Xenates

Xenates and Perxenates. Alkali metal xenates of composition MHXe04-1.5H20, where M is sodium, potassium, mbidium, or cesium, have been prepared by free2e-dryiQg mixtures of xenon trioxide and the corresponding metal hydroxides ia 1 1 molar ratios. The xenates are unstable, explosive solids. 

For convenience, the even rarer and less stable krypton compounds are also covered in this entry. All xenon compounds are very strong oxidants and many are also explosively unstable. For a now obsolete review, see [1]. A recent compact review of noble gas chemistry is found in [2], A series of alkali xenates, MH0Xe03.1.5H20 are unstable explosive solids. The equivalent fluoroxenates MFXe03are far more stable. Individually indexed compounds are ... 

Caesium bromoxenate, 0237 Caesium chloroxenate, 3970 Caesium hydrogen xenate, 4259... 

As mentioned above, xenon trioxide is an endothermic compound which explodes violently at the slightest provocation. Aqueous solutions are stable but powerfully oxidizing. These solutions are weakly acidic ( xenic acid ) and contain molecular XeOj When these solutions are made basic. HXeO ions are formed and alkali hydrogen xenates, MHXe04, may be isolated from them. Hydrogen xenale ions disproportionate in alkaline solution to yield perxenates ... 

Xenate solutions may also be oxidized directly to perxenate with ozone. Solid perxenates are rather insoluble and are unusually stable for xenon-oxygen compounds Most do not decompose until healed above 200 eC. X-ray crystallographic structures have been determined for several perxenates. and they have been found to contain the octahedral XeC ion. which persists in aqueous solution (possibly with proionation to HXeOj"). 

Caesium dodeca(trifluoromethyl)carbadodecaborane(14)[l-], see Caesium dodecakistrifluoromethylcarba-cfoso-dodecaborate, 3589b Caesium fluoride, 4249 Caesium fluoroxysulfate, 4250 Caesium graphite, 2877 Caesium hexafluorobromate, 0236 Caesium hexahydroaluminate(3—), 0067 Caesium hydride, 4252 Caesium hydrogen xenate, 4253 Caesium lithium tridecahydrononaborate, 0194 Caesium nitrate, 4255 Caesium nitride, 4260 Caesium oxide, 4258... 

Potassium hydrogen diazirine-3,3-dicarboxylate, 1065 Potassium hydrogen peroxomonosulfate, 4424 Potassium hydrogen tartrate, 1458 Potassium hydrogen xenate, 4423 Potassium hydroxide, 4422... 

Caesium bromoxenate, 0237 Caesium chloroxenate, 3964 Caesium hydrogen xenate, 4253 Krypton difluoride, 4307 Potassium hexaoxoxenonate—xenon trioxide, 4669 Tetrafluoroammonium hexafluoroxenate, 4380 Xenon difluoride, 4326 Xenon difluoride dioxide, 4316 Xenon difluoride oxide, 4313 Xenon hexafluoride, 4371 Xenon tetrafluoride, 4347 Xenon tetrafluoride oxide, 4340 Xenon tetraoxide, 4857... 

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