Olefin Epoxidation by Peroxo Complexes of Cr, Mo, and W. A Comparative Density Functional Study Full article
| Journal |
Journal of Organic Chemistry
ISSN: 0022-3263 , E-ISSN: 1520-6904 |
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| Output data | Year: 2000, Volume: 65, Number: 10, Pages: 2996-3004 Pages count : 9 DOI: 10.1021/jo9916784 | ||||||
| Tags | alkene; chromium derivative; ethylene; metal complex; molybdenum complex; oxygen; tungsten derivative | ||||||
| Authors |
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| Affiliations |
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Funding (4)
| 1 | Federal Ministry of Science, Research and Economics | 03D0050B |
| 2 | International Association for the Promotion of Co-operation with Scientists from the New Independent States of the Former Soviet Union | IR-97-1071 |
| 3 | Verband der Chemischen Industrie | |
| 4 | German Research Foundation |
Abstract:
The epoxidation of olefins by peroxo complexes of Cr(VI), Mo(VI) and W(VI) was investigated using the B3LYP hybrid density functional method. For the mono- and bisperoxo model complexes with the structures (NH3)(L)M(O)2-n(η2-O2)1+n (n = 0, 1; L = none, NH3; M = Cr, Mo, W) and ethylene as model olefin, two reaction mechanism were considered, direct oxygen transfer and a two-step insertion into the metal−peroxo bond. The calculations reveal that direct attack of the nucleophilic olefin on an electrophilic peroxo oxygen center via a transition state of spiro structure is preferred as significantly higher activation barriers were calculated for the insertion mechanism than for the direct mechanism. W complexes are the most active in the series investigated with the calculated activation barriers of direct oxygen transfer to ethylene decreasing in the order Cr > Mo > W. Barriers of bisperoxo species are lower than those of the corresponding monoperoxo species. Coordination of a second NH3 base ligand to the mono-coordinated species, (NH3)M(O)2(η2-O2) and (NH3)MO(η2-O2)2, results in a significant increase of the activation barrier which deactivates the complex. Finally, based on a molecular orbital analysis, we discuss factors that govern the activity of the metal peroxo group M(η2-O2), in particular the role of metal center.
Cite:
Di Valentin C.
, Gisdakis P.
, Yudanov I.V.
, Rösch N.
Olefin Epoxidation by Peroxo Complexes of Cr, Mo, and W. A Comparative Density Functional Study
Journal of Organic Chemistry. 2000. V.65. N10. P.2996-3004. DOI: 10.1021/jo9916784 WOS Scopus РИНЦ ANCAN OpenAlex
Olefin Epoxidation by Peroxo Complexes of Cr, Mo, and W. A Comparative Density Functional Study
Journal of Organic Chemistry. 2000. V.65. N10. P.2996-3004. DOI: 10.1021/jo9916784 WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
| Submitted: | Oct 26, 1999 |
| Published print: | May 1, 2000 |
Identifiers:
| Web of science: | WOS:000087262500021 |
| Scopus: | 2-s2.0-0034685749 |
| Elibrary: | 13358672 |
| Chemical Abstracts: | 2000:252687 |
| Chemical Abstracts (print): | 133:349915 |
| OpenAlex: | W2085633428 |