Gas phase reactions of some positive ions with atomic and molecular oxygenand nitric oxide at 300 K

Rate coefficients and product ion distributions have been determined for th e reactions of HCNH+, HC3N+, H2C3N+, H2O+, N-2(+), HCO+, and HCO2+ with O a toms in a selected ion flow tube at 295 +/- 5 K. Only two of these ions, HC 3N+ and N-2(+), were found to react with atomic oxygen, and both ions exhib ited multiple reaction channels. Reactions with O atoms may be relevant to synthetic processes occurring in some interstellar clouds. Because of the a pplication of the N + NO titration to determine O atom concentrations, the rate coefficient and product distribution for the reaction of each ion with O-2 and NO was also measured.