Ruthenium rhodium containing

Polymeric polyolefins, such as polybutadiene, secondary amines, and synthesis gas, are reacted in the presence of a catalyst system comprising a ruthenium-containing compound, a rhodium-containing compound, a steri-cally hindered phosphine, and a solvent [1191]. Preferred polybutadiene feedstocks are those with a predominance of main chain, rather than pendant olefin groups and in particular, those polymers containing both the 1,2-polybutadiene and 1,4-polybutadiene units. These polymers of high amine content are useful as down-hole corrosion inhibitors. 

Other recent reports have also indicated that mixed-metal systems, particularly those containing combinations of ruthenium and rhodium complexes, can provide effective catalysts for the production of ethylene glycol or its carboxylic acid esters (5 9). However, the systems described in this paper are the first in which it has been demonstrated that composite ruthenium-rhodium catalysts, in which rhodium comprises only a minor proportion of the total metallic component, can match, in terms of both activity and selectivity, the previously documented behavior (J ) of mono-metallic rhodium catalysts containing significantly higher concentrations of rhodium. Some details of the chemistry of these bimetallic promoted catalysts are described here. 

Ruthenium and Rhodium Hydrides Containing Chiral Phosphine or Chiral Sulfoxide Ligands, and Catalytic Asymmetric Hydrogenation... 

Ethylene dimerization catalysis has, however, been more thoroughly investigated for the broader range of homogeneous catalysts. For example, active metal complexes containing titanium, nickel, iron, cobalt, rhodium, ruthenium, and palladium, are all known (133). Where possible, comparisons will be made with the relevant homogeneous catalyst systems. 

Purification of Iridium.—In practice the purest iridium obtained by the foregoing process invariably contains small quantities of platinum, rhodium, ruthenium, and iron. In order to remove these, Matthey7 treats the metal as follows. The iridium, in a fine state of division, is fused with ten times its weight of lead, and kept in the molten condition... 

The solution from which the ammonium chlor-platinate has been separated still contains a little platinum with practically all the rhodium, ruthenium, and palladium. All are precipitated by metallic iron and dissolved in aqua regia. Addition of more ammonium chloride effects the precipitation of the remaining platinum, and the filtrate may be worked for the other metals (see p. 154). 

McCormick [5] prepared thiol-stabilized nanoparticles containing gold, platinum, palladium, rhodium, ruthenium, osmium, and iridium, which were used in optics, immunodiagnostics, and electronics. 

On the other hand, divinyl-substituted organosilicon compounds in the presence of ruthenium and rhodium complexes containing or generating M-H and M-Si (M = Ru, Rh) bonds undergo competitive silylative coupling cyclization and polycondensation to give a mixture of oligomers and... 

Me]x-MCM-41 containing nanosized particles of platinum, palladium, rhodium, ruthenium and iridium were directly synthesised from surfactant stabilised spherical metal nanoparticles in the synthesis gel, and characterised with XRD, ICP-AES, TG/DSC, TEM, nitrogen physisorption and carbonmonoxide chemisorption, and Si MAS NMR. During the synthesis some agglomeration of the particles took place, but the metal particles were present inside the pore system of MCM-41. The matericils were active and selective catalysts in the hydrogenation of cyclic olefins such as cyclohexene, cyclooctene, cyclododecene and norbomene. 

Three classes of catalysts have been studied for the asymmetric hydrogenation of imines. One class of catalyst is generated from late transition metal precursors and bisphosphines. These catalysts have typically been generated from rhodium and iridium precursors. A second class of catalyst is based on the chiral titanocene and zirconocene systems presented in the previous section on the asymmetric hydrogenation of unfunctionalized olefins. The third class of catalyst is used for the transfer hydrogenation of imines and consists of ruthenium or rhodium complexes containing diamine, amino tosylamide, or amino alcohol ligands. " ... 

The mechanism for this ostensibly homogeneous process, the Chalk-Harrod mechanism, [264] was based on classical organometallic synthetic and mechanistic research. Its foundation lies in the oxidative addition of the silane Si-H bond to the low oxidation state metal complex catalyst, a reaction which is well established in the organometallic literature. Lewis reported in 1986 that the catalyti-cally active solutions contained small (2.0 nm) platinum particles, and demonstrated that the most active catalyst in the system was in fact the colloidal metal. [60, 265] Subsequent studies established the relative order of catalytic activity for several precious metals to be platinum > rhodium > ruthenium = iridium > osmium. [266] In addition, a dependence of the rate on colloid particle morphology for a rhodium colloid was observed. [267]... 

Interest in metal complexes containing polyfluoroalkyl- and polyfluoro-aryl-acetylenes as ligands has continued to be high, and has included compounds of platinum, palladium, gold, iridium, rhodium, - ruthenium, cobalt, - - nickel, molybdenum, and iron. These are reviewed in detail elsewhere in the Report (see Chapter 5). Such complexes may acquire usefulness for organic synthesis in due course thus significant amounts of hexakis(trifiuoromethyl)benzene are formed when perfluorobut-2-yne is incorporated into certain cobalt and nickel complexes. Similarly, the interesting compound hexakis(pentafluorophenyl)benzene was isolated in 40—70% yield hy trimerization of perfluorodiphenylacetylene over 7C-cyclopentadienylrhodium dicarbonyl in toluene. ... 

Wanat et al. investigated methanol partial oxidation over various rhodium containing catalysts on ceramic monoliths, namely rhodium/alumina, rhodium/ceria, rhodium/ruthenium and rhodium/cobalt catalysts [195]. The rhodium/ceria sample performed best. Full methanol conversion was achieved at reaction temperatures exceeding 550 °C and with O/C ratios of from 0.66 to 1.0. Owing to the high reaction temperature, carbon monoxide selectivity was high, exceeding 70%. No by-products were observed except for methane. 

Higher in activity, but also more costly, are catalysts that contain precious metals such as rhodium, ruthenium, platinum, palladium and rhenium or mixtures thereof [107], while alumina or magnesia [214] and rare earth oxides such as ceria and zirconia or mixtures thereof serve as the carrier material. Rare earth metals have an oxygen storage capability, they interact with the precious metal and generate active sites for hydrocarbon activation [164]. 

It is well established by now that jjn vivo or jji vitro hydrogenation of unsaturated fatty acid residues of lipids can be carried out using complexes of platinum metal ions (mainly rhodium,ruthenium and palladium) containing as ligands various water soluble phosphines Cl], or Alizarin Red (sodium 1,2-di-hydroxyanthraquinone-3-sulfonate, QS), and this method proved to be a fruitful way for investigating the connection between membrane fluidity and the various properties and functions of... 

The aqueous solution of borohydride solved most of these problems by releasing the hydrogen catalytically. A number of different materials would catalyze spontaneous release of hydrogen from a solution of borohydride. The most effective catalysts for hydrogen release were found to be ruthenium and rhodium. Ruthenium metal is known to dissociate water into and OH at its surface [65], and it is surmised that the formation of on the metal surface, even in the basic solutions, is key to the observed catalytic activity. Base metal catalysts containing cobalt and nickel and other metals are also effective catalysts, and this body of literature has been recently reviewed [66] and remains an active area of research. Since a number of surfaces effectively catalyze the hydrolysis, other mechanisms involving interaction of the borohydride (rather than water) have also been discussed [67, 68]. 

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