| 초록 |
CO2/epoxide copolymerization catalyzed by metal complexes has drawn much attention recently. The activity of the catalyst at the initial report by Inoue in 1969 was very poor (TON, 6; TOF, 0.12) but it has been significantly improved in the 2000’s. In this study we prepared various salen-cobalt complexes varying either the ortho-substituent or the number of attached quaternary ammonium salts. The prepared complexes were screened for the CO2/epoxide copolymerization, and showed activity of one order higher than the previously reported catalytic system (TON ＞ 20,000; TOF ＞ 20, 000: Mn, 300,000). After the polymerization the catalyst can be easily separated by filtration trough a short pad of silica gel to yield a resin containing negligible amount of metal residue(1-2 ppm). The separated catalyst can be reused without significant loss in catalytic performance. |
