Mass analyzed threshold ionization of chlorobenzene and chlorobenzene · Ar1

Mass analyzed threshold ionization (MATI) spectra of the 35Cl and 37Cl isotopomers of chlorobenzene have been recorded via different vibrational S1 states. Most cationic states exhibit only a small isotopic shift of 2–4 cm−1. The strongest isotope effect is observed for the 6a vibrational mode, which differs by about 6 cm−1 for the two isotopomers. MATI spectra have also been recorded for the Van der Wals complex chlorobenzene · Ar1. Upper limits for the dissociation energies of the complex in its cationic state, as well as in its neutral states S0 and S1 could be determined.