Investigation of the reaction of [Cp*2M2O5](M = Mo, W) with hydrogen peroxide and tert-butylhydroperoxide in MeCN; implications for olefin epoxidation catalyzed by organomolybdenum and organotungsten compounds

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dc.contributor.authorBhaumik, C
dc.contributor.authorManoury, E
dc.contributor.authorDaran, JC
dc.contributor.authorSözen-Aktas, P
dc.contributor.authorDemirhan, F
dc.contributor.authorPoli, R
dc.date.accessioned2024-07-18T12:05:31Z
dc.date.available2024-07-18T12:05:31Z
dc.description.abstractCompounds [Cp*2M2O5] (M Mo, W) react with stoichiometric amounts of H2O2 (as a 30% w/w solution in water) and (BuOOH)-Bu-t (TBHP, as a 70% w/w solution in decane) in MeCN solution to yield a variety of products as shown by the H-1 NMR monitoring of the Cp* resonance. The reaction rate increases in the order W < Mo and TBHP < H2O2. While the total Cp* intensity remains constant when using stoichiometric amounts of oxidant, use of excess oxidant results in the ultimate total Cp* loss. From the decomposed solutions, crystals of [Cp*2Mo6O17] (1), (C5Me5O)[Cp*M6O18] (M Mo, 2a; W, 2b), and (C5Me(5)O)(2)[Mo6O19] (3) were recovered and analyzed by X-ray diffraction. Catalytic cyclooctene epoxidation experiments with ((Bu4N)-Bu-n)(2)[M6O19] (M Mo, W) in a 3: 1 MeCN/toluene mixture at 55 degrees C using either aqueous H2O2 or TBHP/decane as oxidant revealed that these are not the active forms of the catalyst which is generated under the same conditions from [Cp*2M2O5], as reported in previous contributions from our group (Chem. Eur. J., 2010, 16, 9572e9584; Eur. J. Inorg. Chem., 2013, 2728e2735). Further catalytic studies using aged [Cp*2Mo2O5]/TBHP and [Cp*2W2O5]/H2O2 solutions show a small loss of activity (< 50% in one week) attesting the robustness of the non-organometallic catalytically active species that is generated from the decomposition of [Cp*2M2O5]. These results cast doubts on the role of cyclopentadienyl as a supporting ligand for stable olefin epoxidation catalysts. (C) 2013 Elsevier B. V. All rights reserved.
dc.identifier.issn0022-328X
dc.identifier.other1872-8561
dc.identifier.urihttp://akademikarsiv.cbu.edu.tr:4000/handle/123456789/9808
dc.language.isoEnglish
dc.publisherELSEVIER SCIENCE SA
dc.subjectCYCLOPENTADIENYL-MOLYBDENUM COMPLEXES
dc.subjectMAIN-GROUP ELEMENTS
dc.subjectTUNGSTEN COMPLEXES
dc.subjectETA(5)-CYCLOPENTADIENYL MOLYBDENUM
dc.subjectTRICARBONYL COMPLEX
dc.subjectTRANSITION-METALS
dc.subjectMULTIPLE BONDS
dc.subjectOXIDATION
dc.subjectOXIDES
dc.subjectPRECURSORS
dc.titleInvestigation of the reaction of [Cp*2M2O5](M = Mo, W) with hydrogen peroxide and tert-butylhydroperoxide in MeCN; implications for olefin epoxidation catalyzed by organomolybdenum and organotungsten compounds
dc.typeArticle

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