Gold-xenon compounds

Before leaving the NgMX complexes and the compound HArF introduced in Section 5.8.1, it is noted that a fuller discussion on the chemistry of noble gases may be found in Section 17.5, including a subsection on gold-xenon complexes in Section 17.5.6. 

A variety of new xenon compounds have been synthesized and characterized by Xe NMR as well as by NMR of the ligand species. The Seppelt group has reported a number of new compounds, including several xenon-gold compounds. 

As mentioned, krypton difluoride is an exceedingly powerful oxidizing and fluorinating agent, far more potent than Xep2. Thus, it oxidizes xenon to XeF and gold to the unique Au(V) compound KrF+AuFg" ... 

Only a few elements occur free in nature. The noble gases—helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn)—occur in air as separate atoms. In addition to occurring in compounds, oxygen (O), nitrogen (N), and sulfur (S) occur in their most common elemental form as the molecules O2, N2, and Sg, and carbon (C) occurs in vast, nearly pure deposits of coal. And some metals—copper (Cu), silver (Ag), gold (Au), and platinum (Pt)—are also sometimes found uncombined. But, aside from these few exceptions, the overwhelming majority of elements occur in compounds, combined with other elements. 

Another monomeric Au(II) compound, [Au"Xe4](Sb2Fjj)2, was produced by treatment of AuFj with xenon in SbFj/HF solution [44], The cation, [Au"Xe4] +, has a planar structure with Au-Xe distances ranging from 2.7279(6) to 2.7498(5) A. The remarkable ability of gold to bind xenon was first discovered with the preparation of [Au"Xe4](Sb2Fn)2. 

---