Synthesis and characterization of macrocyclic complexes of Co (II), Ni (II) and Cu (II)

The ligand 3,8-dimethyl-5,6-benzo-4,7-diazadeca-3,7-diene-2,9-dione dioxime [(DOH)-bzo] has been synthesized by the condensation of o-phneylenediamine with diacetyl monoxime in a 1:2 mole ratio. It has been isolated in the solid state and characterized by CHN data, and IR and NMR spectral studies. Six coordinate Co (II) complex, four coordinate square planar Ni (II) complex and five coordinate square pyramidal Cu (II) complex are synthesized by the reaction of the respective metal chlorides. All these complexes are characterized by infrared, electronic spectroscopy and conductivity measurements. Indirect evidence for the formation of intra-molecular hydrogen bond in these complexes is obtained by replacing the hydrogen bonded proton by BF2 group by treating the complex [Cu (DO) (DOH) bzo) Cl] with BF3OEt2.