Synthesis, characterization and in vitro antibacterial activity of di- and tri n-butyltin(IV) complexes of 3-amino-4 -chloridobenzohydroxamic acid

Abstract

New di-and tri- n-butyl tin(IV) hydroxamate complexes of composition [n-Bu2Sn(C6H3(3-NH2)(4-Cl)CONHO)2](I) and [n-Bu3Sn(C6H3(3-NH2)(4-Cl)CONHO)] (II) have been synthesized by the reactions of n-Bu2SnCl2 and n-Bu3SnCl with potassium 3-amino-4-chlorido benzohydroxamate(KHL) in predetermined metal:ligand 1:2 and 1:1 molar ratios respectively in MeOH+THF solvent medium and characterized by physiochemical, spectroscopic (IR,1 H and 13 C NMR) studies and mass spectrometry. The bidentate nature of hydroxamate ligand involving bonding through carbonyl and hydroxamic oxygen atoms (O,O coordination) has been inferred from IR spectra. The distorted octahedral and trigonal bipyramidal geometry around tin for (I) and (II) respectively have tentatively been proposed. The electrochemical behavior of complexes studied by cyclic voltammetric technique has shown two electron tin metal centered reductions. The in vitro antibacterial activity of (I) and (II) assayed against pathogenic gram -ve bacteria E.coli , P.aeruginosa; gram +ve bacteria S.aureus, B.cereus by MIC method has revealed these to be promising antibacterial agents relative to parent ligand.