Experimental and Computational Elucidation of Protic Redox Reaction Mechanisms

Molecular design of redox‐active species for applications such as redox sensing, energy storage and chemical synthesis hinges on reliable methods for predicting redox potentials. Protic redox potentials are especially challenging to model, because they are mechanism‐dependent; they may proceed via multiple pathways and/or yield a range of different products, depending on experimental conditions. Experimental elucidation of these mechanisms is challenging and time‐consuming, but computational modelling may offer a convenient and cost‐effective alternative. However, careful quantification of computational and experimental uncertainties is required for robust mechanistic assignments. In this work, we apply a new computational procedure for estimating protic redox potentials with associated computational uncertainties and show that it may be used to assign mechanisms for a diverse range of redox species and processes, including reductive ring opening of benzoxadiazole; irreversible reduction of dinitrobenzoic acid and Orange G and reversible oxidation of their reduction products; reversible oxidation and irreversible reduction of Nitroso‐R; and reversible reduction of Basic Red 5.