An electron spin resonance study of triplet radical pairs in single crystals of X-irradiated L-ascorbic acid at 77 K

Abstract

Single crystals of L-ascorbic acid have been irradiated and investigated at 77 K. The signals due to triplet radical pairs were observed. Three radical pairs, separated within the pair by 5.07, 6.28 and 8.46 Å were interpreted. The radicals which form the pairs are of the same type as those studied previously at room temperature as free radicals and published elsewhere. The location of the three types of radical pairs in the crystal was found by the comparison of the experimental results with crystal data. There are some signals arising from other radical pairs. It was not possible to follow the lines over a sufficient range of orientations to make an interpretation.