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

Abstract

We investigate the thermal behaviour and physical properties of the crystals of the organic inorganic hybrid perovskite [(NH3)(CH2)4(NH3)]CuCl4. 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. The1H nuclear magnetic resonance (NMR) chemical shifts for NH3change more significantly with temperature than those for CH2, because the organic cation motion is enhanced at both ends of the organic chain. The13C NMR chemical shifts for the ‘CH2-1’ units of the chain show an anomalous change, and those for ‘CH2-2’ (units closer to NH3) are shifted sharply. Additionally, the14N NMR spectra reflect the changes of local symmetry nearTC(=323 K). Moreover, the13CT1ρvalues for CH2-2 are smaller than those for CH2-1, and the13CT1ρdata curve for CH2-1 exhibits an anomalous behaviour between 260 and 310 K. These smallerT1ρvalues at lower temperatures indicate that1H and13C in the organic chains are more flexible at these temperatures. The NH3group is attached to both ends of the organic chain, and NH3forms a N-H⋯Cl hydrogen bond with the Cl ion of inorganic CuCl4. When H and C are located close to the paramagnetic Cu2+ion, theT1ρvalue is smaller than when these are located far from the paramagnetic ion.