Synthesis, DFT calculations, intermolecular interactions and third order nonlinear optical properties of new organoammonium tetrabromocadmate (II): (C5H6N2Cl)2[CdBr4]·H2O

Abstract A new hybrid compound (C5H6N2Cl)2[CdBr4]·H2O abbreviated CdACP was grown by slow evaporation from an aqueous solution at room temperature. The compound was characterized by single crystal X-ray diffraction, FTIR and Raman spectroscopies. The structural study proved that this compound crystallizes in a triclinic unit-cell with space group P 1 ¯ . To investigate the crystal packing, the structure has been analyzed using the Hirshfeld surface approach. Electronic behavior was analyzed using HOMO–LUMO analysis by density functional theory (DFT) at (DFT/B3LYP/LanL2DZ) level and UV–Vis absorption. The linear optical and electrical parameters (complex dielectric constant and optical and electrical conductivities) of our compound were analyzed using UV–Vis–NIR diffuse reflectance spectroscopy. The higher magnitude of optical conductivity of order 109 s−1 confirms the usefulness of the crystal’s photo response for information processing devices. The direct and indirect band gap values were found to be 4 and 3.8 eV, respectively, which are wide enough to exploit the CdACP crystal for optoelectronics device applications. The dispersion parameters (static refractive index, single oscillator energy ( E 0 ) and dispersion energy ( E d )) were discussed using theoretical Wemple Di-Domenico (WDD) model. The third order nonlinear parameters were investigated using empirical approximations. The sufficient transparency in the visible region, low cut off wave length and the higher values of nonlinear susceptibility χ(3) and nonlinear refractive index n2 make the title crystal suitable for third order NLO applications.