Sunlight-Driven Dehydrogenative Oxidation Photocatalysis by a Mononuclear Complex Acting as both Chromophore and Catalyst

Molecular and supported ruthenium complexes as photoredox oxidation catalysts in water

“…The electrochemical study displays two 1e − /1 H + processes, then the two one-electron processes in the mechanism could be responsible for the lack of total selectivity in the photooxidation of primary alcohols. 25…”

“…The electrochemical study displays two 1e − /1 H + processes, then the two one-electron processes in the mechanism could be responsible for the lack of total selectivity in the photooxidation of primary alcohols. 25 Under these conditions of reaction, we performed a preliminary photooxidation test using trans-β-methylstyrene as substrate. It was found that 44% of the trans-β-methylstyrene was converted, and only diol was obtained as a product of oxidation.…”

“…[16][17][18][19][20] The most studied ruthenium complexes have been [Ru(bpy) 3 ] 2+ 21,22 and derivatives 23,24 as photocatalysts; however, very few ruthenium aqua complexes have been tested both as a photosensitizer and a catalyst in the oxidation of organic substrates in water. 25 From the perspective of sustainability and industrial applicability, the grafting of homogeneous catalysts on solid supports with a high surface is a good approach. Graphene and derivatives have appreciable interest due to their low cost, high surface area, excellent thermal and chemical stability and rich surface chemistry.…”

“…16–20 The most studied ruthenium complexes have been [Ru(bpy) 3 ] 2+ 21,22 and derivatives 23,24 as photocatalysts; however, very few ruthenium aqua complexes have been tested both as a photosensitizer and a catalyst in the oxidation of organic substrates in water. 25…”

Enhancing Photoredox Catalysis in Aqueous Environments: Ruthenium Aqua Complex Derivatization of Graphene Oxide and Graphite Rods for Efficient Visible-Light-Driven Hybrid Catalysts

“…Generally, as the π-acceptor character of the ligands increases, it stabilizes the Ru II species, resulting in higher Ru III/II potentials and lower Ru IV/III potentials. On the basis of the photocatalytic and electrochemical results, the proposed mechanism is consistent with the formation of high-valent Ru(IV)O species formed via PCET processes (see Figure ) and it is in agreement with the proposed mechanism by Rocha et al The [Ru II –OH 2 ] 2+ complex was first activated by visible light to form the excited [Ru II –OH 2 ] 2+ * species. Then, the oxidative quenching by the sacrificial acceptor S 2 O 8 2– generates the [Ru III –OH] 2+ species that disproportion to [Ru IV =O] 2+ and [Ru II –OH 2 ] 2+ both thermodynamically more stable, with the oxo complex being the one that oxidizes the corresponding alcohol.…”