Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/34496
DC FieldValueLanguage
dc.contributor.authorWei, C.H.en_US
dc.contributor.author洪豐裕zh_TW
dc.contributor.authorWu, C.E.en_US
dc.contributor.authorHuang, Y.L.en_US
dc.contributor.authorKultyshev, R.G.en_US
dc.contributor.authorHong, F.E.en_US
dc.date2007zh_TW
dc.date.accessioned2014-06-06T07:47:50Z-
dc.date.available2014-06-06T07:47:50Z-
dc.identifier.issn0947-6539zh_TW
dc.identifier.urihttp://hdl.handle.net/11455/34496-
dc.description.abstractNew cobalt-containing secondary phosphine oxides [(VLPPh(2)CH(2)pPh(2))CO2(CO)(4){mu,eta-PhC C- P(=O)(H)(R))] (8a: R=tBu; 8b: R= Ph) were prepared by reaction of secondary phosphine oxides PhC=CP(=O)(H)(R) (6a: R=tBu; 6b: R=Ph) with dppm-bridged dicobalt complex [(mu-PPh2CH2PPh2)Co-2(CO)(6)] (2). The molecular structures of 8a and 8b were determined by single-crystal X-ray diffraction. Although palladium-catalyzed Heck reactions employing 8b as ligand gave satisfying results, 8a performed poorly in the same reaction. Judging from these results, a tautomeric equilibrium between 8b and its isomeric form [(mu-PPh(2)CH(2)pPh(2))Co-2(CO)(4){mu,eta-PhC CP(OH)(Ph)}] 8b' indeed takes place, but it is unlikely between 8a and [(mu-PPh2CH2PPh2)Co-2(CO)(4){mu,eta-PhC CP(OH)(tBu)}] (8a'). The DFT studies demonstrated that reasonable activation energies for the tautomeric conversions can be achieved only via a bimolecular pathway. Since a tBu group is much larger than a Ph group, the conversion is presumably only feasible in the case of 8b reversible arrow 8b', but not in the case of 8a reversible arrow 8a'. Another cobalt-containing phosphine, namely, [(mu-PhC CP(OH)(Ph))] 8b' indeed takes place, but it is unlikely between 8a and [(mu-PPh2CH2PPh2)CO2(CO)(4){mu,eta-PhC CP(OH)(tBu)}] (8a'). The DFT studies demonstrated that reasonable activation energies for the tautomeric conversions can be achieved only via a bimolecular pathway. Since a tBu group is much larger than a Ph group, the conversion is presumably only feasible in the case of 8b reversible arrow 8b', but not in the case of 8a reversible arrow 8a'. Another cobalt-containing phosphine, namely, [(mu-PPh2CH2PPh2)Co-2(CO)(4){mu,eta-PhC CP- (NEt2(tBu)}], and its oxidation product [(mu-PPh2CH2PPh2)Co-2(CO)(4)- {mu,eta-PhC CP(=O)(NEt2)(tBu)}] 7a' were prepared from the reaction of PhC CP(NEt2)(tBu) (5a) with 2. The molecular structures of 7a and 7a' were determined by single-crystal Xray diffraction. The phosphorus atom is surrounded by substituents in a tetrahedral environment. A P-N single bond (1.676(3) angstrom) is observed in the molecular structure of 7a. Heck reactions employing 7a/Pd(OAC)(2) as catalyst system exhibited efficiency comparable to that of 8a/Pd(OAC)(2).en_US
dc.language.isoen_USzh_TW
dc.relationChemistry-a European Journalen_US
dc.relation.ispartofseriesChemistry-a European Journal, Volume 13, Issue 5, Page(s) 1583-1593.en_US
dc.relation.urihttp://dx.doi.org/10.1002/chem.200601051en_US
dc.subjectdensity functional calculationsen_US
dc.subjectHeck reactionen_US
dc.subjectP ligandsen_US
dc.subjectpalladiumen_US
dc.subjecttautomerismen_US
dc.subjectcross-coupling reactionsen_US
dc.subjectphosphorus bonded hydrogenen_US
dc.subjectaryl chloridesen_US
dc.subjecttransition-metalen_US
dc.subjectroom-temperatureen_US
dc.subjectmolecular-structureen_US
dc.subjectheck reactionen_US
dc.subjectc-nen_US
dc.subjectdialkyl phosphonatesen_US
dc.subjectbinuclear complexesen_US
dc.titleExperimental and DFT study of the tautomeric behavior of cobalt-containing secondary phosphine oxidesen_US
dc.typeJournal Articlezh_TW
dc.identifier.doi10.1002/chem.200601051zh_TW
item.openairecristypehttp://purl.org/coar/resource_type/c_18cf-
item.fulltextno fulltext-
item.grantfulltextnone-
item.cerifentitytypePublications-
item.languageiso639-1en_US-
item.openairetypeJournal Article-
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