Electron spin resonance studies of elementary processes in radiation- and photo-chemistry. Part 10.—Carboxylic acid anhydrides at cryogenic temperatures

Abstract

The four carboxylic acid anhydrides, acetic, propionic, n-butyric and iso-butyric, γ-irradiated at 77 K, show e.s.r. spectra indicating the presence of acyl radicals and radicals formed by loss of H from the anhydride. The latter radicals are derived in part from simple alkyl radical precursors as may be adduced from experiments on thermal annealing of the irradiated samples. No evidence is found for the presence of trapped radical-anions or cations. Hydrogen atoms react with anhydrides at 77 K to give the same types of radicals that are formed during γ-radiolysis, though in different relative yields.