High level time‐dependent density functional theory (TD‐DFT) computational modeling of coumarin dyes has been exploited for guiding the design of effective photocatalysts (PCs). A library of coumarins were investigated from the theoretical point of view and photophysical/electrochemical properties (absorption and emission spectra, E₀₀, oxidation and reduction potentials) were evaluated. Comparison with literature values reported for a few candidates has been used for assessing the level of theory. On the basis of the results obtained, new strongly reducing PCs [E_ox(PC^.+/PC*)=−2.1 – −2.0 V vs SCE] were discovered. Through the computational study of structure‐properties relationships, a number of coumarins derivatives have been synthesized and evaluated in the pinacol coupling of aldehydes as the model reaction. The new organic photoredox catalysts show experimental photophysical and electrochemical data in accordance with the ones predicted by calculation, with excited state reduction potentials surpassing those of highly reducing transition metal‐based PCs. A careful investigation of their behavior as PC has revealed crucial issues that need to be taken into consideration in the general photoredox catalysis, shedding light on the use of these PC in the pinacol, as well as, in other photoredox reactions.

中文翻译：

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量身定制的用于光氧化还原催化的香豆素染料：计算，合成和电子性质

香豆素染料的高级时变密度泛函理论（TD-DFT）计算模型已被用来指导有效光催化剂（PC）的设计。从理论角度研究了香豆素库，并评估了光物理/电化学性质（吸收和发射光谱，E ₀₀，氧化和还原电势）。与报告的一些候选人的文献价值进行比较已用于评估理论水平。根据获得的结果，新的还原性强的PC [ E _ox（PC ^。+/PC*)=−2.1 – −2.0 V vs SCE]。通过对结构-性质关系的计算研究，已经合成了许多香豆素衍生物，并在甲醛的频哪醇偶联中作为模型反应进行了评估。新型有机光氧化还原催化剂根据计算预测的数据显示了实验光物理和电化学数据，其激发态还原电势超过了高度还原的过渡金属基PC的电势。对它们作为PC的行为进行的仔细研究表明，在一般的光氧化还原催化中需要考虑到一些关键问题，从而阐明了频哪醇以及其他光氧化还原反应中这些PC的使用。