44797-04-8

Upstream product

• 103948-62-5 trans-carbonyl(3-fluorobenzoato)bis(triphenylphosphine)rhodium 
• 112836-45-0 trans-carbonyl(3-fluorobenzoato)bis(tricyclohexylphosphine)rhodium 
• 112837-60-2 (benzoato)carbonylbis(tricyclohexylphosphine)rhodium(I) 
• 14694-95-2 Wilkinson's catalyst 
• 127-19-5 N,N-dimethyl acetamide 
• 201230-82-2 carbon monoxide 

Downstream Products

• 28407-51-4 [Rh6(CO)12(μ3-CO)4] 
• 75506-18-2 HRh(carbonyl)4 

Relevant academic research and scientific papers

ON THE THERMAL GROWTH AND DECOMPOSITION OF RHODIUM CARBONYL CLUSTERS

The growth of anionic rhodium carbonyl clusters under pyrolytic conditions depends upon the counterion.The appearance of complexes of higher nuclearity was least favorable with the cesium salts while it occurred more readily with the ammonium salts following the trend: + (R=alkyl) + (R'=benzyl) + +.A redox reaction between the rhodium carbonyl anion and the ammonium cation is implicated in the thermal growth of clusters.The electron-transfer process between these two moieties may involve the initial fragmentation of the clusters to form -, and the reduction of the ammonium counterions by - at high temperatures, although the direct electron transfer from the polynuclear species to the cation cannot be ruled out yet.It appears that electron transfer precedes or, that it is parallel to, the fragmentation of the clusters while the aggregation reactions of the resulting fragments give the observed products.The formation of metallic rhodium from either mono- or poly-nuclear complexes, and the sequential transformations found for these species are in agreement with the expected thermodynamic preference for high nuclearity species.The existence of the independent effect of the amines and the alkali cations when both of them are present resulted in the inhibition of the formation of metallic rhodium and retarded the growth of the clusters.These results correlate with the enhanced rhodium solubility noted for some catalytic systems that are based on rhodium carbonyl clusters with amines and cesium salts added, and which are used to convert H2/CO mixtures into polyalcohols.

Chemical Behaviour of the Mixed-metal Carbonyl Clustrs (1-) and (2-). Crystal Structures of (1-) and >(1-)

Addition of triphenylphosphine to the cluster (1-) yielded the derivative (1-), which is stable enough to allow a single-crystal X-ray analysis on the (1+) salt.The cluster contains a triangular metallic framework, the vertices of which are occupied by two Fe(CO)4 groups and one Rh(CO)(PPh3) moiety; the unsaturation of the cluster (46 valence electrons) is brought about by this 16-electron square-planar fragment.The cluster (2-) was obtained by treating with (1-) (molar ratio 1 : 2) in refluxing acetone, and was characterized by infrared spectroscopy and elemental analyses.The adduct >(1-) was prepared by stoichiometric addition of in acetone and the crystal structure of the (1+) salt was elucidated by X-ray analysis.The cluster contains a trigonal-bipyramidal arrangement of metal atoms, with one Au(PPh3) and one Fe(CO)3 group occupying the apical positions.The vertices of the FeRh2 equatorial plane are bound to two terminal carbonyl ligands, and the edges are spanned by three bridging carbonyls.The 31P NMR spectral data for (1-) and >(1-) are consistent with the solid-state structures, but do not exclude the presence of fluxional processes in solution.

Formation of anionic carbonylrhodium complexes from Wilkinson's complexes under conditions of hydroformylation of formaldehyde

The compositions and the dynamics of transformations of carbonylrhodium complexes formed from Wilkinson's complexes, RhCl(PPh3)3, dissolved in mesitylene-N,N-dimethylacetamide (DMAA) mixtures in which the DMAA concentration varied from 0 to 100 percent, in an atmosphere of synthesis gas (pCO+H2 = 6 MPa, T = 373 K) were investigated in situ by IR spectroscopy.The anion complexes, - (x = 1, 2; y = 1, 0) and -, which are the centers of formaldehyde hydrofomylation, are produced in noticeable quantities when 100 percent DMAA is used as a solvent.Separate steps of the formation of anionic complexes from RhCl(PPh3)3 have been identified.Under the conditions of hydroformylation of formaldehyde, CH2O participates in the formation of the anionic complexes along with DMAA.

Synthesis and Chemistry of trans-2> (X = Anionic Ligand, L = Tertiary Phosphine)

The novel preparation of a wide variety of trans-2> complexes (X = anionic ligand, L = tertiary phosphine) from , phosphine (L), and acid (HX) is described.A plausible formation pathway is proposed.The electron density on the phosphorous atom in trans-2> decreases and the length of the Rh-P bond increases with an increase in the electronegativity of the anionic ligand, X, in a cis position to the phosphine ligand.The rhodium complexes (X = arylcarboxylate) are reduced to afford rhodate anions such as - and - in hexamethylphosphoroamide solution under CO-H2.The rate of reduction increases with a decrease in the electron-withdrawing effect of the arylcarboxylate ligand.

The Direct Conversion of Synthesis gas into Ethylene Glycol catalysed by RhX(CO)L2 i3)

Higher catalytic activities have been found for RhX(CO)L2 complexes compared to the Rh4(CO)12-L system (molar ratio L:Rh 2:1) for the formation of ethylene glycol from synthesis gas.