Potential bioactive mononuclear diorganotin(IV) phenoxyacetohydroxamate complexes: synthesis, characterization and antimicrobial evaluation

The new diorganotin(IV) complexes of composition [Me2Sn(C6H5OCH2CONHO)2](I) and [n-Bu2Sn(C6H5OCH2CONHO)2](II) have been synthesized by the reactions of Me2SnCl2 and n-Bu2SnCl2 with potassium phenoxyacetohydroxamate (PhOAHK=C6H5OCH2CONHOK) in 1:2 molar ratio in methanol and benzene solvent medium and characterized by elemental analyses and spectroscopic techniques (infrared, 1H nuclear magnetic resonance and mass spectrometry). The [O,O coordination] through carbonyl and hydroxamic oxygen atoms and distorted octahedral geometry around the mononuclear tin has been inferred. The electrochemical behavior of complexes studied by the cyclic voltammetric technique has shown quasi-irreversible two-step reduction from tin (IV) to tin (II). Thermal behavior of complexes studied by the thermogravimetric technique in N2 atmosphere has yielded SnO as the decomposition product. The in vitro antimicrobial activity assays against various pathogenic Gram-negative bacteria, namely, Salmonella typhi, Escherichia coli; Gram-positive Bacillus cereus and Staphylococcus aureus and fungi Aspergillus niger and Alternaria alternata by the minimum inhibitory concentration method have shown their potential as promising antimicrobial agents compared to the respective standard chloramphenicol and nystatin drugs.