Macrocyclic metal complexes: Part XIX Synthesis, structure and electron transfer reactions of binuclear nickel(II) macrocyclic complexes

85-87A series of binuclear macrocyclic complexes has been derived by metal ion template condensation of bis-(1,4-dihydrazinophthalazine).with.diketones/dihaloalkanes. Structures of the compounds have been established on the basis of spectral data. The macrocycles undergo reduction in two successive steps. each step involving one electron transfer. The half-wave redox potentials manifest that the first step of the redox process is ligand assisted and depends upon the structural parameters such as ring size, degree of unsaturation and substituents on the macrocyclic ring