Journal ArticleDOI
Excited-state quenching by proton-coupled electron transfer
Javier J. Concepcion,M. Kyle Brennaman,Jeremy R. Deyton,Natalia V. Lebedeva,Malcolm D. E. Forbes,John M. Papanikolas,Thomas J. Meyer +6 more
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TLDR
The protonated, reduced complex [Ru(bpy)2(bpzH•)]2+ functions as a H-atom reductant toward quinone or benzaldehyde with potential implications for net photochemistry and energy conversion.Abstract:
The emitting metal-to-ligand charge transfer (MLCT) excited state of [Ru(bpy)2(bpz)]2+ (bpy is 2,2‘-bipyridine; bpz is 2,2‘-bipyrazine) is reductively quenched by hydroquinone (H2Q) by proton-coupled electron transfer (PCET), most likely by concerted electron−proton transfer (EPT). The identity of the transient products ([Ru(bpy)2(bpzH•)]2+ and HQ•) and the kinetics of their formation and disappearance have been established by steady-state emission and time-resolved emission, absorption, and EPR measurements. The protonated, reduced complex [Ru(bpy)2(bpzH•)]2+ functions as a H-atom reductant toward quinone or benzaldehyde with potential implications for net photochemistry and energy conversion.read more
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Journal ArticleDOI
Base-induced phototautomerization in 7-hydroxy-4-(trifluoromethyl)coumarin.
Brittany C. Westlake,Jared J. Paul,Stephanie E. Bettis,Shaun D. Hampton,Brian P. Mehl,Thomas J. Meyer,John M. Papanikolas +6 more
TL;DR: The result is a tautomerization process occurring on the picosecond time scale in which the 1-methylimidazole base acts as a proton-transfer shuttle from the hydroxyl group to the carbonyl.
Journal ArticleDOI
Tuning Excited-State Reactivity by Proton-Coupled Electron Transfer
Han Li,Ming-Tian Zhang +1 more
TL;DR: The triplet state of benzophenone functionalized with a Brønsted acid (3 *BP-COOH) showed a more powerful oxidation capability over the simple tripletstate of benz phenophenone (3 *.BP).
Journal ArticleDOI
Role of Hydrogen Bonding in Photoinduced Electron-Proton Transfer from Phenols to a Polypyridine Ru Complex with a Proton-Accepting Ligand.
TL;DR: Electron-proton transfer from phenols to a triplet metal-to-ligand charge transfer (MLCT)-excited Ru polypyridine complex containing an uncoordinated nitrogen site, 1(T), can be described by a kinetic model and evidence for the formation of a precursor H-bonded complex between the reactants is provided.
Journal ArticleDOI
Visible-light-driven photoreactions of [(bpy)2Ru(II)L]Cl2 in aqueous solutions (bpy = bipyridine, l = 1,2-bis(4-(4'-methyl)-2,2'-bipyridyl) ethene).
TL;DR: It is proposed that a Ru(III) radical intermediate is formed by photoinduced excited-state electron and proton transfer, which initiates the dimerization, which can also undergo photochemical degradative reductions.
Journal ArticleDOI
Single- versus Multi-Proton-Coupled Rydberg-State Electron Transfer in Amine Clusters
TL;DR: Amino fragments are well-known to exist widely in biological systems and their protonated forms are inclined to trap electrons and form Rydberg radicals (−NH3•) in the electron-excess system as discussed by the authors.
References
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