Template synthesis and spectroscopic studies of 13-membered oxotetraaza macrocyclic complexes

A new series of 13-membered tetraaza macrocyclic complexes has been prepare d by the template condensation of triethylenetetraamine with ethyl acetoace tate or methyl acetoacetate in a 1:1 molar ratio. All the complexes are sta ble in atmosphere and soluble in DMSO and DMF. The complexes have been char acterized on the basis of analytical, IR, H-1 NMR, EPR, UV-vis, spectra, ma gnetic susceptibility and conductivity data. An octahedral geometry around the metal ion is suggested for manganese, cobalt, and zinc complexes, while a square-planar geometry is proposed for copper and nickel complexes.