Synthesis, structural and spectroscopic studies, DFT calculations, thermal characterization and Hirshfeld surface analysis of copper(II) organic-inorganic hybrid material (C12H22N2)[CuCl4

Abstract

A new organic-inorganic hybrid compound, (C12H22N2)[CuCl4], has been synthesized by slow evaporation at room temperature and characterized using elemental analysis, powder X-ray diffraction, FT-IR, UV–Vis and mass spectroscopy. Single-crystal X-ray diffraction analysis indicates that the asymmetric unit in this compound consists of one tetrahedral [CuCl4]2- ion and one diprotonated organic cation (C12H22N2)2+, all of which lie in general positions. The crystal structure of the title salt is made up of mixed layers, formed by organic cations and inorganic anions, stacking along the b-axis. Crystal cohesion is achieved through N-H…Cl hydrogen bonds between organic cations and inorganic anions, and Cl…Cl interactions, building up a two-dimensional architecture. Thermal behavior (DTA/TGA) of this copper complex was also explored showing the different steps of weight loss. Hirshfeld surface analysis has been performed to investigate the intermolecular interactions and crystal packing of the title compound. Optical properties were recorded at room temperature using UV-visible spectroscopy in the spectral range 200-700 nm. The optical absorbance was measured to determine the optical band gap using Kubelka-Munk function. The electronic transition of the title complex was recorded in ethanol solvent and the electronic distribution of HOMO − LUMO was rationalized theoretically through density functional theory (DFT).