K. Butkiewicz
Oct 1, 1972
Citations
0
Influential Citations
4
Citations
Journal
Journal of Electroanalytical Chemistry
Abstract
Summary Electroreduction of isomeric 1-(3-pyridyl)-3-[2(3 or 4)-pyridyl]-2-propen-1-ones and 1-(2-pyridyl)-3-[2(or 4)-pyridyl]-2-propen-1-ones on the DME is described. The experiments were made in mixtures of Britton-Robinson buffers and ethanol (1: 1) at pH 2.6–12.6 and in 0.175 mol l −1 (C 4 H 9 ) 4 NI in 75% dioxane. The reduction of the compounds was much the same as described for chalcone and other similar depolarizers (see Part I). Two main two-electron reduction waves were obtained which corresponded to the reduction, first of the ethylenic linkage, and second of the carbonly group to the corresponding dihydroderivatives and secondary alcohols, respectively. The second reduction wave was separated into two steps differing considerably in E 1/2 potential. The splitting of the first reduction wave into two steps was much less distinct and observable only in alkaline medium. All the compounds investigated displayed marked surface activity, confirmed by drop-time curves and a.c. polarography. The Hammett-Taft constants σ x * were calculated for 2- and 3-pyridoyl groups from polarographic data as+1.85 and +1.80, respectively.