NMR and EPR Spectroscopic Characterization of the Reactive Intermediates of Transition Metal Catalyzed Oxidations Full article
Conference |
13th Summer School on Coordination Chemistry 02-08 Jun 1996 , Polanica Zdroj |
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Journal |
New Journal of Chemistry
ISSN: 1144-0546 , E-ISSN: 1369-9261 |
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Output data | Year: 1997, Volume: 21, Number: 6-7, Pages: 709-725 Pages count : 17 | ||
Tags | ELECTRON-SPIN-RESONANCE; HYDROGEN-PEROXIDE; ORGANIC HYDROPEROXIDES; SELECTIVE OXIDATION; TITANIUM SILICALITE; ALKYLPEROXO COMPLEXES; ALKYL HYDROPEROXIDES; MOLYBDENUM COMPLEXES; IRON(III) PORPHYRINS; COBALT(III) ACETATE | ||
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Abstract:
Multinuclear NMR and EPR spectroscopy can be very fruitful for in situ detection and characterization of the reactive intermediates of transition-metal-catalyzed oxidations. Using H-1 and Co-59 NMR spectroscopy, it was shown that the so-called ''Co(III) acetate''-the reactive intermediate of the cobalt-catalyzed oxidation of alkylbenzenes-is a mixture of trinuclear oxo-centered cobaltic cations, [Co3O(OAc)(5)(OH)(AcOH)(3)](+) and [Co3O(OAc)(6)(AcOH)(3)](+). Using EPR and H-1 NMR spectroscopy, the structure of copper-amine complexes was monitored in the course of the oxidative coupling of 2,6-dimethylphenol to elucidate factors governing the selectivity of the poly(2,6-dimethyl-1,4-phenylene) oxide formation, Superoxo complexes of palladium active toward ethylene epoxidation were detected by EPR. Alkylperoxo and peroxo complexes of Mo-(VI), V-(V), and Ti-(IV), that drive the catalytic cycle of selective epoxidation were characterized directly in reaction solution. The peroxo complex Ti(OEt)(2)(O-2).(EtOH)(2), which selectively epoxidizes cyclohexene and hydroxylate phenol, was observed by H-1 NMR. The low-spin peroxo ferric complexes [Fe(bpy)(2)(OOH)Py](2+) and [Fe(phen)(2)(OOH)Py](2+), which are active towards cyclohexane and cyclohexene oxidation, were detected in ''Gif''-type catalytic systems.
Cite:
Talsi E.P.
NMR and EPR Spectroscopic Characterization of the Reactive Intermediates of Transition Metal Catalyzed Oxidations
New Journal of Chemistry. 1997. V.21. N6-7. P.709-725. WOS РИНЦ
NMR and EPR Spectroscopic Characterization of the Reactive Intermediates of Transition Metal Catalyzed Oxidations
New Journal of Chemistry. 1997. V.21. N6-7. P.709-725. WOS РИНЦ
Dates:
Published print: | Jun 1, 1997 |
Identifiers:
Web of science | WOS:A1997XN48500008 |
Elibrary | 21271747 |
Chemical Abstracts | 1997:535580 |
Chemical Abstracts (print) | 127:205182 |