Chair of Chemical Materials Science, Department of Chemistry, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.
DPI, P.O. Box 902, 5600 AX Eindhoven, the Netherlands.
J Am Chem Soc. 2022 Aug 31;144(34):15879-15884. doi: 10.1021/jacs.2c07200. Epub 2022 Aug 17.
While controlled free-radical polymerizations are established for a vast range of vinyl monomers, they have not been reported for carbon monoxide, although it is a unique monomer that forms in-chain keto groups which can promote, for example, desirable photo-degradability in polyethylenes. We report organometallic-mediated radical copolymerization of carbon monoxide with ethylene initiated by an organocobalt compound to keto-modified polyethylenes with up to 15 mol % ketone repeat units. Terpolymerization with 2-methylene-1,3-dioxepane affords polyethylenes with in-chain ester and keto groups. Compared to ethylene homopolymerization, the controlled character of the copolymerization is strongly enhanced by the Lewis base function of carbon monoxide, which suppresses multiple unfavorable termination pathways.
虽然可控自由基聚合已广泛应用于各种乙烯基单体，但尚未有关于一氧化碳的报道，尽管一氧化碳是一种独特的单体，它可以形成链内酮基，从而促进例如聚乙烯的光降解。我们报告了一氧化碳与乙烯的有机金属介导自由基共聚，该共聚由有机钴化合物引发，可得到酮改性的聚乙烯，其酮重复单元高达 15mol%。与 2-亚甲基-1,3-二恶烷的三元共聚可得到具有链内酯基和酮基的聚乙烯。与乙烯均聚相比，一氧化碳的路易斯碱功能强烈增强了共聚的可控性，抑制了多种不利的终止途径。
