Diatomic-Ion—Molecule Reactions: N2+–N2, CO+–CO, and O2+–O2

Abstract

New channels of reaction have been found in the N₂⁺–N₂ and CO⁺–CO ion—molecule systems. These processes which account for a major fraction of the total ion—molecule collision cross section yield, respectively, N⁺ and C⁺ ions. A study of the energetics of the respective processes leads to the conclusion that stable neutral N₃ and CO₂ are also formed. A value of approximately 6 eV is obtained for the energy of dissociation of N₃ radicals into N and N₂. Minor reaction products N₃⁺ and C₂O⁺ observed in earlier studies of the N₂⁺–N₂ and CO⁺–CO systems were also observed in this work. In the O₂⁺–O₂ system only O₃⁺ ions were detected and in relatively minor yields. Production of O₃⁺ rather than O⁺ is energetically favored. The relatively small yield of O₃⁺ is shown to be a result of the energetics of the system which tends to cycle O₃⁺ back to O₂⁺ and O atoms which are not detected in the mass‐spectrometer analysis of reaction products. In all three systems over‐all reaction cross sections were found to be in good agreement with theoretical values of ion—molecule collision cross sections when sufficient energy is available and all channels of reaction are taken into consideration.