A stable argon compound

Abstract

The noble gases have a particularly stable electronic configuration, comprising fully filled s and p valence orbitals. This makes these elements relatively non-reactive, and they exist at room temperature as monatomic gases. Pauling predicted in 1933 that the heavier noble gases, whose valence electrons are screened by core electrons and thus less strongly bound, could form stable molecules. This prediction was verified in 1962 by the preparation of xenon hexafluoroplatinate, XePtF6, the first compound to contain a noble-gas atom. Since then, a range of different compounds containing radon, xenon and krypton have been theoretically anticipated and prepared. Although the lighter noble gases neon, helium and argon are also expected to be reactive under suitable conditions, they remain the last three long-lived elements of the periodic table for which no stable compound is known. Here we report that the photolysis of hydrogen fluoride in a solid argon matrix leads to the formation of argon fluorohydride (HArF), which we have identified by probing the shift in the position of vibrational bands on isotopic substitution using infrared spectroscopy. Extensive ab initio calculations indicate that HArF is intrinsically stable, owing to significant ionic and covalent contributions to its bonding, thus confirming computational predictions that argon should form a stable hydride species with properties similar to those of the analogous xenon and krypton compounds reported before.

Chemical reactions in the xenon-acetylene systems irradiated with fast electrons at 16 K: formation of xenon-containing molecules and radicals

“…Be cause of this, signals of the HXeCC • radicals can be de tected only if they are not superimposed with lines of other radicals (see above). For the same reason reac tion (7) in our experiments plays an insignificant role even at maximum irradiation dose and the band assigned to HXeCCXeH molecules 10,12 is of very low intensity. Much higher relative concentrations of HXeCC • radicals can probably be obtained using post radiation UV pho tolysis in the absorption band of ethynyl radical followed by annealing.…”

Are matrix isolated species really “isolated”? Infrared spectroscopic and theoretical studies of noble gas-transition metal oxide complexes

“…Since the report [7,8] of the first stable xenon-containing compound, XePtF 6 , a large number of chemically bound complexes containing heavier noble gas atoms have been prepared [9,10]. Recent investigations have shown that even a light noble gas, argon, is able to form the chemically bound compound HArF in solid argon [11]. It has also been found that noble gas atoms are able to coordinate to metal centers and form noble gas-metal complexes.…”

Ground-State Reversal by Matrix Interaction: Electronic States and Vibrational Frequencies of CUO in Solid Argon and Neon

“…We are examining these interactions carefully, especially in light of the recent report of the new stable argon molecule HArF. [13] The potential energy surfaces (PES) along the bending coordinate are quite complicated for both the 1 S ground state and the 3 F excited state of linear CUO. Although CUO is isoelectronic to UO 2 2 , the UÀO and UÀC interactions are much more localized in CUO than are the symmetryequivalent U À O interactions in UO 2 2 .…”