IR Laser-induced chemistry of some perhaloethene–silane mixtures at different single irradiating wavelengths

Abstract

TEA CO₂ laser-induced reactions in chlorotrifluoroethene–silane-1,2-dichlorodifluoroethene–silane, 1,1-dichlorodifluoroethene–silane, and 1,2-dichlorodifluoroethene–trimethylsilane mixtures at medium (4–19 Torr) and in chlorotrifluoroethene–silane and 1,2-dichlorodifluoroethene–silane mixtures at low (<1 Torr) pressures can be initiated by irradiation tuned to either perhaloethene or silane. The reaction progress at medium pressure and reaction products at low pressure depend on the particular wavelength employed. The former reactions are assumed to occur through reactive collision of both energized components in the mixture and have been shown to yield mostly tetrafluorosilane, trifluorosilane, hydrogen chloride, and other hydrocarbons. The latter are explained by multiphoton dissociation of the alkene into carbenes, subsequent reactions of these carbenes, and by 1,2-rearrangement of halogen in the transient CFCICF˙ radical produced upon C–Cl bond cleavage of the parent CFClCFCl compound. This reaction mechanism is in line with IR multiphoton decomposition of 1,2-dichlorodifluoroethene both in the absence and presence of chlorine and carbon monoxide.