New bis(macrocyclic) dinickel(II) complexes obtained by oxidation of bis(5,7-dimethyl-1,4,8,11-tetraazacyclotetradeca-4,7-dien-6-yl)dinickel(II) perchlorate

New bis(macrocyclic) dinickel(II) complexes with bis(Me2[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 CN bonds, bis(Me2[14]-4,7-dien-6-yl). Complex 2a was found to undergo intramolecular cyclization between the methyl group of one macrocycle and the carbon atom of the CN group of the other macrocycle to produce a bis(macrocyclic) dinickel(II) complex bridged by a five-membered ring (3).