Multiple substituent effects in the CC reduction of phenyl styryl ketones: cyclic voltammetry as a tool

Cyclic voltammetric studies on 16 mono- and disubstituted phenyl styryl ketones (PSKs) or chalcones have been performed. Multiple substituent effects on the first reduction potential (E) were analysed with the help of the Hammett equation and the ρ values were evaluated for various substituents in one ring for each substituent in the other ring and vice versa. An interactive Gibbs energy relationship was applicable to this system. The reduction of alkenyl instead of carbonyl is expected to give similar values for cross-interaction constants qx and qy and the same were obtained (qx=−0.6720 and qy=−0.6710).