Scientific news INC/CNRS: a photoredox catalyst that accumulates charges under visible light

Photoredox catalysis, which uses visible light to promote a chemical reaction, is emerging as a major tool for more sustainable organic synthesis. Another aim is to store solar energy in the form of chemical bonds. A photoredox catalyst requires the association of a photoactive antenna, which produces charges under the action of photons, with a redox catalyst capable of accepting/releasing these photogenerated charges to operate the desired redox reactions. Most of these reactions involve multi-electronic processes, whereas photosensitizers generally produce single-electronic charge separation processes. Only a few photoactive molecular systems with a charge accumulation site have been described to date. The development of an integrated system capable of absorbing visible light energy, accumulating charges and finally using them in a catalytic process is therefore of great interest.

Chemists at the Paris Institute of Molecular Chemistry (CNRS/Sorbonne Université) and the Marseille Institute of Molecular Sciences (CNRS/Aix Marseille Université/Centrale Méditerranée) have recently synthesized such a system, based on a hybrid organic/inorganic compound consisting of a functionalized polyoxometalate and a copper complex. Under visible light irradiation, this molecular edifice is capable of storing up to three reducing equivalents. The site of the reduction process is discussed on the basis of physico-chemical measurements and theoretical calculations. Chemists have demonstrated the power of this photoredox system with the photocatalytic generation of CF3 (trifluoromethyl)-type radicals, with direct applications in organic synthesis for the pharmaceutical and food industries. These results are published in the Journal of the American Chemical Society.

Under light irradiation, the organic/inorganic hybrid compound consisting of a functionalized polyoxometalate and a copper complex is capable of storing up to three reducing equivalents. Maylis Orio

Référence

Multi-Electron Visible Light Photoaccumulation on a Dipyridylamine Copper(II)−Polyoxometalate Conjugate Applied to Photocatalytic Generation of CF3 Radicals
Weixian Wang, Lise-Marie Chamoreau, Guillaume Izzet, Anna Proust, Maylis Orio & Sébastien Blanchard
JACS 2023
https://doi.org/10.1021/jacs.3c01716

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