Reactivity of growing radical in the copolymerization of styrenes with oxygen in the presence of cobalt complex

Copolymerizations of a styrene homologue with oxygen were carried out in the presence of a Co(II) (Schiff‐base) complex having a chiral ligand. The metal complex showed a retarding effect on the rate of oxygen absorption in the reaction due to its interaction with growing radicals. Main product was almost an equimolar copolymer of monomer and oxygen, in the case of styrene and α‐methylstyrene. On the other hand, trans epoxide as well as a copolymer having many ether units were formed in the reaction of β‐methylstyrene. The presence of the cobalt complex increased the yield of epoxide and induced asymmetry in the epoxide.