A field ionization and collisionally activated dissociation/charge stripping study of some [C₉H₁₀]^+˙ ions

Abstract

Abstract The extent of isomerization of [C 9 H 10 ] +˙ ions, with lifetimes of approximately 10 −11 and 10 −6 s has been investigated using field ionization, collisionally activated dissociation and charge stripping techniques. The [C 9 H 10 ] +˙ ions which were investigated included the molecular ions of α‐methylstyrene, β‐methylstyrene, o ‐methylstyrene, m ‐methylstyrene, p ‐methylstyrene, indan, cyclopropylbenzene, allylbenzene and the product of water loss from 3‐phenylpropanol. The field ionization spectra of all the C 9 H 10 hydrocarbons were different indicating that isomerization to a common ion structure had not occurred to a measurable extent for ions with lifetimes of approximately 10 −11 s. Collisionally activated dissociation and charge stripping results indicated that most of the [C 9 H 10 ] +˙ ions continued to maintain unique ion structures (or mixtures of structures) at ion lifetimes of 10 −6 s. Possible exceptions are the [C 9 H 10 ] +˙ ions from allylbenzene and cyclopropylbenzene which gave indistinguishable collisionally activated dissociation and charge stripping spectra.