eng Ansari Education and Research Society Journal of Ultra Scientist of Physical Sciences December 2008 20 3 549 558 jusps-B 1338 article Aderoju A. Osowole (aderoju30@yahoo.com) 1 Benjamin C. Ejelonu 2 Saka A. Balogun 3 Anoganische Chemic II, University Bayreuth, D- 95440 Bayreuth, Germony Department of Chemistry, Adekunle Ajasin University Akungba-Akoko, PMB 001, Akungba-Akoko, Ondo State, NIGERIA Department of Microbiology,Adekunle Ajasin University Akungba-Akoko, PMB 001, Akungba-Akoko, Ondo State, NIGERIA <p style="text-align: justify;">The unsymmetric tetradentate Schiff-base, derived from condensation of 2-hydroxy-4&shy;methoxyacetophenone, ethylenediamine and 2,4-pentanedione and its VO(IV), Co(II), Ni(II) and Cu(II) complexes have been isolated. Their mixed-ligand analogs are obtained by reacting these M(II) Schiff-base complexes with triphenyl phosphine in the ratio 1:1. The ligand was analyzed pure by microanalysis and characterized by ¹Hnmr spectroscopy. The metal complexes were characterized by conductance, magnetic susceptibility, infrared and electronic spectral measurements. The ligand coordinates using azomethine N and phenolic O atums to give 4-coordinate square-planar/tetrahedral geometry to Ni(II), Cu(II) / Co(II), 5-coordinate, square-pyramidal geometry to VO(IV) Schiff base complexes and a 6-coordinate, octahedral geometry to the mixed-ligand complexes with water coordinating to the 6^th position in some of them, as corroborated by magnetic moments, IR and electronic spectral data. The antibacterial activity of ligand and all metal complexes against <em>Escherichia coli,</em> <em>Shigella flexneri, Salmonella typhi,</em> <em>Staphylococcus aureus and Bacillus subtilis</em> are generally good. The mixed-ligand complexes are mostly more effective than the precursor metal(II) Schiff base complexes, which are in turn more effective than the ligand against the bacteria used with exception of <em>Shigella flexneri.</em><br /> &nbsp;</p> https://ultraphysicalsciences.org/paper/1338/ Antibacterial activity unsymmetric Schiff base mixed-ligand triphenyl phosphine.