Synthesis, Crystal Structure, Vibrational Study, Optical Properties and Hirshfeld Surface Analysis of a New Centrosymmetric Hybrid Material, Bis(3-Aminoquinolium) Tetrachloridocobaltate (II)

Abstract: The title organic-inorganic hybrid compound (C9H9N2)2[CoCl4] crystallizes at room temperature in the monoclinic C2/c space group. Its atomic arrangement can be described as an alternation of organic-inorganic layers along the c-axis. Crystal cohesion of the compound is achieved through N-H…Cl hydrogen bonds between the anions and cations and through cycle stacking interactions between organic cations. The vibrational properties were studied by Fourier Transform Infrared (FTIR) spectroscopy. The three-dimensional Hirshfeld surface (3D-HS) analysis and the two-dimensional fingerprint plots (2D-FP) were generated to quantify the weak intermolecular interactions present in the crystal. The optical properties were investigated by optical absorption and photoluminescence measurements. The band gap energy indicates that the compound behaves as an insulator material. Photoluminescence results suggest that the title compound can have a potential application as a non-linear optical material.