Isomeric [C 7 H 8 ] + ˙ and [C 7 H 7 ] + ions

The photofragmentation of an equimolar mixture of cycloheptatriene and [1, Me‐ 13 C 2 ]toluene was studied with photons of wavelength 488 nm in order to obtain a direct comparison between the two isomers. The idea was to check the extent to which these photons could be used as a probe to study the fragmentation processes. Whenever feasible, the data were treated by a kinetic scheme and rate constants were obtained by a non‐linear regression. It could be shown that the decay of both isomers follows a time behaviour described by two exponential decays. Evidence is presented that the faster decay leads to the benzyl ion. The photofragmentation of the [C 7 H 7 ] + ions follows a complex behaviour that can be superimposed by selective ion–molecule reactions.