shifts for the 'CH-1' units of the chain show an anomalous change, and those for 'CH-2' (units closer to NH) are shifted sharply. Additionally, the N NMR spectra reflect the changes of local symmetry near (=323 K). Moreover, the C values for CH-2 are smaller than those for CH-1, and the C data curve for CH-1 exhibits an anomalous behaviour between 260 and 310 K. These smaller values at lower temperatures indicate that H and C in the organic chains are more flexible at these temperatures. The NH group is attached to both ends of the organic chain, and NH forms a N-H⋯Cl hydrogen bond with the Cl ion of inorganic CuCl. When H and C are located close to the paramagnetic Cu ion, the value is smaller than when these are located far from the paramagnetic ion.