Metal-ion directed synthesis of binuclear octaazamacrocyclic complexes of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) and their physico-chemical studies

A novel series of 16-membered binuclear complexes of octaazatetraimine ligand, [M2LX4] [M = Mn-II,Co-II stop, Ni-II stop, Cu-II stop and Zn-II stop; X = Cl or NO3] have been synthesized by metal template condensation reactions of o-phenylenediamine with N,N'-diacetylhydrazine in 1:1:1 molar ratio in methanol. The proposed stoichiometry and the bonding of the macrocyclic moiety to metal ions along with the overall stereochemistry have been derived from the results of elemental analyses, magnetic susceptibility, conductivity data and the spectral data revealed from FT-IR,(1) H-NMR,ESI mass, UV-visible studies. An octahedral geometry has been envisaged for Mn-II stop, Co-II stop, and Ni-II stop complexes while a slight distortion in octahedral geometry has been noticed for Cu-II stop complexes. The low conductivity data of all the complexes suggest their non-ionic nature.