Synthesis and characterization of bivalent copper and palladium complexes of tetraaza macrocycles bearing polyamide groups

The template condensation of methyl acetoacetate and ethyl acetoacetate wit h 1,2-diaminoethane in the presence of copper and palladium salts resulted in the formation of transition metal complexes of an interesting 14-membere d macrocyclic ligand, N4L. The geometry and the mode of bonding of the resu lting coloured complexes have been inferred from IR, H-1 NMR, mass, EPR and electronic spectral studies. On the basis of magnetic and molar conductanc e data an octahedral geometry around the copper ion is suggested for the [C u(N4L)(NO3)(2)] complex and a square planar geometry is proposed in the cas e of [Pd(N4L)]Cl-2 complex.