Cobaloxime as a catalytic chain transfer agent

Cobaloxime, synthesized from Co^II acetate and dimethylglyoxime, was used as a chain transfer agent in the free radical polymerization of methyl methacrylate. It proved to be a catalytic chain transfer agent analogous to work recently reported on cobalt porphyrins. Chain transfer constants ranged from 10³–10⁴ and were chain length dependent. Catalytic behavior was demonstrated by calculating turnover numbers which showed that each cobaloxime molecule participated in many hundreds of chain transfer reactions.