Main Article Content
The formation of Zn(II), Cd(II) and Hg(II) complexes was studied with two new hetrocyclic azo ligands 2-[4-(1-sulfonaphthalene)azo]-L-Histidine (L1) and 2-[7-(1-hydroxy3-sulfonaphthalene)azo]-L-Histidine (L2) derived from coupling reaction of diazonium salt of naphthionic acid and 7-amino-1-naphthol-5-sulfonic acid with L-Histidine in an alkaline ethanolic solution. The structural features of all new compounds have been characterized from their elemental analyses, metal content, magnetic moment measurement, molar conductance & FT-IR, UV-Vis. and 1HNMR spectral studies. Furthermore,the composition of complexes have been studied following the mole ratio method after fixing the optimum condition (pH and concentration).Beerâ€™s law was obeyed over a concentration range (6ï‚´10-5 - 8ï‚´10-5M). All data showed that the complexes with (1:2) (M:L) metal to ligand, may be formulated as [M(L)2Cl2] and octahedral geometry, in which the ligands (L1 and L2) act as N,N-bidentate chelating agents, coordinated through the azo nitrogen near naphthyl moiety and heterocyclic nitrogen in L-Histidine. The stability constant (ï¢) and Gibbs free energy (ï„G) of the complexes have also been studied. Biological efficiency of ligands and their complexes were tested aginst Eschericha coli and Staphylococcus aureus.