Pulsed field threshold ionization of van der Waals complexes. The dissociation energy of ionic and neutral dibenzo-p-dioxin·Ar and ·84Kr

The technique of mass selective pulsed field threshold ionization of high long-lived Rydberg states has been applied to dibenzo-p-dioxin (DD), DD·Ar, and DD·84Kr yielding adiabatic ionization energies of 61283, 61071, and 61005 cm−1, respectively. A sharp energetic threshold for the disappearance of the parent threshold ion signal of (DD·Ar)+ and the appearance of the daughter threshold ion signal is observed. This leads to accurate values of the dissociation energy E0 = 717 cm−1 in (DD·Ar)+, E0 = 918 cm−1 in (DD·84Kr)+ and to D0 = 505 cm−1 in DD·Ar, D0 = 640 cm−1 in DD·84Kr.