New mixed ligand Zn(II) complexes based on the biologically active substituted acetic acid and nitrogen donor ligands : synthesis, crystal structure and biological applications

Abstract

The complexes [Zn(methoxyacetate)21,10-phenanthroline] 1, [Zn2 (phenylacetate)4(quinoline)2] 2, [Zn (phenylacetate)2(2aminopyridin)] 3, [Zn(phenylacetate)2 1,10-phenanthroline] 4, [Zn(phenylacetate)2 2,9- dimethyl-1,10-phenanthroline] 5 were prepared and characterized by IR-spectroscopy, UV-Visible spectroscopy, 1H and 13C NMR spectroscopy, single crystal X-ray diffraction. BNPP hydrolysis of the complexes and their parent nitrogen ligands were scanned, the results showed that BNPP hydrolysis were decreased in the order: complex 2 > 4 > 3 > 1 > 5, the results also showed that these complexes can act as a catalysts for phosphate diester hydrolysis. In addition, anti-bacterial activities were scanned to view the effect of complexation on their activity against Gram-positive (S. epidermidis, S. aureus, E. faecalis, M. luteus and B. Subtilis) and Gram-negative (K. pneumonia, E. coli, P. Mirabilis and P. Aeruginosa) bacteria using agar well-diffusion method. Complex 1 showed high activity against G- and G+ bacteria except against E. faecalis and P. Aeruginosa. Complex 4 showed good activity against G- bacteria except against P. Aeruginosa, G+ bacteria and against E. faecalis. Complex 5 showed zero activity against G- bacteria but low activity against M. luteus, B. Subtilis bacteria and high activity against S. epidermidis and S. aureus. Complexes 2 and 3 did not show any activity against G- or G+ bacteria.