Metallophthalocyanine Dimers Incorporating Five Atom Covalent Bridges

摘要

Metal-free, copper, and cobalt(II) binuclear phthalocyanines, in which the two phthalocyanine nucleii are covalently linked through five atom bridges have been prepared and characterized. Some new metal-free, copper, cobalt (II), and zinc 2,9,)6,23-tetraalkoxypthalocyanines, some of which are extremely soluble in organic solvents, are described. The use of cobalt phthalocyanine as a catalyst for the electroreduction of oxygen has been known for some time (1) and extensive efforts have shown that porphyrins and phthalocyanines can act as potential catalysts for energy conversion processes. Binuclear porphyrins have been prepared and used in the 4-electron reduction of molecular oxygen to water. Under operating conditions, however, binuclear porphyrins lose catalytic activity with time and it may be that the porphyrin nucleus itself is not sufficiently stable to be used as a long term photocatalyst. For this reason, we envisioned that binuclear photocatalysts based on the thermally and photochemically stable phthalocyanine nucleus would be worthwhile molecules to synthesize and examine in electrochemical and photocatalytic studies.