Ion molecule reactions of carbon cluster ions with D2 and O2

Abstract

The ion/molecule chemistry of laser‐generated carbon cluster ions (C⁺_n; n=3–19) has been studied using Fourier transform mass spectrometry. The ion/molecule reactions of mass‐selected carbon cluster ions with D₂ and O₂ have been studied and reaction rates measured. Reactions of the primary product ions with D₂ and O₂ were also studied. The change in reactivity observed as a function of cluster size suggests a structural change from linear to monocyclic rings in the cluster ions between n=9 and 10. Evidence for the presence of two structural isomers for the C⁺₇ cluster ion has also been observed and has been attributed to the existence of both a linear and cyclic form of the ion. MNDO calculations have also been used to obtain structural and thermodynamic information on possible reactant and product ions in an attempt to explain the differences observed in the ion/molecule reactions. The results from collision induced dissociation studies of the carbon cluster ions are also discussed.