Formation and dissociation of triply charged fragment ions of benzene

Electron impact ionization of small singly charged hydrocarbon ions was app lied to produce and investigate multiply charged molecular ions. The stabil ity of triply charged hydrocarbon ions depends strongly on the number of hy drogen atoms of the molecule. C4Hj3+ were observed only for molecules that contain more than 2 hydrogen atoms. Parallel, highly correlated ab initio c alculations were performed for these molecular ions. The binding energies o btained by these computations agree well with the experimental findings. Mo reover, there is quantitative agreement between the experiment and the calc ulations on the kinetic energy of the fragment ions upon Coulomb explosion. (C) 2001 American Institute of Physics.