The Vibrational Population Distribution of H_2+. Formed from a Series of Different Precursor Molecules

The collision induced spectra of H_2^+\cdot -> H^+ have been measured by translational spectroscopy, where the hydrogen molecular ion was formed from a series of hydrogen-containing precursors. Differences in the shapes of the collision-induced spectra were observed, which reflect upon the initial vibrational distributions in which H_2^+\cdot was formed. These distributions were calculated, for each precursor, by associating to each vibrational level an individual kinetic energy release distribution, from which the experimentally observed spectra were regenerated by a computer simulation. Each calculated distribution was normalized to a previously published vibronic distribution obtained from a photo-dissociation study of H_2^+\cdot. The vibrational population distributions of H_2^+\cdot product ions, for each precursor, show small deviations, for ν <=slant 12, from that obtained when hydrogen gas was the precursor, and differences of between a factor 0.8 to 3 for higher vibrational levels.