REACTIONS OF HE3H+ IONS WITH GASEOUS HYDROCARBONS .4. CYCLOBUTANE CYCLOPENTANE AND CYCLOHEXANE

Gaseous carbonium ions were produced from the protonation of cyclobutane, cyclopentane, and cyclohexane with helium tritide molecular ions, obtained from the β decay of molecular tritium. A fraction of the excited carbonium ions formed from the exothermic protonation are collision stabilized at pressures ranging from 100 to 400 Torr, and yield in all systems stabilized cycloalkanium ions. The latter can partially rearrange to the isomeric linear carbonium ions. The results obtained provide direct evidence for the existence of the gaseous cyclo butanium, cyclopentanium, and cyclohexanium ions. © 1969, American Chemical Society. All rights reserved.