Synthesis and characterization of trinuclear macrocyclic transition metal complexes

Trinuclear macrocyclic metal complexes having oxamide bridges have been synthesized by the interaction of the macrocycle 1,4,7,10-tetraazacyclotetradecane-2,3-dione with Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) chlorides and were characterized by elemental analyses, EPR, electronic, IR, H-1 NMR spectra, conductivity and magnetic susceptibility measurements. The conductivity measurements suggest that the complexes of the divalent metal ions are nonionic while those of the trivalent metal ions appear to be 1:3 electrolytes. On the basis of electronic spectra and magnetic moment values an octahedral geometry is proposed for all of the prepared complexes.