POLYMER-ANCHORED COBALT TETRAARYLPORPHYRIN CATALYSTS FOR THE CONVERSION OF QUADRICYCLANE TO NORBORNADIENE

Methods are described for the preparation of carboxamide- and sulfonamide-linked polystyrene-anchored co-balt(II) tetraarylporphyrins containing 0.28 to 0.44% cobalt, which are highly active catalysts for the conversion of quadricyclane to norbornadiene. These cobalt catalysts gradually lose some of their activity upon repeated recycling. This loss in catalytic activity apparently arises from partial oxidation, since the loss of catalytic activity can be partially restored by treatment with a strong reducing agent such as titanium(III). The apparent activities of these catalysts are increased if the catalyst is finely powdered, thereby suggesting diffusion limitation of the catalytic activity. Applications are discussed of these catalysts in a proposed solar energy storage system based on the reversible valence isomerization of norbornadiene to quadricyclane. © 1979, American Chemical Society. All rights reserved.