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dc.creatorKeith, Jason M.
dc.creatorTomic, Zoran D.
dc.creatorZarić, Snežana
dc.creatorHall, Michael B.
dc.date.accessioned2018-11-22T00:16:31Z
dc.date.available2018-11-22T00:16:31Z
dc.date.issued2010
dc.identifier.issn1381-1169
dc.identifier.urihttp://cherry.chem.bg.ac.rs/handle/123456789/1087
dc.description.abstractCatalytic oxygen atom transfer (OAT), which frequently employs molybdenum oxo species, is an important reaction for both nature and industry. The mechanistic details of oxygen atom transfer from Tp(R)MoO(2)(XPh) to PMe(3) were investigated for R = 3-iPr and 3-Me and X=O and S by density functional theory (DFT) calculations of the enthalpies, free energy with solvent corrections, and natural bond orbital (NBO) analysis. The mechanism for both systems proceeds via rate-determining attack of PMe(3) to form a stable intermediate with a bound OPMe(3) ligand. From this intermediate the reaction proceeds through a substitution involving loss of OPMe(3) and coordination of a single CH(3)CN solvent molecule. The solvent corrected free energy barriers of the rate-determining OAT step for the O and S systems were found to be energetically more favorable for the S systems by 6.2 and 2.2 kcal/mol (for the R=3-iPr and 3-Me, respectively). This lower energy barrier is the result of better stabilization by the SPh ligand of the Mo(IV) products and the transition states, which are the unexpectedly later and more product-like. Additional examination of the NBO analysis emphasizes the role of the local acidity of the Mo and by extension the character of the ligands. The decreased electronegativity and softer character of the S atom result in an increased covalent character in the Mo-X bond which leads to the stabilization of a later (and lower energy) transition state and the corresponding product of the S system relative to O system. (C) 2010 Elsevier B.V. All rights reserved.en
dc.publisherElsevier Science Bv, Amsterdam
dc.relationinfo:eu-repo/grantAgreement/MESTD/MPN2006-2010/142037/RS//
dc.relationNational Science Foundation [CHE-0518074, CHE-0541587, CHE-0910552]
dc.relationWelch Foundation [A-0648]
dc.rightsrestrictedAccess
dc.sourceJournal of Molecular Catalysis. A: Chemical
dc.subjectOxygen atom transfer (OAT)en
dc.subjectPhosphine oxidationen
dc.subjectMolybdenum catalysisen
dc.subjectDensity functional theoryen
dc.titleOxygen atom transfer catalysis: Ligand effects on the key reaction barrier in molybdenum (VI) dioxo systemsen
dc.typearticle
dc.rights.licenseARR
dcterms.abstractКеитх, Јасон М.; Зарић, Снежана; Халл, Мицхаел Б.; Томиц, Зоран Д.;
dc.citation.volume324
dc.citation.issue1-2
dc.citation.spage15
dc.citation.epage23
dc.identifier.wos000278823100004
dc.identifier.doi10.1016/j.molcata.2010.02.027
dc.citation.other324(1-2): 15-23
dc.citation.rankM22
dc.type.versionpublishedVersionen
dc.identifier.scopus2-s2.0-77954175841
dc.identifier.rcubKon_2087


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