Ru process

The ligands 369 react with [RuCl2(dmso)4] to yield [RuCl2(dmso)2(369-A, 0)], characterized W spectroscopic and electrochemical methods. Complexes in the families [Ru"(bpy)(370)2] and [Ru" (aca( (370)2] have been reported. The complexes [Ru(bpy)(370)2] undergo a reversible Ru"/Ru" oxidation followed by an irreversible Ru /Ru process the bpy-centered one-electron reduction is also observed. Chemical oxidation of the complexes [Ru(bpy)(370)2] gives [Ru(bpy)(370)2] (isolated as the iodides), the electronic and ESR spectroscopic properties of which have been described. The crystal structure of [Ru(acac)(371)2] has been established, and the electrochemical and chemical redox reactions of [Ru(acac)(370)2] and [Ru(acac)(371)2] generate Ru" and Ru species that have been characterized by spectroscopic and electrochemical techniques. ... 

Recent reports from Humphrey and colleagues have included several demonstrations of redox-switching of quadratic and cubic NLO responses in Ru"o--acetylides [114, 115, 118, 123], Such compounds generally display reversible Ru "" processes at potentials similar to those of the ammine species studied by Coe et al. [36]. The first switching of nonlinear absorption (a cubic effect) was achieved with two... 

Ru(0EP)X]20 (X = Cl , Br , OH) shows three, two electron redox couples in CHjClj assigned to Ru" Ru /Ru Ru and Ru" Ru /Rti Ru processes and oxidation of the porphyrin rings More recently, oxidation of [Ru(porph)CO] (porph = 429) with MCPBA or iodosyl benzene has yielded the trans-dioxo ruthenium(VI) species [Ru(porph)02] which reacts with P(OMe)j to give two equivalents of MejPO and [Ru(porph)(P(OMe)3)2]. Interestingly, oxidation of the tolyl complex (419) yielded the Ru fx-oxo dimer, suggesting that steric hindrance of (429) is important for the generation of the mononuclear Ru oxo derivative. " ... 

In the iridium bimetallic, [(tpy)Ru(tpp)IrCl3][PF6]2, the first two reductions (at -0.29 and -0.83 V) are based on the tpp ligand. The first oxidation (+1.56 V) is a Ru" " process followed closely by Ir " oxidation [63]. The proximity of the ruthenium and iridium orbitals results in the lowest energy absorption band (about 660 nm) having Ir(dJt) tpp(Jt ) MLCT character. The emission is from a triplet Ru(dTt) - tpp(jt ) CT excited state. This results from energy transfer from the Ir to the Ru center. 

The UV-visible absorption spectrum of Ru(2,2 -bipyridine)3 maximum at about 450 nm, from which the energy in volts for process XI-39 may be estimated. The standard reduction potential for the R" /R couple is about 1.26 V at 25°C. Estimate from this information (and standard reduction potentials) the potential in volts for processes XI-40 and XI-41. Repeat the calculation for alkaline solutions. 

Cyclohexane, produced from the partial hydrogenation of benzene [71-43-2] also can be used as the feedstock for A manufacture. Such a process involves selective hydrogenation of benzene to cyclohexene, separation of the cyclohexene from unreacted benzene and cyclohexane (produced from over-hydrogenation of the benzene), and hydration of the cyclohexane to A. Asahi has obtained numerous patents on such a process and is in the process of commercialization (85,86). Indicated reaction conditions for the partial hydrogenation are 100—200°C and 1—10 kPa (0.1—1.5 psi) with a Ru or zinc-promoted Ru catalyst (87—90). The hydration reaction uses zeotites as catalyst in a two-phase system. Cyclohexene diffuses into an aqueous phase containing the zeotites and there is hydrated to A. The A then is extracted back into the organic phase. Reaction temperature is 90—150°C and reactor residence time is 30 min (91—94). 

Reduction of the aromatic nuclei contained in catalytic C-9 resins has also been accomplished in the molten state (66). Continuous downward concurrent feeding of molten resin (120°C softening point) and hydrogen to a fixed bed of an alumina supported platinum—mthenium (1.75% Pt—0.25% Ru) catalyst has been shown to reduce approximately 100% of the aromatic nuclei present in the resin. The temperature and pressure required for this process are 295—300°C and 9.8 MPa (lOO kg/cni2), respectively. The extent of hydrogenation was monitored by the percent reduction in the uv absorbance at 274.5 nm. 

There is an apparent paradox here that as the cooled cycle contains an irreversible process (constant pressure mixing), its efficiency might be expected to be lower than the original uncooled cycle. The answer to this paradox follows from consideration of all the irreversibilities in the cycle and we refer back to the analysis of Section 3.2.1.1, for the rational efficiency of the [CHT]ru cycle. The irreversibility associated with the heat supply is unchanged, as given in Eq. (3.3), but the irreversibility associated with the heat rejection between temperatures T(, and T) = Ta becomes... 

To accelerate the polymerization process, some water-soluble salts of heavy metals (Fe, Co, Ni, Pb) are added to the reaction system (0.01-1% with respect to the monomer mass). These additions facilitate the reaction heat removal and allow the reaction to be carried out at lower temperatures. To reduce the coagulate formation and deposits of polymers on the reactor walls, the additions of water-soluble salts (borates, phosphates, and silicates of alkali metals) are introduced into the reaction mixture. The residual monomer content in the emulsion can be decreased by hydrogenizing the double bond in the presence of catalysts (Raney Ni, and salts of Ru, Co, Fe, Pd, Pt, Ir, Ro, and Co on alumina). The same purpose can be achieved by adding amidase to the emulsion. 

The isomerization of 1-butene to cis- and trans- 2-butene onPd/C/Nafion and Pd-Ru/Nafion electrodes is one of the most remarkable and astonishing electrochemical promotion studies which has appeared in the literature.39,40 Smotkin and coworkers39,40 were investigating the electrocatalytic reduction of 1-butene to butane on high surface area Pd/C and Pd-Ru cathodes deposited on Nafion 117 when, to their great surprise, they observed at slightly negative overpotentials (Fig. 9.31) the massive production of 1-butene isomerization, rather than reduction, products, i.e. cis- and trans-2-butenes. This is extremely important as it shows that electrochemical promotion can be used also to enhance nonredox catalytic reactions such as isomerization processes. 

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