Carbon dioxide could be a virtually inexhaustible chemical reagent that is cheap and non-toxic. To achieve this, it has to be activated under low-energy conditions. Many catalysts for CO2 activation and fixation are being developed, but most still require high temperatures and pressures. Antonello Decortes and Arjan Kleij, Institute of Chemical Research of Catalonia (ICIQ), Spain, have used a zinc-salphen complex [salphen=N,N’-phenylene-1,2-bis-salicylidene] to generate cyclic carbonates from CO2.
The complex preparation did not require oxygen- and/or moisture-free conditions and, as it used Zn(II), it is not toxic. The cycloaddition of carbon dioxide to various epoxides could be performed under mild conditions (25 °C, pCO2=0.2 MPa) and with a green reaction medium, 2-butanone. This represents one of the few catalytic processes that can exclusively produce cyclic carbonate structures under ambient conditions.
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- Ambient Fixation of Carbon Dioxide using a ZnIIsalphen Catalyst
A. Decortes, A. W. Kleij,