Synthesis, characterization, semi-empirical study, and biological activities of organotin(IV) and transition metal complexes with o-methyl carbonodithioate

Three transition metal and six organotin(IV) complexes have been synthesized by treating potassium o-methyl carbonodithioate with ZnCl2/CdCl2/HgCl2 and R2SnCl2/R3SnCl under stirring. The complexes were characterized by IR, H-1, and C-13 NMR spectroscopies. IR results show that the ligand is bidentate in 1-3 while monodentate in 4-9, which is also confirmed by semi-empirical study. NMR data reveal four-coordinate geometry in solution. HOMO-LUMO study shows that 7 and 9 are thermodynamically unstable. The enzyme inhibition study shows that 1 is a potent inhibitor of ALP, EC 3.1.3.1, resulting in very slow rate of formation and breakdown of enzyme-substrate complex. UV/visible spectroscopy was used to assess the mode of interaction and binding of the complexes with DNA which shows that 9 exhibits higher binding constant when compared to 6. In protein kinase inhibition assay, 1 was active, while antifungal activity shows that organotin(IV) complexes are more active than transition metal complexes.