Bonding of Rare-Gas Atoms to Si in Reactions of Rare Gases with SiF_3~+

摘要

Direct bonding has been observed to occur between SiF_3~+ and the rare gases xenon, krypton, and agron in the gas phase at low collision energies and , in the case of xenon and krupton, also at high collision energies. The kinetics of low-energy addition have been monitored at room temperature in He buffer gas at 0.35 Torr using the selected-ion flow tube(SIFT)tanem mass-spectrometer technique . An investigation of the energetics of dissociation of the adduct ions in multi-collision induced dissociation experiments revealed the formation of adduct ions at high collision energies.Experimental and theoretical results are presented for the formation and stability of two possible low-energy isomers of the gaseous trifluorosilylxenon cation, F_3SiXe~+ , one formed by the direct bonding of Xe to Si and the other by Xe being attached to one F atom. Two possible high-energy isomers are proposed that contain a Si-Xe-F linkage formed by the insertion of Xe into SiF_3~+ or a F-Xe-F linkage formed by bond redisposition. The carbon CF_3~+ did not form adduct ions with Xe under the same experimental conditiosn. Analogous experimental and theoreticla studies are reported for the reactions of SiF_3~+ with Kr and Ar. Experimental results also are reported for the reaction of SiF_3~+ with N_2 and O_2