Synthesis, spectral characterization, thermal behavior and biological activities study of ternary metal complexes of alanine and 1,8-diaminonapthalene with Co(III), Ni(II), Cu(II), Zn(II) and Cd(II)

Abstract

Ternary metal complexes derived from different amino acids and aromatic amines are widely employed as biologically active materials, such as antibacterial, antifungal and antioxidant agents. Considering the importance of metal complexes, some ternary complexes have been synthesized by the reaction of cobalt(III) nitrate, nickel(II) chloride, copper(II) chloride, zinc(II) chloride and cadmium(II) chloride with alanine (as a primary ligand) and 1,8-diaminonapthalene (as a supporting ligand) in water- ethanol mixed medium. This metal ligand complexes were characterized by using suitable instrumental techniques. Complexometric, gravimetric and iodometric methods were used to estimate the metal content of the complexes. The IR spectra demonstrated that interactions between the metal ions and ligands occurs through N and O of alaninato ion and N(1,8) of 1,8-diaminonapthalene. The magnetic moment values and characteristic absorption bands that appeared in UV–Vis spectrophotometry corresponds to the square planar geometry for all complexes. The metal complexes have been screened for antibacterial activity against some gram negative (such as- P. aeruginosa. E. coli) and some gram positive (such as- B. subtilis, B. cereus) bacteria and for antifungal activity against Saccharomyces cerevace, Candida albicans and Aspergillus niger. Nickel, zinc and cadmium complexes show antibacterial and antifungal activity whereas cobalt and copper complexes are almost insensitive towards microorganism. Beside this, all the complexes showed significant antioxidant activity.