title: In Situ Generation of Co(III) -Salen Complexes for Copolymerization of Propylene Oxide and CO2.
abstract: A simple admixture of Co(II) -salcy complexes with [Cp2 Fe(III) ]PF6 resulted in reproduction of the results with isolated Co(III) -salcy complexes in the copolymerization of epoxide and carbon dioxide. By using this in situ-generated active species with bis(triphenylphosphoranilydene)ammonium 2,4-dinitrophenolate, a para-methoxy-substituted Co-salcy complex was proven to be more active than the parent tert-butyl-substituted system. In contrast, the Co(II) -salcy complex substituted with the more strongly electron-donating NMe2 group did not show any activity for this copolymerization.
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hatazawa
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Nakabayashi
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Ohkoshi
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan. nozaki@chembio.t.u-tokyo.ac.jp.
authors.forename: Kyoko
authors.identifier: http://orcid.org/0000-0002-0321-5299
authors.initials: K
authors.lastname: Nozaki
keywords: carbon dioxide; cobalt; epoxides; ligand effects; polymerization