Photodissociation of Stilbene Radical Cation

Article abstract of DOI:10.1021/ja00370a006

The fragmentation of stilbene radical cation has been studied with ion cyclotron resonance (ICR) photodissociation spectroscopy.The trans radical cation appears to be formed by electron impact of either the cis or trans neutral based on a comparison of dissociation cross sections with absorption spectra.Dissociation occurred by loss of H, H2, or CH3.The fragmentation via loss of a hydrogen atom or molecule can be explained by photoinitiated trans-cis isomerization and electrocyclic ring closure, processes analogous to those of those of the neutrals.Reaction pathways are discussed in terms of the Woodward-Hoffmann rules for ring closure in examining the involvement of electronically excited states in ion fragmentation.