Ruthenium production

These results were explained by the discovery that the chloro-ruthenium complexes are not the primary photoproducts under CO in 1.0 M CCl /octane solution. Instead Ru(CO>5 proved to be the initial product even after nearly complete photofragmentation of the starting material, and the chlorocarbonyl ruthenium products to be the result of a secondary, dark reaction between the Ru(C0)5 and CCI4 (3) ... 

However upon standing at ambient conditions the solutions precipitate Ru3(CO)i2 in nearly quantitative yields. Infrared spectra under reaction conditions (400 atm of 1 1 H2/CO, 200°C) also correspond to the spectrum of Ru(CO)5 no acetate or cluster complexes are observed. However, there is evidence for the presence of small amounts of Ru3(CO) 2 under somewhat lower pressures (ca. 200 atm) Many other ruthenium complexes were used as catalyst precursors, and were found to be converted to the same ruthenium products under reaction conditions. For example, H4Ru4(CO)12 (13), [Ru(CO)2(CH3C02)2ln (14) ... 

Pell and Armor found entirely different products in alkaline solution. Above pH 8.3, the sole ruthenium product of the reaction of Ru(NH3)g+ with NO was the dinitrogen complex Ru(NH3)5(N2)2+. Under these conditions the rate law proved to be first-order in [Ru(NH3)g+], [NO] and [OH-]. A likely mechanism is the reversible reaction of Ru(NH3)3+ with OH- to give the intermediate Ru(NH3)5(NH2)2+, followed by electrophilic NO attack at the amide ligand and release of water. However, the kinetic evidence does not exclude other sequences. 

Os6(CO)l8(CNC6H4Me-p)2 (62) have shown the former to have the same Os6 bicapped tetrahedron of the parent compound Os6(CO) g, whereas the latter has a rearranged metal skeleton with one isocyanide bridging three osmium atoms (40). With the ruthenium product Rus(CO),4(CNBu )2 (63), isolated... 

In contrast to complex 3, the methyhdene (PCy3)2(Cl)2Ru=CH2 (4) decomposes according to hrst order kinetics, and its decomposition is not inhibited by the addition of free phosphine. The thermal decomposition products include free PCys and a mixture of unidentihed ruthenium products, but ethylene is not observed in the reaction mixture. Deuteration of the methyhdene ligand leads to incorporahon of deuterium into the PCys ligand, which suggests that the decomposihon of 4 proceeds by intramolecular phosphine achvahon [93]. 

Several groups reported the reachons of catalyst 1 with a variety of NHC ligands [96-99]. The use of derivatives containing relahvely small A-substituents (cyclohexyl, isopropyl) led to the formation of both the mono and bis(NHC) ruthenium products (Fig. 4.36a) [97]. However, the reaction of an excess of 1,3-... 

The dinitrogen complex formation is considered to take place via a series of steps including interaction of the electrophilic NO+ with the nucleophilic NH group of the free amine and elimination of water to form a co-ordinated diazonium ligand with subsequent ligand redox to the observed ruthenium product. 

The PGMs are isolated mainly for platinum and palladium. Iridium, osmium, rhodium, and ruthenium production is... 

The early chemistry of hexanuclear carbonyl clusters, including those of ruthenium and osmium, has been reviewed.The hexaruthenium dianion [RuslCOlis] is prepared inside NaX-zeolite cages in 80-90% yields by treatment of [Ru(NH3)6] /NaX with CO and H2. Oxidation of the supported dianion results in cluster degradation to mononuclear ruthenium products, a process that is reversible on re-exposure to CO/H2. A redetermination of the crystal structure of Os6(CO)i8, as its chloroform solvate, confirms the bicapped tetrahedral metal core seen with the unsolvated cluster. 

Ion implantation has also been used for the creation of novel catalyticaHy active materials. Ruthenium oxide is used as an electrode for chlorine production because of its superior corrosion resistance. Platinum was implanted in mthenium oxide and the performance of the catalyst tested with respect to the oxidation of formic acid and methanol (fuel ceU reactions) (131). The implantation of platinum produced of which a catalyticaHy active electrode, the performance of which is superior to both pure and smooth platinum. It also has good long-term stabiHty. The most interesting finding, however, is the complete inactivity of the electrode for the methanol oxidation. 

At the start of the nineteenth century, platinum was refined in a scientific manner by William Hyde WoUaston, resulting in the successful production of malleable platinum on a commercial scale. During the course of the analytical work, WoUaston discovered paUadium, rhodium, indium, and osmium. Ruthenium was not discovered until 1844, when work was conducted on the composition of platinum ores from the Ural Mountains. 

Miscellaneous. Ruthenium dioxide-based thick-film resistors have been used as secondary thermometers below I K (92). Ruthenium dioxide-coated anodes ate the most widely used anode for chlorine production (93). Ruthenium(IV) oxide and other compounds ate used in the electronics industry as resistor material in apphcations where thick-film technology is used to print electrical circuits (94) (see Electronic materials). Ruthenium electroplate has similar properties to those of rhodium, but is much less expensive. Electrolytes used for mthenium electroplating (95) include [Ru2Clg(OH2)2N] Na2[Ru(N02)4(N0)0H] [13859-66-0] and (NH 2P uds(NO)] [13820-58-1], Several photocatalytic cycles that generate... 

A Belgian patent (178) claims improved ethanol selectivity of over 62%, starting with methanol and synthesis gas and using a cobalt catalyst with a hahde promoter and a tertiary phosphine. At 195°C, and initial carbon monoxide pressure of 7.1 MPa (70 atm) and hydrogen pressure of 7.1 MPa, methanol conversions of 30% were indicated, but the selectivity for acetic acid and methyl acetate, usehil by-products from this reaction, was only 7%. Ruthenium and osmium catalysts (179,180) have also been employed for this reaction. The addition of a bicycHc trialkyl phosphine is claimed to increase methanol conversion from 24% to 89% (181). 

Hydrogenation of 19-nor-A -3-keto steroids also gives 5a- and 5 -product mixtures under the usual conditions but with ruthenium oxide at high pressures only the 5j8-isomer is formed.The presence of a 4-methyl group on a A -3-keto steroid increases the amount of a attack as compared to the parent enone. ... 

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