PROTON RADIOLYSIS OF $CHCl_{3}$ AND $CHBr_{3}$ AT HIGH DILUTION IN ARGON DURING CONDENSATION AT $15^{\circ} K$ - IR SPECTRA OF MOLECULAR IONS

Abstract

Matrix samples of chloroform and its deuterium and bromine analogs have been subjected to irradiation by a 2.0 keV proton beam during deposition with the products being trapped in an argon matrix at $15^{\circ} K$. Several infrared absorptions have been observed and assigned to a number of new molecular species. Extremely photosensitive bands observed at 652, 621, 593, and $570 cm^{-1}$ have been assigned to the $CHCl_{3}^{-}$, $CHC_{2}Br^{-}$, $CHClBr_{2}^{-}$, and $CHBr_{3}^{-}$ molecular anions, respectively. Absorptions at 998, 907, and $839 cm^{-1}$ which were decreased by operating an exposed bulb filament, have been attributed to the isolated cations $CHCl_{2}^{+}$, $CHClBr^{+}$ and $CHBr_{2}^{+}$. Bands stable to the bulb filament were observed at 1044, 988, and $898 cm^{-1}$ and were assigned to the $CHX_{2}^{+}(X^{-}$) species, and similar bands at 838, 795, and $735 cm^{-1}$ were assigned to the $CHX_{2}^{-}$ anions. In addition, bands attributable to the species $CX_{3}^{+}$, $CX_{3}^{+} (X^{-}$), $CHX_{2}$, and $HX_{2}^{-}$, which have been identified previously, were observed here as well.