Electron spin resonance studies. Part XXX. One-electron reduction of carbonyl-containing compounds by the radicals ·CO₂H, ·CO₂^–, and ·CMe₂·NH₂

Abstract

The following carbonyl compounds undergo one-electron reduction by the radicals ·CO2H, ·CO2–, or ·CMe2·NH2 to give species which have been characterised by their e.s.r. spectra; acetaldehyde, propionaldehyde, acetone, glyoxal, biacetyl, pyruvaldehyde, ethyl pyruvate, pyruvic acid, furmaric acid, maleic acid, and diethyl maleate. The dependence of the spectra on pH reveals the occurrence of acid-base equilibria for some of the radicals, and there is also evidence that some of the radicals undergo interconversion between tautomeric forms; the behaviour of fumaric and maleic acid, and the differences between the two compounds, are particularly notable in these respects.