Gas-Phase Diels-Alder Reaction of the o-Quinodimethane Radical Cation and Neutral Styrene

Article abstract of DOI:10.1021/jo00157a027

The collision complex formed in the ion-molecule reaction of o-quinodimethane radical cation and neutral styrene was investigated by using mass spectrometry/mass spectrometry (MS/MS) techniques.The reaction was conducted in a high-pressure chemical-ionization source, where the reagents were ionized by low-energy charge exchange and the reaction products were collisionally stabilized.The collision complex was shown to have the structure of 2-phenyltetralin through the use of deuterium labeling and direct comparison with the properties of reference radical cations.These results establish the structural integrity of low-energy o-quinodimethane radical ions and are evidence for a Diels-Alder reaction mechanism.