Metal ion directed synthesis of 12 and 14-membered tetraaza macrocyclic complexes and their physico-chemical studies

The template condensation reaction of o-phenylenediamine with 2,3-butanedione or 2,4-pentanedione resulted in the formation of new series of 12 and 14-membered tetraaza macrocyclic complexes: [ML1 Cl-2], [ML2 Cl-2] [M=Co(II), Ni(II) and Zn(II)]; [CuL1] Cl-2 and [CuL2] Cl-2. The formation of the macrocyclic framework and the overall geometry of the complexes have been characterized by elemental analyses, FT-IR, (HNMR)-H-1, UV-Visible, magnetic susceptibility and conductivity measurements. The copper( II) complexes exhibit square planar geometry, whereas an octahedral geometry is suggested for all other complexes.