Phthalocyanine complexes, chain transfer

Many Co11 porphyrins (87)110 131 and phthalocyanine complexes (102)110 have been examined for their ability to function as catalytic chain transfer agents and much mechanistic work has focused on the use of these catalysts. The more widespread application of these complexes has been limited because they often have only sparing solubility and they are highly colored. 

The porphyrin cobalt complex in radical polymerization of methylmethacrylate catalyzes the chain transfer to the monomer without affecting the polymerization rate. The phthalocyanine cobalt complex catalyzes the chain termination. 

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