New bis(macrocyclic) dinickel(II) complexes with bis(Me 2[14]-4,7-dien-6-ylidene), 2a and 2b, were synthesized by oxidation of a dinickel(II) complex with an unsaturated bis(macrocyclic) ligand containing four C N bonds, bis(Me 2[14]-4,7-dien-6-yl) ( 1). Complex 2a was found to undergo intramolecular cyclization between the methyl group of one macrocycle and the carbon atom of the C N group of the other macrocycle to produce a bis(macrocyclic) dinickel(II) complex bridged by a fivemembered ring ( 3). The structures of 2b and 3 were determined by X-ray crystallography. The nonsymmetrical bis(macrocyclic) structure of the dinickel(II) complex 3 was reflected in its cyclic voltammogram and 1H and 13C NMR spectra. The catalytic capabilities of these bis(macrocyclic) nickel(II) complexes in the reductive debromination of 1-bromo-4- tert-butylbenzene were also investigated.