Integrating Ring-Size Adjustable Cycloalkyl and Benzhydryl Groups as the Steric Protection in Bis(arylimino)trihydroquinoline-Cobalt Catalysts for Ethylene Polymerization

Integrating Ring-Size Adjustable Cycloalkyl and Benzhydryl Groups as the Steric Protection in Bis(arylimino)trihydroquinoline-Cobalt Catalysts for Ethylene Polymerization Full article

Journal

European Journal of Inorganic Chemistry
ISSN: 1434-1948 , E-ISSN: 1099-0682

Output data

Year: 2021, Volume: 2021, Number: 38, Pages: 3956-3968 Pages count : 13 DOI: 10.1002/ejic.202100573

Tags

Benzhydryl substitution; Cobalt catalysts; Cycloalkyl substitution; Ethylene polymerization; Molecular weight control

Authors

Zhang Randi ^1,2,3 , Oleynik Irina ⁴ , Li Jianqing ⁵ , Solan Gregory A. ^1,2,6 , Ma Yanping ^1,2 , Jin Liqun ⁵ , Oleynik Ivan I. ⁴ , Hu Xinquan ⁵ , Sun Wen-Hua ^1,2,3

Affiliations

1	Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190 China
2	(Данные Web of science) Chinese Acad Sci, Inst Chem, Beijing Natl Lab Mol Sci, Beijing 100190, Peoples R China
3	CAS Research/Education Center for Excellence in Molecular Sciences, University of Chinese Academy of Sciences, Beijing, 100049 China
4	Vorozhtsov Novosibirsk Institute of Organic Chemistry, Pr. Lavrentjeva 9, Novosibirsk, 630090 Russia
5	(Данные Web of science) Zhejiang Univ Technol, Coll Chem Engn, Hangzhou 310014, Peoples R China
6	(Данные Web of science) Univ Leicester, Dept Chem, Univ Rd, Leicester LE1 7RH, Leics, England

Combined condensation and complexation of 2-acetyl-5,6,7-trihydroquinolin-8-one, cobalt(II) chloride and the corresponding aniline has been employed as an effective one-pot route to the 2-(1-(arylimino)ethyl)-8-arylimino-5,6,7-trihydroquinoline-cobalt(II) chlorides (aryl=2-Me-4-(CHPh2)-6-(C5H9)C6H2 Co1, 2-Me-4-(C5H9)-6-(CHPh2)C6H2 Co2, 2-(C5H9)-4-Me-6-(CHPh2)C6H2 Co3, 2-(C5H9)-4,6-(CHPh2)(2)C6H2 Co4, 2-(C6H11)-4,6-(CHPh2)(2)C6H2 Co5, 2-(C8H15)-4,6-(CHPh2)(2)C6H2 Co6, 2-F-4,6-(CHPh2)(2)C6H2 Co7, 2-Cl-4,6-(CHPh2)(2)C6H2 Co8, 2-Me-4,6-(CHPh2)(2)C6H2 Co9). All complexes have been well characterized including by single crystal X-ray diffraction for Co3. On activation with either MAO or MMAO, Co1 was the most active for ethylene polymerization with the MAO-activated precatalyst reaching a peak level at 60 degrees C (up to 13.66x10(6) g (PE) mol(-1)(Co) h(-1)). By varying the electronic and steric properties of the ortho- and/or the para-substituents of the N-aryl groups, excellent control over molecular weight could be achieved with values falling in the range 0.97-101.63 kg mol(-1) obtainable. Notably, with a benzhydryl group positioned on the ortho-position of the N-aryl group, a significant enhancement of the molecular weight was observed, while the least bulky ortho-cyclopentyl substituent led to increased catalytic activity. As a final point, distinctive microstructural characteristics of the polyethylenes were observed with Co1/MAO producing near quantitative levels of vinyl end groups.

Zhang R. , Oleynik I. , Li J. , Solan G.A. , Ma Y. , Jin L. , Oleynik I.I. , Hu X. , Sun W-H.
Integrating Ring-Size Adjustable Cycloalkyl and Benzhydryl Groups as the Steric Protection in Bis(arylimino)trihydroquinoline-Cobalt Catalysts for Ethylene Polymerization
European Journal of Inorganic Chemistry. 2021. V.2021. N38. P.3956-3968. DOI: 10.1002/ejic.202100573 WOS Scopus РИНЦ

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