Synthesis, Spectroscopy, Semi-empirical and Biological Activities of Organotin(IV) Complexes with o-Isopropyl Carbonodithioic Acid

New organotin(IV) complexes have been synthesized by treating potassium o-isopropyl carbonodithioate with R2SnCl2/R3SnCl in 1:2/1:1M/L ratio. All complexes have been characterized by IR and NMR (H-1, C-13) spectroscopy. IR results shows that ligand acts as bidentate which is also confirmed by semi-empirical study. NMR data reveals four coordinated geometry in solution. Computed positive heat of formation shows that complex 5 is thermodynamically unstable. UV/visible spectroscopy was used to assess the mode of interaction and binding of the complexes with DNA which shows that complex 5 exhibits higher binding constant as compared to complex 3. In protein kinase inhibition assay, compound 3 was found most active, while other biological activities shows that triorganotin(IV) complexes are biologically more active as compared to diorganotin(IV) complexes.