Synthesis, spectral, crystal structure, DFT and Hirshfeld surface analysis of Zn(II) complexes involving dithiocarbamate and imine ligands and usage as precursor to prepare ZnS for photodegradation of dyes

Abstract

Three new zinc(II) complexes, bis(N-(2-phenylethyl)-N-(thiophen-2-ylmethyl)dithiocarbamato-S,S’)zinc(II) (1), bis(N-(2-phenylethyl)-N-(thiophen-2-ylmethyl)dithiocarbamato-S,S’)(pyridine)zinc(II) (2) and (2,2’bipyridine)bis(N-(2-phenylethyl)-N-(thiophen-2-ylmethyl)dithiocarbamato-S,S’)zinc(II) (3) were synthesized. All the complexes were characterized by 1H and 13C NMR and IR spectroscopy, together with elemental analysis. The crystal structures of 2 and 3 were determined by X-ray crystallography, which describe a distorted square pyramidal and distorted octahedral coordination environment around the Zn(II) ion in 2 and 3, respectively. One of the interesting structural features of 2 is the unusual intermolecular C-H…Zn interaction. The optimized structures of 1-3 were obtained using density functional theory at the B3LYP level. Hirshfeld surface analysis and two dimensional finger print plots were examined to study the contributions of the various intermolecular contacts within the supramolecular structure and zinc sulfide nanoparticles were prepared from 1 and 2 characterized using powder X-ray diffraction, scanning electron microscopy, Energy dispersive X-ray spectroscopy and UV-vis diffused reflectance spectroscopy. The PXRD data reveal that the zinc sulfide nanoparticles possess wurtzite structure. The photocatalytic activity of zinc sulfide prepared from 1 was studied by degrading methylene blue and rhodamine-6G in aqueous medium under UV irradiation as a function of time. This study indicates the high catalytic activity of as-prepared ZnS from 1.