Synthesis, characterization and antimicrobial activity of some nitrilotriacetic acid-V(III), -Sn(II), -Sm(II) and -Sm(III) complexes

Abstract

Four new complexes [V(NTA)(H₂O)₂]×H₂O (1), H[Sn(NTA)] (2), H[Sm(NTA)]×H₂O (3), and [Sm(NTA)(H₂O)₂]×H₂O (4) were obtained during the reactions of metal salts (VCl_3, SnCl₂×2H₂O, SnCl₄, Sm(NO₃)₂×6H₂O and SmCl₃×6H₂O) with nitrilotriacetic acid, H₃NTA. The infrared and ¹H-NMR spectra of the solid complexes have been obtained and assigned. Thermogravimetric analyses were also carried out. The data obtained agree with the proposed structures and show that the complexes decomposed to the corresponding metal oxide. The ligand and their metal complexes were screened for their antimicrobial activities by the agar-well diffusion technique using DMSO as a solvent against the following bacterial species: Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa and antifungal activity against Aspergillus niger, Aspergillus flavus, Saccharomyces cerevisiae and Candida albicans. The obtained results were compared with some types of known antibiotics. The minimum inhibitory concentration (MIC) values were calculated at 30 °C for 24-48 h. The activity data show that the complexes are more potent antimicrobials than the parent ligand.

KEY WORDS: Nitrilotriacetic acid, Metal complexes, IR, ¹H-NMR Spectroscopy, Thermal analysis, Antimicrobial activity

Bull. Chem. Soc. Ethiop. 2011, 25(1), 61-71.