Role of Vanadium Alkylperoxo Complexes in Epoxidation of Cyclohexene and Oxidation of Cyclohexane by Organic Hydroperoxides in the Presence of bis (Acetylacetonato)vanadyl Full article
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Journal of Molecular Catalysis (Continued after 1994 as Journal of Molecular Catalysis A: Chemical and Journal of Molecular Catalysis B: Enzymatic)
ISSN: 0304-5102 |
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Output data | Year: 1993, Volume: 81, Number: 2, Pages: 235-254 Pages count : 20 DOI: 10.1016/0304-5102(93)80009-J | ||
Tags | 61V NMR, alkylperoxo complexes, epoxidation mechanisms, vanadium | ||
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Abstract:
Vanadium complexes formed from VO (acac)2 as the starting material for the catalysts have been characterized in situ with 51V and 1H NMR and EPR in the course of three types of catalytic reactions: (1) decomposition of cumene and tert-butyl hydroperoxides in C6D6, (2) epoxidation of cyclohexene in C6D6:cyclohexene=1:1 mixture and (3) oxidation of cyclohexane in C6D6: cyclohexane = 1:1 mixture. In the course of all three reactions VO (acac)2 transforms initially into the alkylperoxo complex VO(acac)2OOR and the alkoxo complex VO(acac)2OR, which further decompose to produce VO (OR)3 and two other vanadium (V) species: an alkylperoxo complex I and an alkoxo complex II. VO (acac)2OOR reacts with cyclohexene to form VO (acac)2OR and cyclohexene oxide. I reacts with cyclohexene to form II and cyclohexene oxide and with ROH to form II and VO(OR)3. II does not react with cyclohexene but reacts with ROOH to form I. No acetylacetonate ligands have been detected in I or II with 1H NMR. I is suggested to be the key species that permits cyclohexene epoxidation with ROOH under steady-state conditions. No complexes of I with cyclohexene are observed with 51V NMR. I does not react directly with cyclohexane, but through the equilibrium VvO(OOR) ⇌ VIVO+RO2· produces free radical RO2· that initiates oxidation of cyclohexane.
Cite:
Talsi E.P.
, Chinakov V.D.
, Babenko V.P.
, Zamaraev K.I.
Role of Vanadium Alkylperoxo Complexes in Epoxidation of Cyclohexene and Oxidation of Cyclohexane by Organic Hydroperoxides in the Presence of bis (Acetylacetonato)vanadyl
Journal of Molecular Catalysis (Continued after 1994 as Journal of Molecular Catalysis A: Chemical and Journal of Molecular Catalysis B: Enzymatic). 1993. V.81. N2. P.235-254. DOI: 10.1016/0304-5102(93)80009-J WOS Scopus РИНЦ
Role of Vanadium Alkylperoxo Complexes in Epoxidation of Cyclohexene and Oxidation of Cyclohexane by Organic Hydroperoxides in the Presence of bis (Acetylacetonato)vanadyl
Journal of Molecular Catalysis (Continued after 1994 as Journal of Molecular Catalysis A: Chemical and Journal of Molecular Catalysis B: Enzymatic). 1993. V.81. N2. P.235-254. DOI: 10.1016/0304-5102(93)80009-J WOS Scopus РИНЦ
Dates:
Submitted: | Dec 14, 1992 |
Accepted: | Jan 12, 1993 |
Published print: | May 10, 1993 |
Published online: | Oct 2, 2001 |
Identifiers:
Web of science | WOS:A1993LD61900009 |
Scopus | 2-s2.0-0027595544 |
Elibrary | 31643811 |
Chemical Abstracts | 1993:625414 |
Chemical Abstracts (print) | 119:225414 |
OpenAlex | W2033620660 |