Ruthenium-containing catalysts

Other processes include the production of phenol from cyclohexene in which phenol is produced from cyclohexene (benzene is partially hydrogenated to cyclohexene in the presence of water and a ruthenium-containing catalyst). The cyclohexene is then reacted with water to form cyclohexanol or oxygen to form cyclohexanone, and the cyclohexanol or cyclohexanone is dehydrogenated to phenol. 

The value of vNN for N2 adsorbed on ruthenium-containing catalysts is very sensitive to the electronic state of the active surface. The IR spectrum of N2 adsorbed on ruthenium catalysts supported on dealuminated zeolite Y contains bands due to Ru (N2)(CO) (VN2 2218 cmvCO 2123 cm" ) and Ru (N2)2 (vN2 2207,2173... 

In molecules containing both an acetylenic and a nitro function, either or both may be reduced. Preferential reduction of the acetylenic function is best achieved with palladium (42,44). Ruthenium, on the other hand, favors selective reduction of an aromatic nitro function high yields of (3-aminophenyljacetylene were obtained from the corresponding nitro compound. Catalyst life is prolonged by protection of the acetylenic function (70). Cobalt polysulffde and ruthenium sulffde catalysts have been used similarly, but more vigorous conditions are required (100°C, 25-70 atm) (71). 

When the ruthenium EXAFS for the ruthenium-copper catalyst is compared with the EXAFS for a ruthenium reference catalyst containing no copper, it is found that they are not very different. This indicates that the environment about a ruthenium atom in the bimetallic catalyst is on the average not very different from that in the reference catalyst. This result is consistent with the view that a ruthenium-copper cluster consists of a central core of ruthenium atoms with the copper atoms present at the surface. 

Since ruthenium and rhodium are neighboring elements in the periodic table, a closer comparison of the properties of ruthenium-copper and rhodium-copper clusters is of interest (17). When we compare EXAFS results on rhodium-copper and ruthenium-copper catalysts in which the Cu/Rh and Cu/Ru atomic ratios are both equal to one, we find some differences which can be related to the differences in miscibility of copper with ruthenium and rhodium. The extent of concentration of copper at the surface appears to be lower for the rhodium-copper clusters than for the ruthenium-copper clusters, as evidenced by the fact that rhodium exhibits a greater tendency than ruthenium to be coordinated to copper atoms in such clusters. The rhodium-copper clusters presumably contain some of the copper atoms in the interior of the clusters. 

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. 

Ruthenium complexes containing this ligand are able to reduce a variety of double bonds with e.e. above 95%. In order to achieve high enantioselectivity, the reactant must show a strong preference for a specific orientation when complexed with the catalyst. This ordinarily requires the presence of a functional group that can coordinate with the metal. The ruthenium-BINAP catalyst has been used successfully with unsaturated amides,23 allylic and homoallylic alcohols,24 and unsaturated carboxylic acids.25... 

KAAP [Kellogg advanced ammonia process] The first high-pressure process developed for synthesizing ammonia from its elements which does not use an iron-containing catalyst. The reformer gas for this process is provided by the KRES process. The catalyst was developed by BP it contains ruthenium supported on carbon. Developed by MW Kellogg Company in 1990 and first installed by the Ocelot Ammonia Company (now Pacific Ammonia) at Kitimat, British Columbia, from 1991 to 1992. Another plant was installed at Ampro Fertilizers in Donaldsonville, LA, in 1996. 

Carbonyls. Related to the chalcogenide and metal cluster studies are the carbonyl studies for ORR.189 I92-198-201 The majority of the carbonyl work has been reported by several Mexican research groups. This body of work appears to have developed from studies on ruthenium-containing chalcogenide catalysts in the mid-1990 s. The precursors used for these catalysts involved Ru-carbonyls.202... 

Most of the catalysts employed in PEM and direct methanol fuel cells, DMFCs, are based on Pt, as discussed above. However, when used as cathode catalysts in DMFCs, Pt containing catalysts can become poisoned by methanol that crosses over from the anode. Thus, considerable effort has been invested in the search for both methanol resistant membranes and cathode catalysts that are tolerant to methanol. Two classes of catalysts have been shown to exhibit oxygen reduction catalysis and methanol resistance, ruthenium chalcogen based catalysts " " and metal macrocycle complexes, such as porphyrins or phthalocyanines. ... 

Gmbbs has described a chiral ruthenium-based catalyst and has illustrated its application to enantioselective desymmetrization. The catalyst is a derivative of Grubbs second-generation dihydroimidazolinylidene-containing catalyst with the chirality derived from diphenylethanediamine in the carbene backbone. Substrate 90 undergoes ringclosing metathesis in 90% ee on treatment with this catalyst and Nal ... 

Carbon monoxide partial pressures exceed ca. 70 bar (5). Spectroscopic studies of typical Ru3(C0)i2 Co2(C0)8-l2/ Bu4PBr catalyst solutions have served to aid considerably in unraveling the differing roles of the ruthenium, cobalt and iodide-containing catalyst components in these syntheses. A typical solution spectrum in the metal-carbonyl region (5) shows the presence of significant concentration s of both [Ru(CO)3I3] (2108 and 2036... 

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. 

Research Focus Air-stable and high-activity ruthenium-based catalysts containing Schiff base ligands useful in olefin metathesis agents or in atom or group transfer reactions. 

Title Alkylidene Complexes of Ruthenium Containing A-Heterocyclic Carbene Ligands Use as Highly Active, Selective Catalysts for Olefin Metathesis... 

Originality Although ruthenium polymerization catalysts containing Schiff bases are... 

Metathesis reactions involving the metal-alkylidene catalyst component as the active species nonbulky monomers are more active than their bulky counterpart. To address this limitation, 5-norbomene monomer containing an unhindered or bulky 2-substituents were metathesized with favorable reaction kinetics using ruthenium-containing complexes illustrated below. 

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