Complexes of binucleating ligands. III. Novel complexes of a macrocyclic binucleating ligand

By reaction of 5-methylisophthalaldehyde with 1,3-diaminopropane in the presence of various metal salts the following complexes have been isolated: MCu2Cl2,6H2O, MCu2(ClO4)2,2H2O, MCu2(HSO4)2,H2O, MNi2Cl2,2H2O, MCo2Cl2,2CH3OH, MFezCl2,2CH3OH, MMn2Cl2,2H2O, MZn2Cl2,2H2O, (MH2)Ni(ClO4)2,2H2O where MH2 represents the macrocyclic tetrakis-Schiff base obtained by condensation of two molecules each of the diamine and dialdehyde components and M represents the derived dianion which behaves as a novel macrocyclic binucleating ligand. On the basis of magnetic and spectral evidence the complexes are assigned binuclear structures in which the cations are in an approximately square-pyramidal environment. These structural features have been confirmed in the case of MCu2Cl2,6H2O by an independently conducted X-ray crystallographic analysis. It is suggested that (MH2)Ni(ClO4)2,H2O is closely related to the others in that the nickel environment is square-pyramidal and that essentially the same organic ligand framework is present, with two protons rather than a metal ion occupying the second cavity of M.