Spontaneous oxidation of xenon to Xe(II) by cationic Ag(II) in anhydrous hydrogen fluoride solutions

Real and Hypothetical Intermediate-Valence AgII/AgIII and AgII/AgI Fluoride Systems as Potential Superconductors

“…The formula Ag I Ag III [SbF 6 À ] 2 has been suggested [37] for the b form. Mixed-valence (and not intermediate-valence) character of the b form might be confirmed, for example, by the (24) and (42) local environments for the Ag I and Ag III centers, respectively. [52] Unfortunately, there is still no structural data for the b-AgSb 2 F 12 form.…”

“…[28] 4 ] À is shown in Figure 4. Usually the Ag II cation is found in these substances in a compressed octahedral (24) [e] In this structure (ªRbNiCrF 6 º-type) the Ag II and M III (Sc, In, Tl) centers are statistically distributed on the same position, so it is not possible (by powder data) to locate the Ag II center or describe its coordination (B. G. Müller). [60] These compounds crystallize in a hexagonal system and the local coordination of F atoms around the Ag centers is regular trigonal bipyramidal ( Figure 6).…”

The room temperature preparation of metastable fluorides and potent oxidizers

“…Similarly, it proved possible to make [24] true paramagnetic Au II salts by maintaining strongly acidic conditions during the fluorination of metallic gold in aHF. Oxidation of silver was also limited in acid (to Ag II ) but in accord with its high electronegativity this Ag II was shown to be a potent oxidizer, as its reduction by xenon [25] illustrated: 2Ag ðaHFÞ 2þ þ Xe ðaHFÞ þ 4AsF 6ðaHFÞ À ! 2Ag ðaHFÞ þ þ XeF ðaHFÞ þ þ 3AsF 6ðaHFÞ À þ AsF 5ðaHFÞ (9) This is consistent with the second ionization potential of silver (21.5 eV), which is the highest of any metal (other than alkali metals).…”

Elimination of AsF3 from anhydrous HF using AgFAsF6 as a mediator

“…The starting As content was adjusted to a few hundred or thousand ppm to reflect HF synthesized from As-containing fluorite such as that produced in Mexico. The oxidizing salt, AgFAsF 6 , was first reported in 1982 [4], and was characterized by several methods [5][6][7]. The solid-state structure of AgFAsF 6 contains a cationic (Ag-F) n chain, and an octahedral AsF 6 group cross-linked to the chain via F bridges [5].…”

“…The solid-state structure of AgFAsF 6 contains a cationic (Ag-F) n chain, and an octahedral AsF 6 group cross-linked to the chain via F bridges [5]. On the other hand, AgFAsF 6 dissociates into AgF + and AsF 6 À in anhydrous HF, resulting in lower oxidizing power than the naked Ag 2+ cation [7][8][9][10]. Following the oxidation of As(III) to As(V), AgFAsF 6 can be easily regenerated using F 2 gas at room temperature.…”