Xenon (VI) oxide

Structural formula
General
Surname	Xenon (VI) oxide
other names	Xenon trioxide
Molecular formula	XeO 3
Brief description	white, explosive crystals
External identifiers / databases
ChemSpider	21106493
Wikidata	Q411169
properties
Molar mass	179,30 g · mol -1
Physical state	firmly
density	4.55 g cm −3
Melting point	explosive decomposition: 25 ° C
solubility	easily soluble in water
safety instructions
GHS hazard labeling ; no classification available
GHS hazard labeling ; no classification available
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Xenon (VI) oxide ( empirical formula XeO ₃ ) is a chemical compound of the elements xenon and oxygen . Xenon trioxide is unstable and tends to decompose explosively at a temperature of around 25 ° C. It is one of the few known water-soluble noble gas compounds . The unstable xenonic acid (H ₂ XeO ₄ ) is produced to a small extent in a slightly basic medium .

presentation

Xenon trioxide cannot be represented directly because the electronegativity of the oxygen is not sufficient for the direct reaction. Therefore xenon difluoride is first produced by allowing xenon to react with fluorine under high pressure and high temperature . The xenon difluoride then reacts with disproportionation to xenon tetrafluoride and xenon, then to xenon hexafluoride and xenon difluoride. Finally, the fluorine in the compound is replaced by oxygen through conversion with lye and calcium salts, with intermediate products such as xenon tetrafluoride oxide and xenon difluoride dioxide being formed.

By reacting xenon (VI) fluoride with excess water and removing the resulting hydrogen fluoride , a relatively stable solution of xenon (IV) oxide is obtained as long as it remains slightly acidic:

{\ displaystyle {\ ce {XeF6 + 3 H2O -> XeO3 + 6 HF}}}

Typical reactions of xenon trioxide

In a strongly alkaline solution, a hydroxide ion (OH ^- ) is added, so that HXeO ₄^- is formed. This HXeO ₄^- gradually disproportionates to perxenate (Xe ^{+ VIII} ) and xenon (Xe ⁰ ). It can then Perxenate such. B. Isolate Na ₄ XeO ₆ · 6H ₂ O.
By adding conc. Sulfuric acid (H ₂ SO ₄ ), the gaseous, highly explosive anhydride xenon tetroxide (XeO ₄ ) can be obtained from the yellow perxenate solutions (e.g. from Ba ₂ XeO ₆ ) .

Xenate (+ VI), here in the form of XeO ₃ , and perxenate (+ VIII) are among the strongest oxidizing agents . (Standard electrode potentials : E ⁰ (Xe / XeO ₃ ) = +1.8 V; E ⁰ (Xe / XeO ₆⁴⁻ ) = +3.0 V). They are all the more interesting because in their reduction only elemental xenon is created that can be used again and again.

There are (or were in 1992) indications of the formation of xenate esters in the violent reaction of XeO ₃ with alcohols

When ozone (O ₃ ) is passed through a dilute XeO ₃ solution, perxenates (Xe ^{+ VIII} ) are formed, which can form stable sodium and barium salts

proof

Xenon (VI) oxide solutions can be examined quantitatively by adding iodine and dilute perchloric or sulfuric acid to quantitatively decompose the compound according to the following equation and titrating the triiodide ion contained in the solution with thiosulfate iodometrically .

{\ displaystyle {\ ce {XeO3 + 9 I- + 6 H + -> Xe + 3 I3- + 3 H2O}}}

Individual evidence

↑ Entry on xenon connections. In: Römpp Online . Georg Thieme Verlag, accessed on July 14, 2014.
↑ ^a ^b webelements.com: Xenon trioxide
^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 .
↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
^ ^A ^b ^c Evan H. Appelman: Xenon trioxide solution . In: William L. Jolly (Ed.): Inorganic Syntheses . tape 11 . McGraw-Hill Book Company, Inc., 1968, p. 205-210 (English).

literature

Christen / Meyer: General and Inorganic Chemistry Vol. II. Frankfurt am Main, 1995
Hans Rudolf Christen: Basics of General and Inorganic Chemistry. Frankfurt am Main, 1968
Shriver / Atkins / Langford: Inorganic Chemistry. Weinheim, New York, Basel, Cambridge, 1992
Cotton / Wilkinson: Inorganic Chemistry. Weinheim, 1974

[1] Entry on xenon connections. In: Römpp Online . Georg Thieme Verlag, accessed on July 14, 2014.

[webelements-2] webelements.com: Xenon trioxide

[HoWi-3] AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 .

[NV-4] This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.

[IS11-5] A ^b ^c Evan H. Appelman: Xenon trioxide solution . In: William L. Jolly (Ed.): Inorganic Syntheses . tape 11 . McGraw-Hill Book Company, Inc., 1968, p. 205-210 (English).