Investigation of the reaction of [Cp*2M2O 5] (M = Mo, W) with hydrogen peroxide and tert-butylhydroperoxide in MeCN; Implications for olefin epoxidation catalyzed by organomolybdenum and organotungsten compounds Dedicated to Maria-José Calhorda on the occasion of her 65th birthday.

Simple item page
dc.contributor.authorBhaumik C.
dc.contributor.authorManoury E.
dc.contributor.authorDaran J.-C.
dc.contributor.authorSözen-Aktaş P.
dc.contributor.authorDemirhan F.
dc.contributor.authorPoli R.
dc.date.accessioned2024-07-22T08:15:20Z
dc.date.available2024-07-22T08:15:20Z
dc.date.issued2014
dc.description.abstractCompounds [Cp*2M2O5] (M = Mo, W) react with stoichiometric amounts of H2O2 (as a 30% w/w solution in water) and tBuOOH (TBHP, as a 70% w/w solution in decane) in MeCN solution to yield a variety of products as shown by the 1H 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*2Mo 6O17] (1), (C5Me5O)[Cp*M 6O18] (M = Mo, 2a; W, 2b), and (C5Me 5O)2[Mo6O19] (3) were recovered and analyzed by X-ray diffraction. Catalytic cyclooctene epoxidation experiments with (nBu4N)2[M6O19] (M = Mo, W) in a 3:1 MeCN/toluene mixture at 55 °C using either aqueous H 2O2 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, 9572-9584; Eur. J. Inorg. Chem., 2013, 2728-2735). 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. © 2013 Elsevier B.V. All rights reserved.
dc.identifier.DOI-ID10.1016/j.jorganchem.2013.11.029
dc.identifier.issn0022328X
dc.identifier.urihttp://akademikarsiv.cbu.edu.tr:4000/handle/123456789/16717
dc.language.isoEnglish
dc.publisherElsevier B.V.
dc.rightsAll Open Access; Green Open Access
dc.subjectCatalysts
dc.subjectLigands
dc.subjectMolybdenum
dc.subjectMolybdenum metallography
dc.subjectNuclear magnetic resonance
dc.subjectOlefins
dc.subjectOrganometallics
dc.subjectOxidants
dc.subjectOxidation
dc.subjectTungsten
dc.subjectTungsten compounds
dc.subjectCatalyst degradation
dc.subjectCatalytically active species
dc.subjectCyclooctene
dc.subjectCyclopentadienyls
dc.subjectOlefin epoxidation
dc.subjectPentamethylcyclopentadienyl
dc.subjectRate increase
dc.subjectTert-butylhydroperoxide
dc.subjectMolybdenum compounds
dc.titleInvestigation of the reaction of [Cp*2M2O 5] (M = Mo, W) with hydrogen peroxide and tert-butylhydroperoxide in MeCN; Implications for olefin epoxidation catalyzed by organomolybdenum and organotungsten compounds Dedicated to Maria-José Calhorda on the occasion of her 65th birthday.
dc.typeArticle

Files

Collections

Scopus Koleksiyonu