Ion-molecule reactions in Trihalo- and Tetrahalo-methanes

Abstract

The ion-molecule reactions of eight highly halogenated derivatives of methane were studied in the gas phase using a mass spectrometer operated at high pressures. The compounds studied were CHCl₃, CHCl₂F, CHClF₂, CHF₃, CCl₄, CCl₂F₂, CClF₃, and CF₄. These ionic systems were found to be less reactive than those of methane or the methyl and methylene halides. The main reactions observed were described as being halide ion transfer processes. The energy dependence of the cross sections and the rate coefficients of the reactant ions were determined.  Many rate coefficients for reactions between ions and polar molecules were found to be independent of the ion energy. Brief studies of the negative spectra at high pressures were also made.