An ESR study of chlorine containing radicals in x-irradiated N-chlorosuccinimide at 77 K

Three different radicals were identified by ESR studies in x-irradiated single crystals of N-chlorosuccinimide; radicals I and II, stable at 77 K and radical III, stable at 240 K. Radical I was identified as the previously reported sigma anion radical, ≳N-Cl−. Radical II was found difficult to saturate at 200 mW and was assigned to a chlorine atom interacting weakly with a nearby nitrogen with gz=2.008, gx=2.120, and gy=2.126. The chlorine and nitrogen hyperfine couplings were found to be Az=116.0, Ax=6.4, Ay=4.2 G, and Az=8.4, Ax=4.7 and Ay=4.4 G, respectively. At 240 K, radical III was formed by the abstraction of a ring proton from a neighboring N-chlorosuccinimide molecule when radical I decayed.