Electron spin resonance of an irradiated single crystal of maleic acid

Abstract
Electron spin resonance spectroscopy has been used to investigate radiation damage in an irradiated single crystal of maleic acid. At least two stable radicals are produced by the radiation. One of these radicals is probably HOOC-H2C-CH-COOH. Another species, possibly of the form HOOC-RCH-CH-COOH, has also been observed. Radical yields have been measured for the isomeric maleic and fumaric acids. The G-values are 0.1 for maleic acid and 0.06 for fumaric acid.