{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T19:18:47Z","timestamp":1792005527870,"version":"4.4.0"},"reference-count":32,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2022,11,19]],"date-time":"2022-11-19T00:00:00Z","timestamp":1668816000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Ministry of Science and Higher Education of the Russian Federation","award":["AAAA-A21-121011490008-3"],"award-info":[{"award-number":["AAAA-A21-121011490008-3"]}]},{"name":"International Cooperation of the Chinese Academy of Sciences","award":["AAAA-A21-121011490008-3"],"award-info":[{"award-number":["AAAA-A21-121011490008-3"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Ethylene polymerization with bis(imino)pyridlyiron precatalysts generally produces linear polyethylene (PE) even with the presence of \u03b1-olefins because \u03b1-olefins are not incorporated into polymeric products. Interestingly, \u03b1-olefins, such as hexene-1 or butene-1, have been found to act as effective chain transfer agents in the ethylene polymerization promoted by nonsymmetrical bis(imino)pyridyliron complexes with modified methylalumoxane (MMAO), resulting in higher catalytic activities with higher amounts of polymers with lower molecular weights, and, more importantly, narrower molecular weight distributions of the resultant polyethylenes (PE). This phenomenon confirms the assistance of \u03b1-olefins in the chain-termination reaction of iron-initiated polymerization and regeneration of the active species for further polymerization. Besides higher activities of the catalytic system, the formation of linear PE with trans-vinylene terminal groups and lower molecular weights are explained. The observation will provide a new pathway for enhancing catalytic activity and improving the quality of polyethylenes obtained by regulation of molecular weights and molecular weight distribution.<\/jats:p>","DOI":"10.3390\/ijms232214384","type":"journal-article","created":{"date-parts":[[2022,11,21]],"date-time":"2022-11-21T02:52:21Z","timestamp":1668999141000},"page":"14384","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Unusual Effect of \u03b1-olefins as Chain Transfer Agents in Ethylene Polymerization over the Catalyst with Nonsymmetrical Bis(imino)pyridine Complex of Fe(II) and Modified Methylalumoxane (MMAO) Cocatalyst"],"prefix":"10.3390","volume":"23","author":[{"given":"Nina V.","family":"Semikolenova","sequence":"first","affiliation":[{"name":"Boreskov Institute of Catalysis, Pr. Lavrentieva 5, 630090 Novosibirsk, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5340-9577","authenticated-orcid":false,"given":"Mikhail A.","family":"Matsko","sequence":"additional","affiliation":[{"name":"Boreskov Institute of Catalysis, Pr. Lavrentieva 5, 630090 Novosibirsk, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vladimir A.","family":"Zakharov","sequence":"additional","affiliation":[{"name":"Boreskov Institute of Catalysis, Pr. Lavrentieva 5, 630090 Novosibirsk, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6614-9284","authenticated-orcid":false,"given":"Wen-Hua","family":"Sun","sequence":"additional","affiliation":[{"name":"Key Laboratory of Engineering Plastics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,11,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"4049","DOI":"10.1021\/ja9802100","article-title":"Highly Active Iron and Cobalt Catalysts for the Polymerization of Ethylene","volume":"120","author":"Small","year":"1998","journal-title":"J. Am. Chem. 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