Kinetic electron spin resonance spectroscopy. Part I. The photoreduction of biacetyl and pyruvic acid in organic solvents

Abstract

The kinetics of the photoreduction of biacetyl and pyruvic acid in a number of solvents have been studied at room temperature by use of e.s.r. spectroscopy to monitor the concentration of the intermediate radicals ·CMe(OH)·COR.

Kinetic rate equations have been established in accord with the assumption that the observed radicals are formed by abstaction of H from the solvents by triplet-state molecules. Rates of radical termination reactions in isopropyl alcohol, cyclohexene and di-isopropyl ether have been measured by the rotating sector technique and by direct observation of the rate of decay, a computer being used for averaging transients.