Fragmentation energetics and dynamics of fluorobenzene⋅Arn (n=1–3) clusters studied by mass analyzed threshold ionization spectroscopy

The dissociation of ${\mathrm{fluorobenzene\cdot Ar}}_n$ $\text{(n=1–3)}$ complexes was investigated using mass analyzed threshold ionization spectroscopy. All ion state spectra of the cationic complexes exhibit low-frequency vibrational progressions of van der Waals bending modes, which indicate a significant structural change of the complexes upon ionization. Upper limits for the dissociation thresholds in the cationic state could be determined for all complexes. In the case of ${\mathrm{fluorobenzene\cdot Ar}}_{\mathrm{2}}$ and ${\mathrm{fluorobenzene\cdot Ar}}_{\mathrm{3}},$ two fragmentation thresholds could be observed.