Cooperative Initiation in a Dinuclear Indium Complex for CO<sub>2</sub> Epoxide Copolymerization
Hyuk‐Joon Jung, Kudzanai Nyamayaro, Hassan A. Baalbaki, Chatura Goonesinghe, Parisa Mehrkhodavandi
Abstract
Dinuclear indium complexes have been synthesized and characterized. These include neutral and cationic indium complexes supported by a Schiff base ligand bearing a binaphthol linker. The new compounds were investigated for alternating copolymerization of CO 2 and cyclohexene oxide. In particular, the neutral indium chloride complex (±)-[(O Nap N i N)InCl 2 ] 2 ( 4 ) showed high conversion of cyclohexene oxide and selectivity for poly(cyclohexene carbonate) formation without cocatalysts at 80 °C under various CO 2 pressures (2–30 bar). Importantly, the reactivity of the dinuclear indium chloride complex 4 is drastically different from that of the mononuclear indium chloride complex (±)-(NN i O t Bu )InCl 2 ( 5 ), suggesting a cooperative initiation mechanism involving the two indium centers in 4 .