Synthesis and spectral studies on copper(II) and cobalt(II) complexes of macrocyclic ligand containing thiosemicarbazone moiety

Abstract

New copper(II) and cobalt(II) complexes of macrocyclic Schiff base ligand containing thiosemicarbazone moiety have been prepared with a general composition [M(H₂L²)X₂] [where M = Cu(II) or Co(II); H₂L² = 3,4,9,10-tetraphenyl-1,2,5,6,8,11-hexaazacycldodeca-7, 12-dithione-2,4,8, 10-tetraene; X = Cl^-, NO₃, 1/2 SO₄^2-, and ML² [where salt used is copper acetate and cobalt

thiocyanate]. When the mesocycle 6-ethoxy-1,6-diphenyl-4-thio- 2,3,5-triazine (H₂L¹) in ethanol react with metal salt (chromium chloride) acting as template using high dilution technique, the macrocyclic ligand H₂L² was formed. The complexes have been characterized on the basis of elemental analysis, molar

conductance, magnetic susceptibility, IR, electronic ¹H NMR, Mass and EPR spectral studies. The complexes from H₂L² show different characteristics stoichiometry ratio with a variable grade of deprotonation in the ligand, depending upon the salt used [Cl^-, NO₃^-, 1/2 SO₄^2-, CH₃COO^- or SCN^-] and working conditions.