Selective Ethylene Trimerization by Titanium Complexes Bearing Phenoxy-Imine Ligands: NMR and EPR Spectroscopic Studies of the Reaction Intermediates Full article
| Journal |
Organometallics
ISSN: 0276-7333 , E-ISSN: 1520-6041 |
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| Output data | Year: 2014, Volume: 33, Number: 6, Pages: 1431-1439 Pages count : 9 DOI: 10.1021/om500017r | ||||||||
| Tags | Catalysts; Chemical reactions; Chlorine compounds; Ethylene; Ligands; Spectroscopic analysis | ||||||||
| Authors |
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| Affiliations |
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Funding (4)
| 1 | Russian Foundation for Basic Research | 14-03-31155 |
| 2 | Russian Foundation for Basic Research | 14-03-91153 |
| 3 | Sichuan Normal University, College of Chemistry and Materials Science | |
| 4 | National Natural Science Foundation of China | 21211120163 |
Abstract:
The catalyst systems (FI)TiCl3/MAO (FI = phenoxyimine ligand with an additional aryl–O–CH3 donor) display exceptionally high activity in selective ethylene trimerization. By means of NMR and EPR spectroscopy, the nature of the Ti species formed in the catalyst systems (FI)TiCl3/MAO, (FI)TiCl3/MMAO, and (FI)TiCl3/AlR3/[Ph3C]+[B(C6F5)4]− (R = Me, Et, iBu) has been studied. It was shown that outer-sphere ion pairs of the type [(FI)TiIVMe2]+[A]− ([A]− = [MeMAO]−, [MeMMAO]−, [B(C6F5)4]−) are formed at the initial stage of the reaction of (FI)TiCl3 with MAO, MMAO, and AlMe3/[Ph3C]+[B(C6F5)4]−. These ion pairs further partially convert into TiIII and TiII species. In the systems (FI)TiCl3/MAO and (FI)TiCl3/AlMe3/[Ph3C]+[B(C6F5)4]−, complexes with the proposed structures (FI)TiIIIMe2, (FI)TiIICl, and [(FI)TiII(S)]+[A]− ([A]− = [MeMAO]−, [B(C6F5)4)]−, S = solvent, vacancy) were observed (concentrations of TiIII species was lower than those of the TiII congeners). In contrast, in the system (FI)TiCl3/MMAO, the concentrations of TiIII species (ion pairs of the type [(FI)TiIII(μ-H)(μ-Cl)AliBu2]+[MeMMAO]−) were higher than those of the TiII counterparts (ion pairs [(FI)TiII(S)]+[MeMMAO]−). The system (FI)TiCl3/MMAO displays lower activity and selectivity in 1-hexene formation, in comparison to (FI)TiCl3/MAO, due to undesirable PE generation. Probably, TiII and TiIV ion pairs are those participating in ethylene trimerization.
Cite:
Soshnikov I.E.
, Semikolenova N.V.
, Ma J.
, Zhao K-Q.
, Zakharov V.A.
, Bryliakov K.P.
, Redshaw C.
, Talsi E.P.
Selective Ethylene Trimerization by Titanium Complexes Bearing Phenoxy-Imine Ligands: NMR and EPR Spectroscopic Studies of the Reaction Intermediates
Organometallics. 2014.
V.33. N6. P.1431-1439. DOI: 10.1021/om500017r
WOS
Scopus
РИНЦ
OpenAlex
ANCAN
Selective Ethylene Trimerization by Titanium Complexes Bearing Phenoxy-Imine Ligands: NMR and EPR Spectroscopic Studies of the Reaction Intermediates
Organometallics. 2014.
V.33. N6. P.1431-1439. DOI: 10.1021/om500017r
WOS
Scopus
РИНЦ
OpenAlex
ANCAN
Files:
Full text from publisher
Dates:
| Submitted: | Jan 8, 2014 |
| Published online: | Mar 12, 2014 |
| Published print: | Mar 24, 2014 |
Identifiers:
| ≡ Web of science: | WOS:000333478400015 |
| ≡ Scopus: | 2-s2.0-84896986178 |
| ≡ Elibrary: | 21869255 |
| ≡ OpenAlex: | W2330559276 |
| ≡ Chemical Abstracts: | 2014:397655 |
| ≡ Chemical Abstracts (print): | 160:458012 |