Effect of functionalization of N-bound organic moiety in zinc(II) dithiocarbamate complexes on structure, biological properties and morphology of zinc sulfide nanoparticles

Abstract

Bis(N-furfuryl-N-substituted benzyldithiocarbamato-S,S′)zinc(II) (1–4) [substituted benzyl=4F–C6H4–CH2– (1), 4Cl–C6H4–CH2– (2), 4OH–C6H4–CH2– (3), 4OCH3–C6H4–CH2– (4)] complexes were prepared and characterized by elemental analysis, IR and NMR (1H and 13C) spectroscopy. Structures of complex 2 and 4 were determined by single crystal X-ray crystallography. X-ray crystal structure of 2 revealed that the complex is dimeric and the geometry of this coordination polyhedron [ZnS5] is intermediate between tetragonal pyramid and trigonal bipyramid. The structure of 4 features, in contrast to 2, mononuclear species and the coordination geometry for the zinc atom is a highly distorted tetrahedron. The energy gap between the HOMO and LUMO in dimer 2 is lower than those of monomers (2 and 4). This indicates that the monomers are more stable than dimer. In vitro cytotoxic activity of the complexes 1–4 was evaluated on KB cell line. Complex 1 showed better cytotoxic activity than other complexes. These complexes were also screened for in vitro antibacterial and antifungal activities. Complexes 2 and 4 have been used as single source precursors for the preparation of ZnS nanoparticles. As-prepared ZnS nanoparticles were characterized using PXRD, TEM, UV–Vis and photoluminescence spectroscopy. TEM images show that spherical and rod nanoparticles were obtained from complexes 2 and 4, respectively. The photocatalytic activities of the as-prepared ZnS nanoparticles were evaluated by degradation of rhodamine B in aqueous solution under UV irradiation.