ESR and ENDOR Studies of Ion Formation in X‐Irradiated Thiodiglycollic Acid

Single crystals of thiodiglycollic acid were irradiated at 4.2°K and examined by ESR and ENDOR spectroscopy. The paramagnetic absorption consists of two components which are attributed to positive and negative ions of thiodiglycollic acid. The negative ion is formed by electron attachment to an oxygen of the carboxyl group. The unpaired spin density is localized primarily on the carbon atom of the carboxyl group. The positive ion has its charge and unpaired spin density localized primarily on the sulfur atom.