alpha,alpha '-Bis (imino)-2,3:5,6-bis (pentamethylene)pyridines appended with benzhydryl and cycloalkyl substituents: Probing their effectiveness as tunable N,N,N-supports for cobalt ethylene polymerization catalysts

alpha,alpha '-Bis (imino)-2,3:5,6-bis (pentamethylene)pyridines appended with benzhydryl and cycloalkyl substituents: Probing their effectiveness as tunable N,N,N-supports for cobalt ethylene polymerization catalysts Научная публикация

Журнал

Applied Organometallic Chemistry
ISSN: 0268-2605

Вых. Данные

Год: 2021, Том: 35, Номер: 12, Номер статьи : e6429, Страниц : DOI: 10.1002/aoc.6429

Ключевые слова

cobalt(II) precatalysts; ethylene polymerization; fused bis(imino)pyridine; ortho-cycloalkyl; alpha,alpha '-bis(imino)-2,3:5,6-bis (pentamethylene)pyridines

Авторы

Han Mingyang ^1,2 , Oleynik Ivan I. ³ , Ma Yanping ¹ , Oleynik Irina V. ³ , Solan Gregory A. ^1,4 , Liang Tongling ¹ , Sun Wen-Hua ^1,2,5

Организации

1	(Данные Web of science) Inst Chem Chinese Acad Sci, Natl Lab Mol Sci, Key Lab Engn Plast & Beijing, Beijing 100190, Peoples R China
2	(Данные Web of science) Univ Chinese Acad Sci, CAS Res Educ Ctr Excellence Mol Sci & Int Sch, Beijing, Peoples R China
3	(Данные Web of science) N N Vorozhtsov Novosibirsk Inst Organ Chem, Novosibirsk, Russia
4	(Данные Web of science) Univ Leicester, Dept Chem, Leicester, Leics, England
5	(Данные Web of science) Lanzhou Inst, State Key Lab Oxo Synth & Select Oxidat, Chem Phys Chinese Acad, Lanzhou, Peoples R China

A single-pot method has been utilized to prepare the bis(cycloheptyl)fused N,N,N-cobalt (II) chloride complexes, [2,3:5,6-{C4H8C(NAr)}(2)C5H3N]CoCl2 (Ar 2,6-(C5H9)(2)-4-(CHPh2)C6H2 Co1, 2-(C5H9)-4,6-(CHPh2)(2)C6H2 Co2, 2-(C6H11)-4,6-(CHPh2)(2)C6H2 Co3, 2-(C8H15)-4,6-(CHPh2)(2)C6H2 Co4, 2-(C12H23)-4,6-(CHPh2)(2)C6H2 Co5) in reasonable yields. The molecular structure of Co1 highlights not only the steric shielding of the metal center provided by the N-2,6-dicyclopentyl-4-benzhydrylphenyl groups but also the trans-configuration of the puckered sections of the two fused seven-membered rings. Besides this structural characterization, all complexes have been characterized by elemental analysis and Fourier transform infrared spectroscopy (FT-IR) spectroscopy. In the presence of modified methylaluminoxane (MMAO) or methylaluminoxane (MAO), Co1-Co5 afforded highly linear polyethylenes (T-m's > 126 degrees C) with dispersities that were influenced by the type of aluminoxane activator [M-w/M-n range: 1.53-1.81 (MMAO) vs. 8.96-15.5 (MAO)]. In common to both co-catalysts, the catalytic activity of the pre-catalysts fell in the order: Co1 > Co2 > Co5 > Co4 similar to Co3, reflecting the differences in steric/electronic properties of the ortho-cycloalkyl substituents. In terms of thermostability of the catalyst, Co1/MMAO attained optimal performance at 30 degrees C (2.04 x 10(6) g PE mol(-1)[Co] h(-1)), while Co1/MAO reached it at 60 degrees C albeit with lower productivity (0.70 x 10(6) g PE mol(-1) [Co] h(-1)). In general, the polyethylenes were of reasonably high molecular weight (e.g., between 39.9 and 65.8 kg mol(-1) using MMAO) which can be linked to the steric hindrance imposed on chain transfer by the cycloalkyl and benzhydryl ortho-substituents.

Han M. , Oleynik I.I. , Ma Y. , Oleynik I.V. , Solan G.A. , Liang T. , Sun W-H.
alpha,alpha '-Bis (imino)-2,3:5,6-bis (pentamethylene)pyridines appended with benzhydryl and cycloalkyl substituents: Probing their effectiveness as tunable N,N,N-supports for cobalt ethylene polymerization catalysts
Applied Organometallic Chemistry. 2021. V.35. N12. e6429 . DOI: 10.1002/aoc.6429 WOS Scopus РИНЦ

Web of science	WOS:000692940800001
Scopus	2-s2.0-85114304626
РИНЦ	47071883
OpenAlex	W3198689939