Electrochemically-mediated Photoredox Catalysis emerged as a powerful synthetic technique in recent years, overcoming fundamental limitations of electrochemistry and photoredox catalysis in the single electron transfer activation of small organic molecules. However, the mechanism of how photoexcited radical ion species with ultrashort (picosecond-order) lifetimes could ever undergo productive photochemistry has eluded synthetic chemists. We report tri(para-substituted)biarylamines as a tunable class of electroactivated photocatalysts that become superoxidants in their photoexcited states, even able to oxidize molecules (such as dichlorobenzene and trifluorotoluene) beyond the solvent window limits of cyclic voltammetry. Furthermore, we demonstrate that precomplexation not only permits the excited state photochemistry of tris(para-substituted)biarylaminium cations, but enables and rationalizes the surprising photochemistry of their higher-order doublet (Dn) excited states.

中文翻译：

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空穴介导的光氧化还原催化：三（对位取代）联芳基铵自由基阳离子可调谐，预配合和强效光氧化剂

近年来，电化学介导的光氧化还原催化作为一种​​强大的合成技术应运而生，克服了在有机小分子的单电子转移活化中电化学和光氧化还原催化的基本限制。然而，具有超短（皮秒级）寿命的光激发自由基离子物种如何能够经历生产性光化学反应的机理，已被合成化学家所迷惑。我们报道了三（对位取代）联芳胺作为一种可调节的电活化光催化剂，在其光激发态变成超氧化剂，甚至能够氧化超出循环伏安法溶剂范围的分子（如二氯苯和三氟甲苯）。此外，