yield by a factor of 3 when the photon energy is above the ionization threshold of C${}_{\mathrm{F}}$. As the yield of the {H${}^{+}$, CF${}_{2}^{+}$, Cl${}^{+}$, Br${}^{+}$} does not show a clear tendency, the numbers shown do not provide a watertight indication of selective excitation. In addition, an increase is expected above the photoionization threshold of the stereocenter (i.e. at 299 eV in our experiment), as the hydrogen is bound to C${}^{\star}$.\
We therefore chose to additionally investigate the selective excitation for fragmentation into two cations where clear features in the electron spectra can be seen. Three break-ups could be identified that are ’complete’, i.e. where the sum of fragment masses corresponds to the parent ion’s mass: {Br${}^{+}$, CHClCF${}_{3}^{+}$} (**I**), {Cl${}^{+}$, CHBrCF${}_{3}^{+}$} (**II**), and {CF${}_{3}^{+}$, CHClBr${}^{+}$} (**III**).\
The electron spectra differ significantly for the three break-ups, indicating that they are induced by different electron dynamics. Figure \[fig:halothan\_2p\_electron\] shows the energy spectra for different photon energies (rows) and fragmentation pathways (columns).

Pathway **I**: When a bromine ion is split from the molecule, the corresponding electron spectrum shows a peak at around 45 eV. As this peak does not shift with the excitation energy, it is attributed to an Auger decay. The peak 