▪ Abstract Proton-coupled electron transfer (PCET) is an important mechanism for charge transfer in a wide variety of systems including biology- and materials-oriented venues. We review several are...

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Proton-Coupled Electron Transfer

A hydrogen bond, X-H...A, is an interaction wherein a hydrogen atom is attracted to two atoms, X and A, rather than just one and so acts like a bridge between them. This attraction always increases with increasing electronegativity of X and A, and in the classical view all hydrogen bonds are highly electrostatic and sometimes even partly covalent. Gradually, the concept of a hydrogen bond became more relaxed to include weaker interactions, provided some electrostatic character remains. In the limit, these weak hydrogen bonds have considerable dispersive-repulsive character and merge into van der Waals interactions. A great variety of hydrogen bonds are observed in the solid state and the aim of this article is to highlight some features common to all these bonds and further to suggest that the term hydrogen bridge is perhaps a better descriptor for them. Such a description recognizes an interaction without borders and one that admits of much variation in its relative covalent, electrostatic, and van der Waals content.

Hydrogen bridges in crystal engineering: interactions without borders.

Photophysics, photochemistry and solar energy conversion with tris(bipyridyl)ruthenium(II) and its analogues

Molecular Catalysts for Water Oxidation

Ruthenium-Catalyzed Reactions for Organic Synthesis.

Preparation des complexes [(trpy) (bpy) M-OH 2 ] 2+ (M=Ru, Os). Etude de leurs proprietes redox en solution aqueuse

Redox and spectral properties of monooxo polypyridyl complexes of ruthenium and osmium in aqueous media

The kinetics of oxidation of p-/sup -/O/sub 2/CC/sub 6/H/sub 4/CH(CH/sub 3/)/sub 2/,p-/sup -/O/sub 2/CC/sub 6/H/sub 4/CH/sub 2/CH/sub 3/,and p-/sup -/O/sub 2/CC/sub 6/H/sub 4/CH/sub 3/ by Ru(trpy)(bpy)O/sup 2 +/ (trpy is 2,2',2''-terpyridine; bpy is 2,2'-bipyridine) to the corresponding ..cap alpha.. alcohols in water and of C/sub 6/H/sub 5/CH(CH/sub 3/)/sub 2/ and C/sub 6/H/sub 5/CH/sub 3/ by Ru(bpy)/sub 2/(py)O/sup 2 +/ in acetonitrile have been studied. The following conclusions are drawn from kinetics data obtained spectrophotometrically: (1) Rate constants increase with increasing alkyl substitution; for the carboxylates in water at 24.3/sup 0/C, k = 12.2 +/- 1.2, 3.4 +/- 0.3, and 0.43 +/- 0.04 M/sup -1/ s/sup -1/ in the order shown above. (2) Rate constants decrease dramatically for the reactions in acetonitrile; k(24.3/sup 0/C) = 0.026 +/- 0.003 M/sup -1/ s/sup -1/ for isopropylbenzene. (3) In water, rate constants are independent of added O/sub 2/ or of changes in ionic strength. (4) In acetonitrile the added nucleophiles water, tert-butyl alcohol, or bromide ion enter the rate law directly in terms first order in added nucleophile. From the temperature dependence of k for the oxidation of p-/sup -/O/sub 2/CC/sub 6/H/sub 4/CH(CH/sub 3/)/sub 2/, ..delta..H/sup + +/ = 7 +/- 1 kcal/mol andmore » ..delta..S/sup + +/ = -32 +/- 4 eu. It is concluded that the redox step for the reactions involves a two-electron, hydride ion transfer step. The reactions occur by a template mechanism in that oxo group transfer from Ru to the substrate does not occur and the added oxygen atom must come from the solvent, p-/sup -/O/sub 2/CC/sub 6/H/sub 4/CH(CH/sub 3/)/sub 2/ (-H:/sup -/; +H/sub 2/O) ..-->.. p-/sup -/O/sub 2/CC/sub 6/H/sub 4/C(OH)(CH/sub 3/)/sub 2/. The solvent or added nucleophile (in acetonitrile) is directly involved in the redox step, apparently by assisting the loss of the hydride ion by electron pair donation.« less

Kinetics and Mechanism of Oxidation of Aromatic Hydrocarbons by Ru(trpy)(bpy)O2

Mechanisms of oxidation of 2-propanol by polypyridyl complexes of ruthenium(III) and ruthenium(IV)

Chemically Catalyzed Net Electrochemical Oxidation of Alcohols, Aldehydes, and Unsaturated Hydrocarbons Using the System (trpy)(bpy)Ru(OH2)2+/(trpy)(bpy)RuO2+

Utilisation du complexe cationique [Ru(IV)(O)(terpyridine)(bipyridyle)] comme catalyseur pour l'oxydation electrocatalytique d'alcools, aldehydes, cyclohexanones, toluene dans des solutions aqueuses

Novel electrocatalytic procedure for the oxidation of alcohols, aldehydes, cyclic ketones, and carbon-hydrogen bonds adjacent to olefinic or aromatic groups

Mark S. Thompson

Papers

Redox and spectral properties of monooxo polypyridyl complexes of ruthenium and osmium in aqueous media

Kinetics and Mechanism of Oxidation of Aromatic Hydrocarbons by Ru(trpy)(bpy)O2

Mechanisms of oxidation of 2-propanol by polypyridyl complexes of ruthenium(III) and ruthenium(IV)

Chemically Catalyzed Net Electrochemical Oxidation of Alcohols, Aldehydes, and Unsaturated Hydrocarbons Using the System (trpy)(bpy)Ru(OH2)2+/(trpy)(bpy)RuO2+

Novel electrocatalytic procedure for the oxidation of alcohols, aldehydes, cyclic ketones, and carbon-hydrogen bonds adjacent to olefinic or aromatic groups