Observation of “Intramolecular” Ion-Molecule Reactions within Ionized Hetero Clusters of Methyl Chloride-Acetone

Upon ionization,^1,2large polyatomic molecules (such as halo-carbons^3-5 are usually excited and the ions undergo unimolecular decay. One might therefore expect a nascent cluster ion to fragment simply into a small ion and neutral molecular constituents, i.e., the “solvent” molecules. In contrast, as reported for methyl halide clusters,^6,7extensive bond reformation (not merely “evaporation”) can take place within the ionized clusters. This suggests that bimolecular (and possibly termolecular) reactions are occurring rapidly within a cluster ion. The major pathways observed can indeed be accounted for by known bimolecular ion-molecule reactions, previously studied by ICR⁸⁻¹²(and other methods).