36620-55-0Relevant articles and documents
Exceedingly Facile Ph-X Activation (X=Cl, Br, I) with Ruthenium(II): Arresting Kinetics, Autocatalysis, and Mechanisms
Miloserdov, Fedor M.,McKay, David,Mu?oz, Bianca K.,Samouei, Hamidreza,MacGregor, Stuart A.,Grushin, Vladimir V.
supporting information, p. 8466 - 8470 (2015/11/27)
[(Ph3P)3Ru(L)(H)2] (where L=H2 (1) in the presence of styrene, Ph3P (3), and N2 (4)) cleave the Ph-X bond (X=Cl, Br, I) at RT to give [(Ph3P)3RuH(X)] (2) and PhH. A combined experimental and DFT study points to [(Ph3P)3Ru(H)2] as the reactive species generated upon spontaneous loss of L from 3 and 4. The reaction of 3 with excess PhI displays striking kinetics which initially appears zeroth order in Ru. However mechanistic studies reveal that this is due to autocatalysis comprising two factors: 1) complex 2, originating from the initial PhI activation with 3, is roughly as reactive toward PhI as 3 itself; and 2) the Ph-I bond cleavage with the just-produced 2 gives rise to [(Ph3P)2RuI2], which quickly comproportionates with the still-present 3 to recover 2. Both the initial and onward activation reactions involve PPh3 dissociation, PhI coordination to Ru through I, rearrangement to a η2-PhI intermediate, and Ph-I oxidative addition.
Hydrogen Production from Ethanol catalysed by Group 8 Metal Complexes
Morton, David,Cole-Hamilton, David J.,Utuk, Imelda D.,Paneque-Sosa, Marguerita,Lopez-Poveda, Manuel
, p. 489 - 496 (2007/10/02)
Different strategies for the catalytic thermal production of hydrogen from ethanol are discussed and demonstrated using various Group 8 metal catalysts, in the presence of added base.Where the metal has a low affinity for carbon monoxide, e.g. in +, simple dehydrogenation of ethanol to ethanal and its aldol condensation products is observed.When the metal has a high affinity for CO, CO abstraction from the formed ethanol occurs and, as in reactions catalysed by or i3)3>, can poison the reaction.In some cases, the CO abstraction reaction can be used to promote the thermodynamically favourable reactionof formation of hydrogen, methane, and carbon monoxide; although irradiation with visible light is often required to release the carbon monoxide from the metal centre e.g. i3)2> in the absence of base.Finally, in catalytic reactions carried out in the presence of base, water-gas shift type chemistry is observed in reactions catalysed by Cl, so that ethanol can be converted into 2H2, Ch4, and CO2.In the cases of , rates of hydrogen production of >100 catalyst turnovers h-1, corresponding to >1 l per litre of catalyst solution per hour can readily be sustained over long periods.The role of base in, and the mechanisms of , these interesting reactions are discussed; as are synergistic effects and reasons for the success of Cl and as catalysts for hydrogen production.
New Synthesis and Molecular Structure of Potassium Trihydridotris(triphenylphosphine)ruthenate
Chan, Albert S. C.,Shieh, Huey-Sheng
, p. 1379 - 1380 (2007/10/02)
A convenient, high yield method for the synthesis of ruthenium hydrides, including anionic ruthenium hydrides, has been developed; the molecular structure of potassium trihydridotris(triphenylphosphine)ruthenate (2) complexed with 18-crown-6-ether has been determined by single crystal X-ray diffraction.
