Spectroscopic, thermal, quantum chemical calculations and in vitro biological studies of titanium/zirconium(IV) complexes of mono-and disubstituted aryldithiocarbonates

Abstract Aryldithiocarbonates of titanium(IV) and zirconium(IV) corresponding to [(ROCS 2 ) 2 MCl 2 ] (R =  o -, m - or p -CH 3 C 6 H 4 and 4-Cl-3-CH 3 C 6 H 3 ; M = Ti or Zr) have been isolated by the reaction of sodium salt of dithiocarbonates with titanium or zirconium tetrachloride in 1:2 M ratio in CHCl 3 . Donor stabilized addition complexes of titanium/zirconium with aryldithiocarbonates were also successfully isolated in chloroform. These have been characterized by elemental analyses, IR, mass, TGA/DTA, SEM and heteronuclear NMR ( 1 H, 13 C and 31 P) spectroscopic studies. The antimicrobial test of these complexes has also been conducted against the bacteria Klebsiella pneumonia and Enterococcus faciolus and fungus Fusarium oxysporium , which indicate potential antimicrobial activity. In addition, the antioxidant activities of the complexes were also investigated through their scavenging effect on DPPH radicals. Density Functional Theory (DFT) calculations have been carried out to investigate geometry parameters of the complexes using B3LYP method and LANL2DZ basis set. HOMO (Highest Occupied Molecular Orbital), LUMO (Lowest Unoccupied Molecular Orbital) energies are analyzed. Based on analytical and theoretical results, a hexacoordinate geometry is concluded around the Ti or Zr atom.