Synthesis and Characterization of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) Complexes With Polydentate 14-Membered Macrocyclic Ligand

This is a chemistry article reporting the synthesis and characterization of a macrocyclic Schiff base ligand and its metal complexes. The ligand (L), a tetraimine macrocycle designated 5,12-dimethyl-7,14-diphenyl-1,3,4,8,10,11-hexaazacyclotetradecane-2,9-dione, is prepared through a [2+2] condensation reaction between semicarbazide and benzoylacetone in a 1:1 molar ratio in aqueous solution at room temperature. Macrocyclic complexes of the general formula [ML]Cl2, where M is cobalt, nickel, copper, zinc, or cadmium, are then synthesized by reacting the ligand with the corresponding metal chlorides in ethanol. The resulting compounds are characterized through analytical and spectroscopic methods.