Ion–Molecule Reactions of CH4–CD4 Mixtures at High Pressures

Ion–molecule reactions in mixtures of CH4 and CD4 at pressures up to about 0.65 torr have been carried out in a single ion source of a quadrupole mass filter. From the isotope distribution in the ethyl ions, it is evident that randomization occurs in the complex of methyl ions with methane. There is no evidence for reaction of ethyl ion with methane. Similarly, methane ions react with methane to form CH5+, CH4D+, CD4H+, and CD5+. The ratios of products are very nearly what would be expected from reactions of methane ion with methane rather than from transfer of protons and deuterons from methanium ion. H and D atoms appear to be transferred at equal rates but deuterons are transferred at only about six‐tenths the rate of transfer of protons.