Infrared spectra of the molecular ions and radicals produced by proton radiolysis of carbon tetrachloride in argon during condensation at 150K

Samples of CCl4 and its carbon-13- or bromine-substituted counterparts at high dilution in argon were deposited at 150K during simultaneous 2.0-keV proton beam irradiation. New infrared absorptions at 1037, 1020, 927, 898, 746, 502, 374, 290, and 242 cm-1 are attributed to CCl4 radiolysis products and ion-molecule reaction products. The 898- and 746-cm-1 bands are due, respectively, to the CCl3 and CCl2 chemical intermediates. The 1020-, 927-, 502-, 374-, and 290-cm-1 bands, which disappear upon photobleaching and neutralization with thermal electrons, are assigned to the matrix-isolated positive molecular ions CCl3+, CCl2+, Cl3+, Cl2CCl2+, and Cl4+, respectively. The 242-cm-1 absorption is likely due to Cl3- perturbed by a large cation. The 1037-cm-1 band is due to a CCl3+ vibration in an electrically neutral species, presumably CCl3+Cl-. The fate of the bombarding proton is demonstrated by the observation of CHCl3 and HCl2-, and in deuteron experiments, by the appearance of CDCl3 and DCl2-. (U.S.)