Doubly charged ions. Mass spectra and appearance energies for small hydrocarbons

The mass spectra of doubly charged ions of the hydrocarbon molecules ethene, difluorethene, propane, propene, cyclopropane, propyne, allene, 1,3-butadiene, 2-butene ( cis ), benzene, and cyclohexane have been recorded. For some of them, appearance energies of doubly charged fragments could be measured. In the case of benzene, we even observed the triply charged molecular ion.