Bonding of Rare-Gas Atoms to Si in Reactions of Rare Gases with SiF₃⁺

Abstract

Direct bonding has been observed to occur between SiF3 + and the rare gases xenon, krypton, and argon in the gas phase at low collision energies and, in the case of xenon and krypton, 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) tandem 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, F3SiXe+, 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 SiF3 + or a F−Xe−F linkage formed by bond redisposition. The carbon analogue CF3 + did not form adduct ions with Xe under the same experimental conditions. Analogous experimental and theoretical studies are reported for the reactions of SiF3 + with Kr and Ar. Experimental results also are reported for the reaction of SiF3 + with N2 and O2.

Energetics of hydride and electron pair attachment to EX30/+ (E=B, C, Al, Si and X=F, Cl, Br, I) and the study of bonding trends among EX30/+, EX32−/−, and EX3H−/0 by use of ELF and NBO analyses

“…Although no FIA values are available for the SiX 3 + series, binding energies calculated for F 3 Si + -L (L = NH 3 , OH 2 , NCH) at the B3LYP/6-311G(2d,p) level indicate that SiF 3 + is a much stronger Lewis acid than CF 3 + [11]. It has been shown by tandem mass spectrometry [46] and by the gas-phase reaction of SiF 3 + with Ng (Ng = Ar, Kr, Xe) in a selected ion flow tube (SIFT) apparatus [47] that SiF 3 + forms the series of F 3 SiNg + cations. Similar attempts to form the F 3 CXe + cation in the gas phase were unsuccessful [47].…”

On the position of helium and neon in the Periodic Table of Elements

“…Obviously, analogous cationic species containing neon or argon are even more facile to manufacture than those of helium, since Lewis basicity (measured by proton affinity) of light noble gas atoms increases in the order: He (1.84 eV) \ Ne (2.06 eV) ( Ar (3.83 eV). Consequently, there is a vast literature on theoretical predictions of novel light noble gas-containing cations (Borocci et al 2010;Rzepa 2010;Pan et al 2016; these efforts were reviewed: Lewars 2008) and experimental reports, as well (Cunje et al 2001;Roithová and Schröder 2009;Lockyear et al 2010), to mention just a few examples. However, the neutral (solid state) analogues of helides (stabilized by counteranions) do not exist albeit their first xenon analogues were successfully prepared (Seppelt and Seidel 2000;Hwang et al 2003).…”

Cationic germanium fluorides

“…Compared with SiF + , the reaction between GeF + and H 2 O is apparently more efficient. From a general point of view, this suggests that the GeF n + cations (n = 1-3) could undergo ion-molecule reactions similar to the rich and variegated processes already ascertained for the cationic silicon fluorides [34][35][36][39][40][41][42][43][44][45][46]. This suggests novel opportunities in the positive ion chemistry of germanium.…”

“…Similar to SiF n + (n = 1-3) [34][35][36] and to other fluorinated cations such as NF 2 + [37] and PF 2 + [38], GeF + activates the robust H 2 O according to a reaction path strictly analogue to that involved in the reaction between SiF + and H 2 O [36]. From a general point of view, the conceivable occurrence of additional similarities between the reactivity of GeF n + and the rich and variegated chemistry of SiF n + [34][35][36][39][40][41][42][43][44][45][46] suggests novel attractive opportunities in the gas-phase positive ion chemistry of germanium.…”