Substituent effects on the reduction potentials of benzalacetophenones (chalcones): Improved substituent constants for such correlations

The reduction potentials of a set of 23 monosubstituted and 7 disubstituted benzalacetophenones (chalcones) are linearly correlated considerably better with the σⁿ values of van Bekkum, Verkade, and Wepster than with Hammett σ. Groups were found to exert the same effect upon the reduction potential irrespective of which ring they are located on. The data for monosubstituted benzalacetophenones can be used to predict the reduction potentials of disubstituted derivatives with good accuracy.