Unstable intermediates. Part LIII. An electron spin resonance study of the radical formed by addition of a hydrogen atom to pyridinium ion

Abstract

After exposure of pyridinium hydrochloride in solid, anhydrous hydrogen chloride to γ-rays a well-resolved e.s.r. spectrum was obtained which has been shown by study of the corresponding radicals formed from certain deuteriated pyridines to be due to a radical produced by addition of a hydrogen atom to the 4-position of the pyridinium cation. The results are compared with those for the isoelectronic cyclohexadienyl radical.