Synthesis, structural characterisation and antibacterial activity of bis(1-phenyl-1,3-butanedionato)non-oxovanadium(IV) hydroxamates

Abstract

Complexes with a composition of VCl_2-n(bzac)₂(HL^1,2)_n (I – IV) (where bzac = 1-phenyl-1,3-butanedionate anion (C₆H₅COCHCOCH₃⁻); HL¹=C₆H₅OCH₂C(O)NHO⁻, HL² = C₆H₅CH=CHC(O)NHO⁻, n = 1 and 2) have been synthesised from the reactions of (VCl₂(bzac)₂) with equi- and bi-molar amounts of potassium phenoxyacetohydroxamate and cinnamohydroxamate (KHL^1,2) in THF + MeOH solvent medium. The complexes have been characterised by elemental analyses, molar conductivity, magnetic measurements, IR, electronic and mass spectral studies. The physicochemical and spectral studies suggest a distorted octahedral geometry around vanadium in the complexes. The antibacterial activities of the newly synthesised complexes, vanadium precursor and ligands have been screened in vitro against six bacterial species. The complexes have shown higher antibacterial effect than the free ligands.

Keywords::

• Potassium phenoxyaceto-hydroxamate
• potassiumcinnamohydroxamate
• non-oxovanadium (IV) complexes
• spectral studies
• antibacterial activity

Acknowledgements

The authors would like to thank IIT Roorkee for magnetic susceptibility measurements and Department of Biotechnology, Himachal Pradesh University, Shimla for providing laboratory facilities.

Declaration of interest

Meena Kumari would like to thank the University Grant Commission, New Delhi for providing financial support. The authors would like to thank the Department of Science & Technology (DST), Government of India, New Delhi for providing financial assistance for use of the FT-IR and UV-Vis. spectrophotometer facility to the department. The authors would also like to thank Sophisticated Analytical Instrument Facility of CDRI, Lucknow and Punjab University, Chandigarh for recording mass spectra and elemental analysis.