Dendritic metallophthalocyanines - Synthesis, electrochemical properties, and catalytic activities

A new class of sterically hindered dendritic phthalocyanines was synthesized to evaluate the effects of the dendritic structure on the electrochemical properties and catalytic activities. This dendritic phthalocyanine possesses a well-defined structure which has a nanosized, three-dimensional shape. The dendritic structure around the cobalt phthalocyanine prevented the molecular aggregation among phthalocyanine moieties in polar solvents and thin films. Electrochemical studies indicated that the electron-transfer process was hindered in the dendritic cobalt phthalocyanine. This is the result of a shielding effect by the dendrimer branch on the cobalt phthalocyanine core. Thiol oxidation catalyzed by the dendritic cobalt phthalocyanine was carried out in the presence of dioxygen. A high stability of the catalytic site was observed for the dendritic cobalt phthalocyanine.