A bimetallic iron(iii) catalyst for CO₂/epoxide coupling

A novel di-iron(iii) catalyst for the copolymerisation of cyclohexene oxide and CO2 to yield poly(cyclohexene carbonate), under mild conditions, is reported. The catalyst selectivity was completely changed on addition of an ammonium co-catalyst to yield only the cis-isomer of the cyclic carbonate, also under mild conditions. Additionally, the catalyst was active for propylene carbonate and styrene carbonate production at 1 atm pressure.