Synthesis, structural characterization and antimicrobial activities of triorganotin(IV)azo-carboxylates derived from ortho/para-amino benzoic acids and β-naphthol

Abstract

Triorganotin (IV) complexes 1–3 were synthesized by the reaction of azo-carboxylic acid viz. 2/4-(2-hydroxynaphthylazo)benzoic acids with appropriate triorganotin(IV) chlorides [R = Me (compounds 1 and 2) and Bu (compound 3)] in presence of triethyl amine base. The complexes were characterized by elemental analysis, IR and multinuclear (1H and 13C- and 119Sn)-NMR spectroscopy. The structures and mode of coordination around tin ions in the complexes were determined by single crystal X-ray crystallography. The complexes exhibit trigonal bipyramidal geometry around tin atoms where the base of the equatorial plane is being occupied by the three alkyl groups [Me or Bu] while the axial positions are occupied by carboxylate oxygen atoms in 2 and in case of 1 and 3, by carboxylate and phenoxide oxygen atoms, respectively. It has been found that, the crystal structure of 1 or 3 is a cyclic dimeric, whereas 2 exhibits a polymeric structure. The 119Sn NMR studies show that all complexes have four-coordinate structures indicating dissociation of these complexes in solution state. The complexes were also screened for their antimicrobial activity and the compound 3 was found to exhibit effective antimicrobial activity.