Synthesis, Spectroscopic Characterization and in vitro Antibacterial Study of Diorganotin(IV) Complexes of 5-(4-Carboxy-Phenylazo)-2-Hydroxy-Benzoic Acid

Diorganotin(IV) complexes [(R2Sn)2HL] [where, R = methyl-, butyl- and L = 5-(4-carboxy-phenylazo)-2-hydroxy-benzoic acid] were synthesized by reacting sodium salt of the ligand [Na2HL] with dimethyl or dibutyltin(IV) dichlorides in anhydrous methanol using 2:1 metal-ligand ratio. The complexes were characterized by elemental analysis, UV, IR, 1H, 13C, 119Sn NMR spectroscopy, and Mass spectrometry techniques. The coordination geometry of the complexes was determined using 119Sn NMR spectroscopy and was found to be tetrahedral in solution state. The molecular mass and the proposed structure of the complexes have been predicted by the molecular ion peaks in EI-MS spectra of the complexes. The antibacterial activity of the complexes was investigated by screening against different bacteria with respect to standard drug, Gentamycin.