Oxides and Oxohalides of Xe Three oxides of xenon are known: xenon trioxide (XeO3) and xenon tetroxide (XeO4) both of which are dangerously explosive and powerful oxidizing agents, and xenon dioxide (XeO 2 ), which was reported in 2011 with a coordination number of four. XeO 2 forms when xenon tetrafluoride is poured over ice. Xenon does not react with oxygen directly; the trioxide is formed by the hydrolysis of XeF6. XeO3 is weakly acidic, dissolving in alkali to form unstable xenate salts containing the HXeO − 4 anion. These unstable salts easily disproportionate into xenon gas and perxenate salts, containing the XeO6 4− anion. Barium perxenate, when treated with concentrated sulfuric acid , yields gaseous xenon tetroxide
A number of xenon oxyfluorides are known, including XeOF 2 , XeOF 4 , XeO 2 F 2 , and XeO 3 F 2 . XeOF 2 is formed by reacting OF 2 with xenon gas at low temperatures. It may also be obtained by partial hydrolysis of XeF 4 . It disproportionates at −20 °C into XeF 2 and XeO 2 F 2 .XeOF 4 is formed by the partial hydrolysis of XeF 6 .