An ESR Study of the Radicals in X-Irradiated L-α-Amino-n-Butyric Acid HCl Containing 1.5% L-Cysteine HCl

After X-irradiation at room temperature, the radicals in L-α-amino-n-butyric acid HCl are ${\rm CH}_{3}{\rm CH}_{2}{\rm CHCOOH}$. The β- and α-hyperfine constants are typical of those found in amino acid radicals. On annealing at temperatures near 100°C this carbon-centered radical in samples containing 1.5% cysteine converts to a perthiyl radical, ${\rm RCH}_{2}{\rm S}(1){\rm S}(2)$. The g-values for the perithiyl radical are 2.0024, 2.0257, and 2.0557. When the field is in the minimum g-value direction, the hyperfine splittings are 50 G for ^{33}{\rm S}(2)$ and 32 G for ^{33}{\rm S}(1)$.