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 3 )(CH 2 ) 4 (NH 3 )]CuCl 4 . 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 1 H nuclear magnetic resonance (NMR) chemical shifts for NH 3 change more significantly with temperature than those for CH 2 , because the organic cation motion is enhanced at both ends of the organic chain. The 13 C NMR chemical shifts for the 'CH 2 -1' units of the chain show an anomalous change, and those for 'CH 2 -2' (units closer to NH 3 ) are shifted sharply. Additionally, the 14 N NMR spectra reflect the changes of local symmetry near T C (=323 K). Moreover, the 13 C T 1ρ values for CH 2 -2 are smaller than those for CH 2 -1, and the 13 C T 1ρ data curve for CH 2 -1 exhibits an anomalous behaviour between 260 and 310 K. These smaller T 1ρ values at lower temperatures indicate that 1 H and 13 C in the organic chains are more flexible at these temperatures. The NH 3 group is attached to both ends of the organic chain, and NH 3 forms a N-H⋯Cl hydrogen bond with the Cl ion of inorganic CuCl 4 . When H and C are located close to the paramagnetic Cu 2+ ion, the T 1ρ value is smaller than when these are located far from the paramagnetic ion.