| 초록 |
Recently, the CO2/epoxide copolymerization has drawn much attention not only due to the cheapness of CO2 but also due to the environmental issue. The activity of the catalyst at the initial report by Inoue in 1969 was very poor (TON, 6; TOF, 0.12 h-1) but it has been significantly improved in 2000s. The representative examples among the highly active catalytic systems are the binary system of [(Salen)Co or (Salen)Cr complex]/(onium salt or base) and the beta-diketiminatoZn complex. It was proposed that the two components or the two zinc centers are involved in the propagation mechanism. In this presentation, we will show that the catalytic performance is significantly improved by binding the two centers or the two components in a molecule. By binding the two components in a molecule, the turnover frequency (TOF), the turnover number (TON), the selectivity, and the thermal stabbility are dramatically improved for CO2/epoxide copolymerizations. |
