Alternating copolymerization of carbon dioxide and propylene oxide under bifunctional cobalt salen complexes: Role of Lewis base substituent covalent bonded on salen ligand |
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| Authors: | Binyuan Liu Yanhao Gao Xin Zhao Weidong Yan Xianhong Wang |
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| Affiliation: | 1. Institute of Polymer Science and Engineering, Hebei University of Technology, Tianjin 300130, People's Republic of China;2. State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China |
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| Abstract: | Alternating copolymerization of propylene oxide (PO) and carbon dioxide (CO2) was realized under mild conditions with a moderate turnover frequency (TOF), employing sole bifunctional cobalt salen complexes containing Lewis acid metal center and covalent bonded Lewis base on the ligand. Variation of the covalent bonded Lewis base substituents on the salen ligands could tailor the catalytic activity with TOF changing from 19.3 to 34.9 h?1, polymeric/cyclic carbonate selectivity from 95.3 to 72.8%, and the head‐to‐tail structure in the polymer from 72.2 to 86.0%. The IR analysis confirmed that the Lewis base moiety on one molecule could coordinate with cobalt center of adjacent molecule, playing similar role to the Salen metal complex/Lewis base binary catalytic system. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 359–365, 2010 |
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| Keywords: | carbon dioxide catalysts cobalt salen complex copolymerization polycarbonate propylene oxide |
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