The reaction of mixtures of [Rh4(CO)12] and triphenylphosphite with carbon monoxide or syngas as studied by high-resolution, high-pressure NMR spectroscopy

The fragmentation and redistribution reactions of [Rh4(CO)12-x{P(OPh)3}x] (x = 1-4) with carbon monoxide have been studied using high-resolution, high-pressure NMR spectroscopy. Under the conditions of efficient gas mixing in a high-pressure NMR bubble column, [Rh4(CO)9{P(OPh)3}3] fragments to give...

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Détails bibliographiques
Publié dans:Magnetic resonance in chemistry : MRC. - 1985. - 46 Suppl 1(2008) vom: 15., Seite S100-6
Auteur principal: Overend, Gillian (Auteur)
Autres auteurs: Iggo, Jonathan A, Heaton, Brian T, Whyman, Robin
Format: Article en ligne
Langue:English
Publié: 2008
Accès à la collection:Magnetic resonance in chemistry : MRC
Sujets:Journal Article Research Support, Non-U.S. Gov't Organometallic Compounds Phosphites Carbon Monoxide 7U1EE4V452 Rhodium DMK383DSAC
Description
Résumé:The fragmentation and redistribution reactions of [Rh4(CO)12-x{P(OPh)3}x] (x = 1-4) with carbon monoxide have been studied using high-resolution, high-pressure NMR spectroscopy. Under the conditions of efficient gas mixing in a high-pressure NMR bubble column, [Rh4(CO)9{P(OPh)3}3] fragments to give mainly [Rh2(CO)6{P(OPh)3}2]; [Rh4(CO)11{P(OPh)3}] is also observed,implying redistribution of the phosphite ligand and/or recombination of the dimers to tetrameric clusters. Fragmentation of[Rh4(CO)10{P(OPh)3}2] is found to be pressure-dependent giving predominantly [Rh2(CO)6{P(OPh)3}2] at low CO pressure (1-40 bar), and increasing amounts of [Rh2(CO)7{P(OPh)3}] at higher (40-80 bar) pressure. Using Syngas (CO : H2 (1 : 1)) instead of CO in the above fragmentations, homolytic addition of H2 to the dimer [Rh2(CO)6{P(OPh)3}2] to give [RhH(CO)3{P(OPh3}] and [RhH(CO)2{P(OPh)3}2] is observed. The distribution of tetrameric species obtained is similar to that obtained under the same partial pressure of CO. On depressurisation/out-gassing of the sample, the original mixture of tetrameric clusters is obtained
Description:Date Completed 17.12.2008
Date Revised 21.11.2013
published: Print
Citation Status MEDLINE
ISSN:1097-458X
DOI:10.1002/mrc.2314