Synthesis, Structural and Biological Efficiency Studies of New Azo Ligands and Their complxes with Zn(II), Cd(II) and Hg(II) Metal ion

Abstract

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).Beer’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.