De novo synthesis of trivalent metal complexes with ligand derived from N 1 -[2-(2-Amino-ethylimino)-1-methyl-propylidene]-ethane-1,2-diamine and 4-chloro benzoic acid: spectroscopic validation and in vitro biological studies

Nitrogen containing potent donor ligand (L) was produced as a result of the reaction between a Schiff's base N (1) -[2-(2-Amino-ethylimino)-1-methyl-propylidene]-ethane-1,2-diamine and 4-chloro benzoic acid and successfully employed for the preparation of mononuclear metal complexes with general formula [M(L)X-2]center dot X (where, M = Fe(III), Cr(III), Co(III) or Mn(III) and X = Cl- or CH3COO-). Synthesized compounds were structurally elucidated by elemental analyses, conductivity and magnetic measurements as well as spectral techniques viz. infra red, ultraviolet-visible, H-1 nuclear magnetic resonance, C-13 nuclear magnetic resonance, electro-spray ionization mass spectrometry and thermo-gravimetric analysis. Analytical as well as spectral studies favor N-4 type tetra-dentate coordination behavior of (L) and hexa-coordinated octahedral environment around a metal ion with 1:1 electrolytic nature. In vitro antimicrobial behavior of a lone pair donating moiety (L) and coordination compounds were screened with targeted bacterial strains Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhi and fungal strains Aspirgillus niger, Aspirgillus flavus, Candida albicans, and Candida parapsilosis. The results indicate amplified activity of metal complexes compared to free ligand against the studied bacteria and fungi.