The electron spin resonance of gamma and ultraviolet irradiated tetrabutylammonium halides NX (X=I,Cl,Br), tetrabutylammonium hydrogen sulfate NHSO, tetrabutyl-ammonium periodate NIO, and ultraviolet photolyzed tetramethylammonium iodide, (CHNI, and tetramethylphosphonium iodide, (CHPI have been investigated between 140 and 350 K. The gamma and ultraviolet irradiation damage centers in tetrabutylammonium compounds were attributed to CH-CH—CH—CH, radicals, and ultraviolet photolysis damage centers in tetramethylammonium and phosphonium iodides were attributed to C radicals. The g values of both radicals are found to be isotropic and g = 2.0030 and 2.0037 respectively to the methylallyl and the methyl radicals. The hyperfine coupling constants of the free electron to the protons in the radicals are reported and discussed. © 1992, Taylor & Francis Group, LLC. All rights reserved.