Theoretical calculation of reduction potentials

The reduction potential is a direct measure of the thermodynamic feasibility of an oxidation-reduction half reaction; and it is fundamentally important in many aspects of organic, bioinorganic, and environmental chemistry, as well as in biology and materials science. The design of rational strategies for tuning the redox properties of compounds depends on understanding the key molecular features that dictate the reduction potential. As an example, in environmental chemistry, chlorinated aliphatic compounds are common environmental contaminants due to their widespread use as solvents and degreasers and are known to degrade via a reductive dehalogenation [1,2]; the environmental persistence of these compounds has been found to correlate with their relative reduction potentials, and the computation and measurement of these quantities is therefore valuable for understanding structure-activity trends and the design of environmentally friendly derivatives of these compounds [1,3-8]. Similarly, in biochemistry, nitroxides are a class of kinetically stable free radicals that have been widely studied as potential antioxidants against reactive oxygen species, which can lead to tissue injury and even cell death; both oxidation and reduction processes involving nitroxides are biologically relevant [9-12], and the ability to predict the redox potentials of nitroxides with various substituents and those embedded in rings can help prioritize synthetic targets for potentially biologically relevant antioxidants [13,14].