First Micelle‐Free Photoredox Catalytic Access to Hydrated Electrons for Syntheses and Remediations with a Visible LED or even Sunlight

: Hydrated electrons are super-reductants, yet can be generated with visible light when two photons are pooled, most efficiently through storing the energy of the first photon in a radical pair formed by the reduction of an excited catalyst by a sacrificial donor. All previous such systems for producing synthetically useable amounts of hydrated electrons with an LED in the visible range had to resort to compartmentalization by SDS micelles to curb the performance-limiting recombination of the pair. To overcome micelle-imposed constraints on sustainability and applications, we have instead attached carboxylate groups to a ruthenium (tris)bipyridyl catalyst such that its pentaanionic radical strongly repels the dianionic radical of the bioavailable donor urate. We have explored the influence of the Coulombic interactions on the electron generation by a time-resolved study from microseconds to hours, including for comparison the unsubstituted complex, which forms a monocationic radical, with and without SDS micelles. The new homogeneous electron source is best with regard to stability and total electron output; it has a broader synthetic scope because it does not entail micellar shielding of less hydrophilic compounds, which particularly facilitates cross-couplings; and it tolerates supramolecular containers as carriers of water-insoluble substrates or products. As an application in the field, we demonstrate the solar remediation of a recalcitrant chloro-organic bulk chemical.