High-pressure spectroscopic studies of reactions of the clusters [Rh4(CO)12–x{P(OPh)3}x](x= 1–4) with carbon monoxide or syngas
- 1 January 1991
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in J. Chem. Soc., Dalton Trans.
- No. S,p. 677-683
- https://doi.org/10.1039/dt9910000677
Abstract
The fragmentation and recombination reactions of the clusters [Rh4(CO)12–xLx][L = P(OPh)3, x= 1–4] under applied pressure of CO or CO–H2(1:1) gases have been studied by multinuclear NMR spectroscopy using a high-pressure, high-resolution cell and by high-pressure, IR spectroscopy. Fragmentation to mixtures of dinuclear species [Rh2(CO)8 –xLx](x= 0–2) is observed. The proportions of the variously substituted dimers in the fragmented mixture depends both on the cluster originally present in the solution and on the rhodium concentration. The dimers undergo a fluxional process analogous to that found in [Co2(CO)8]. Recombination on depressurisation can occur either to predominantly the original Rh4 derivative or to mixtures in which several Rh4 species are present in comparable amounts depending on the rhodium to phosphorus ratio. No evidence has been obtained for the formation of hydride species [RhH(CO)4–xLx](x= 0 or 1).Keywords
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