Barium perxenate

Oxides. Two oxides of xenon are known xenon trioxide [13776-58-4], XeO, and xenon tetroxide [12340-14-6], XeO (Table 1). Xenon trioxide is most efftcientiy prepared by the hydrolysis of XeE (47) or by the reaction of XeE with HOPOE2 (48). The XeO molecule has a trigonal pyramidal shape Xe—O, 176(3) pm (49), and XeO is tetrahedral with Xe—O, 173.6(2) pm (50). Xenon tetroxide is prepared by the interaction of concentrated sulfuric acid with sodium or barium perxenate, Na XeO, Ba2XeO ( )- Both oxides are thermodynamically unstable, explosive soHds which must be... 

Xenon tetroxide is a highly unstable and explosive gas formed by the action of concentrated H2S04 on barium perxenate. It is tetrahedral (Xe—O = 1.736 A), according to electron diffraction studies. 

Barium perxenate reacts with sulfuric acid to yield unstable perxenic acid, which mostly dehydrates to xenon tetroxide, as shown below ... 

It is prepared from barium perxenate or sodium perxenate by reaction with anhydrous sulphuric acid. 

XeO is an unstable gas, exploding even at a low temperature. It is prepared by reaction of anhydrous HjSO with barium perxenate or sodium perxenate. 

With cold concentrated sulfuric acid, barium perxenate forms the insoluble barium sulfate, BaS04, and gaseous xenon tetroxide, Xe04 ... 

The perxenates are colorless, thermally stable solids. Anhydrous sodium perxenate can be obtained at 373 K. It decomposes at 633 K. The corresponding barium salt decomposes at about 570 K. Perxenate solutions are powerful and rapid oxidizing agents. Xenon(VIII) is reduced to xenon(VI). Oxidation processes in acid media are more effective, but they must be fast enough to compete with decomposition of the perxenate, which is also rapid in acid. 

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