title: Photoionisation study of Xe.CF4 and Kr.CF4 van-der-Waals molecules.
abstract: We report on photoionization studies of Xe.CF4 and Kr.CF4 van-der-Waals complexes produced in a supersonic expansion and detected using synchrotron radiation and photoelectron-photoion coincidence techniques. The ionization potential of CF4 is larger than those of the Xe and Kr atoms and the ground state of the Rg.CF4 (+) ion correlates with Rg(+) ((2)P3/2) + CF4. The onset of the Rg.CF4 (+) signals was found to be only ∼0.2 eV below the Rg ionization potential. In agreement with experiment, complementary ab initio calculations show that vertical transitions originating from the potential minimum of the ground state of Rg.CF4 terminate at a part of the potential energy surfaces of Rg.CF4 (+), which are approximately 0.05 eV below the Rg(+) ((2)P3/2) + CF4 dissociation limit. In contrast to the neutral complexes, which are most stable in the face geometry, for the Rg.CF4 (+) ions, the calculations show that the minimum of the potential energy surface is in the vertex geometry. Experiments which have been performed only with Xe.CF4 revealed no Xe.CF4 (+) signal above the first ionization threshold of Xe, suggesting that the Rg.CF4 (+) ions are not stable above the first dissociation limit.
authors.affiliation: St. Petersburg State University, 7/9 Universitetskaya Nab., St. Petersburg 199034, Russia.
authors.forename: V A
authors.initials: VA
authors.lastname: Alekseev
authors.affiliation: Synchrotron Soleil, Orme des Merisiers, St. Aubin BP 48, 91192 Gif sur Yvette Cedex, France.
authors.forename: G A
authors.initials: GA
authors.lastname: Garcia
authors.affiliation: St. Petersburg State University, 7/9 Universitetskaya Nab., St. Petersburg 199034, Russia.
authors.forename: R
authors.initials: R
authors.lastname: Kevorkyants
authors.affiliation: Synchrotron Soleil, Orme des Merisiers, St. Aubin BP 48, 91192 Gif sur Yvette Cedex, France.
authors.forename: L
authors.initials: L
authors.lastname: Nahon