Synthesis, structural and DFT studies on copper(II) complexes involving dithiocarbamate ligands having long chain hydrocarbons: precursor for copper sulfide photocatalyst

Bis(N-hexyl-N-(4-methylbenzyl)dithiocarbamato-S,S')copper(II) (1) and bis(N-dodecyl-N-(4-methylbenzyl)dithiocarbamato-S,S')copper(II) (2) have been synthesized and characterized using elemental analysis, FTIR and electronic spectroscopy and single crystal X-ray diffraction technique (SCXRD). X-ray structure analysis of both complexes reveals that the copper(II) has a distorted square planar geometry. The intermolecular interactions in crystal packing are quantified using Hirshfeld surface analysis. Density functional theory (DFT) studies were also performed to validate the experimental SCXRD results. Solvothermal decomposition method has been employed to prepare copper sulfides from complexes 1 and 2. The obtained copper sulfide samples were characterized by powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy. The PXRD patterns of the copper sulfide nanoparticles prepared from 1 and 2 indexed to the orthorhombic phase with estimated crystallite size of 30 nm and 24 nm, respectively. Photocatalytic activity of copper sulfide was evaluated using congo red under UV irradiation. Both copper sulfide nanoparticles are efficient photocatalyst for degradation of congo red dye.