Cationic Co–Salphen Complexes Bisligated by DMAP as Catalysts for the Copolymerization of Cyclohexene Oxide with Phthalic Anhydride or Carbon Dioxide

For the copolymerization of cyclohexene oxide (CHO) with phthalic anhydride (PA), cationic complex [Co(III)(dmap)2–Salphen][BF4] (3) showed higher activity than a combination of Co–Salphen–Cl (2) with 1 equiv of DMAP. The catalytic activity was further improved by using a bimetallic complex 5 in which the Co(III)(dmap)2–Salphen moiety was bridged by a 1,2,5,6-substituted naphthalene linker. A similar trend of catalytic activity was detected for the copolymerization of CHO with CO2.