Kinetic Study of Ethylene Polymerization over 2,6-bis(Imino)pyridine Cobalt Complexes with Bulky Substituents in Ligand Full article
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Journal of Molecular Catalysis A: Chemical
ISSN: 1381-1169 |
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| Output data | Year: 2013, Volume: 366, Pages: 353-358 Pages count : 6 DOI: 10.1016/j.molcata.2012.10.015 | ||
| Tags | Activation energy, Active sites number, Ethylene polymerization catalysts, Polymerization kinetics, Propagation rate constants | ||
| Authors |
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| Affiliations |
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Funding (1)
| 1 | Russian Foundation for Basic Research | 07-03-00311 |
Abstract:
The number of active centers (СP) and propagation rate constants (kP) for ethylene polymerization with single-site homogeneous catalysts composed of cobalt (II) bis(imino)pyridine complexes: 2-tBuLCoCl2 and 2,5-tBu2LCoCl2 (L: 2,6-(C6H3Ndouble bond; length as m-dashCMe)2C5H3N) and methylaluminoxane (MAO) as an activator have been determined by polymerization quenching with radioactive carbon monoxide. The above cobalt complexes provided formation of catalysts, characterized with an increased activity due to the increase in the СP value. The values of propagation rate constant, determined for the studied catalysts, were close (3.6–2.4 × 103 L mol−1 s−1). The values of the constant of the chain transfer reaction with ethylene decreases sharply in the order 2,6-Me2LCoCl2 > 2-tBuLCoCl2 > 2,5-tBu2LCoCl2, being the reason for the increase in the molecular weight of PE, produced with corresponding complexes. For the 2,5-tBu2LCoCl2 + MAO catalyst, the effect of polymerization temperature on the CP and kP values have been studied and the activation energy of propagation reaction was calculated (4.5 kcal mol−1), that was noticeably lower as compared with the effective activation energy (12.5 kcal mol−1), owing to the increase in the CP value with polymerization temperature growth.
Cite:
Barabanov A.A.
, Semikolenova N.V.
, Bukatov G.D.
, Echevskaya L.G.
, Matsko M.A.
, Zakharov V.A.
Kinetic Study of Ethylene Polymerization over 2,6-bis(Imino)pyridine Cobalt Complexes with Bulky Substituents in Ligand
Journal of Molecular Catalysis A: Chemical. 2013. V.366. P.353-358. DOI: 10.1016/j.molcata.2012.10.015 WOS Scopus РИНЦ ANCAN OpenAlex
Kinetic Study of Ethylene Polymerization over 2,6-bis(Imino)pyridine Cobalt Complexes with Bulky Substituents in Ligand
Journal of Molecular Catalysis A: Chemical. 2013. V.366. P.353-358. DOI: 10.1016/j.molcata.2012.10.015 WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
| Submitted: | Feb 14, 2012 |
| Accepted: | Oct 15, 2012 |
| Published online: | Oct 23, 2012 |
| Published print: | Jan 1, 2013 |
Identifiers:
| Web of science: | WOS:000313230200046 |
| Scopus: | 2-s2.0-84870240390 |
| Elibrary: | 20416055 |
| Chemical Abstracts: | 2012:1677018 |
| Chemical Abstracts (print): | 158:56473 |
| OpenAlex: | W1992379985 |