In Situ Generation of Co III –Salen Complexes for Copolymerization of Propylene Oxide and CO 2

A simple admixture of Co II –salcy complexes with [Cp 2 Fe III ]PF 6 resulted in reproduction of the results with isolated Co III –salcy complexes in the copolymerization of epoxide and carbon dioxide. By using this in situ‐generated active species with bis(triphenylphosphoranilydene)ammonium 2,4‐dinitrophenolate, a para ‐methoxy‐substituted Co–salcy complex was proven to be more active than the parent tert ‐butyl‐substituted system. In contrast, the Co II –salcy complex substituted with the more strongly electron‐donating NMe 2 group did not show any activity for this copolymerization.