Solid state synthesis, characterization and antimicrobial studies of co(ii) and ni(ii) metal complexes with Schiff base derived from L-valine and vanillin

Two polynuclear metal complexes with general formula [Ni4L4(H2O)12].2H2O and [Co3L3(H2O)9].5H2O have been synthesized via solid state synthesis with Schiff base derived from vanillin and L-valine. The compounds were characterized by elemental analysis, ESI-Mass spectrometry, infrared spectroscopy, thermogravimetric analysis (TGA) and conductivity measurements. Data from experimental results showed that the ligand binds to two metal centers in a tridentate (N O O) manner through the imine nitrogen, phenolic and carboxylic oxygen respectively. Antimicrobial activities of the ligand and its corresponding metal complexes were investigated and found active  against some selected bacterial and fungal species. Keywords: solid–state reaction, polynuclear metal complexes, mass spectrometry, thermal decomposition, antimicrobial activity.