The mechanisms of some positive and negative ion-molecule reactions have been determined by a quantitative ion cyclotron double-resonance technique with isotopically labelled reactants. Four types of mechanism were elucidated: charge transfer, ion transfer, atom abstraction and complex formation. Thus, charge transfer is shown to be the only major reaction channel in the systems CO+ + CO2, SO- + SO2, and O- + NO2, while in the system Cl2- + Cl2 CO ion transfer is the main mechanism, and complex formation with oxygen-atom scrambling is the major channel in O- + N2O. The experimental results also point out cases where the reaction proceeds by more than one mechanism as, for example, in the reaction system H2O+ + H2O.
|Number of pages||10|
|Journal||International Journal of Mass Spectrometry and Ion Physics|
|State||Published - Jan 1981|