Editing Xenon (section)

=== Halides ===
[[File:Xenon-tetrafluoride-3D-vdW.png|thumb|[[Xenon tetrafluoride]] | alt=A model of planar chemical molecule with a blue center atom (Xe) symmetrically bonded to four peripheral atoms (fluorine).]]
[[File:Xenon tetrafluoride.png|thumb|XeF<sub>4</sub> crystals, 1962|alt=Many cubic transparent crystals in a petri dish.]]

Three [[fluoride]]s are known: [[xenon difluoride|{{chem|XeF|2}}]], [[xenon tetrafluoride|{{chem|XeF|4}}]], and [[xenon hexafluoride|{{chem|XeF|6}}]]. XeF is theorized to be unstable.<ref>{{Cite journal
| title   = Probable nonexistence of xenon monofluoride as a chemically bound species in the gas phase
| author  = Dean H Liskow
| author2 = Henry F Schaefer III
| author3 = Paul S Bagus
| author4 = Bowen Liu
| journal = J Am Chem Soc
| year    = 1973
| volume  = 95
| issue   = 12
| pages   = 4056–57
| doi     = 10.1021/ja00793a042
| bibcode = 1973JAChS..95.4056L
}}</ref> These are the starting points for the synthesis of almost all xenon compounds.

The solid, crystalline difluoride {{chem|XeF|2}} is formed when a mixture of [[fluorine]] and xenon gases is exposed to ultraviolet light.<ref>{{cite journal
| last    = Weeks
| first   = James L.
| author2 = Chernick, Cedric
| author3 = Matheson, Max S.
| title   = Photochemical Preparation of Xenon Difluoride
| journal = Journal of the American Chemical Society
| volume  = 84
| issue   = 23
| pages   = 4612–13
| doi     = 10.1021/ja00882a063
| year    = 1962
| bibcode = 1962JAChS..84.4612W
}}</ref> The ultraviolet component of ordinary daylight is sufficient.<ref>{{cite journal
| author  = Streng, L. V.
| author2 = Streng, A. G.
| title   = Formation of Xenon Difluoride from Xenon and Oxygen Difluoride or Fluorine in Pyrex Glass at Room Temperature
| journal = Inorganic Chemistry
| year    = 1965
| volume  = 4
| issue   = 9
| pages   = 1370–71
| doi     = 10.1021/ic50031a035
}}</ref> Long-term heating of {{chem|XeF|2}} at high temperatures under an {{chem|NiF|2}} catalyst yields {{chem|XeF|6}}.<ref name="tramsek">{{cite journal
| author  = Tramšek, Melita
| author2 = Žemva, Boris
| title   = Synthesis, Properties and Chemistry of Xenon(II) Fluoride
| journal = Acta Chimica Slovenica
| date    = December 5, 2006
| volume  = 53
| issue   = 2
| pages   = 105–16
| doi     = 10.1002/chin.200721209
}}</ref> Pyrolysis of {{chem|XeF|6}} in the presence of [[sodium fluoride|NaF]] yields high-purity {{chem|XeF|4}}.<ref>{{cite journal
| author  = Ogrin, Tomaz
| author2 = Bohinc, Matej
| author3 = Silvnik, Joze
| title   = Melting-point determinations of xenon difluoride-xenon tetrafluoride mixtures
| journal = [[Journal of Chemical and Engineering Data]]
| year    = 1973
| volume  = 18
| issue   = 4
| page    = 402
| doi     = 10.1021/je60059a014
}}</ref>

The xenon fluorides behave as both fluoride acceptors and fluoride donors, forming salts that contain such cations as {{chem |XeF|+}} and {{chem |Xe}}{{su |b= 2}}{{chem |F|3|+}}, and anions such as {{chem |XeF|5|-}}, {{chem |XeF|7|-}}, and {{chem |XeF|8|2-}}.  The green, paramagnetic {{chem |Xe|2|+}} is formed by the reduction of {{chem|XeF|2}} by xenon gas.<ref name="harding1">{{cite book
| author    = Harding, Charlie
| author2   = Johnson, David Arthur
| author3   = Janes, Rob
| title     = Elements of the ''p'' block
| pages     = 93–94
| publisher = Royal Society of Chemistry
| location  = Great Britain
| date      = 2002
| isbn      = 0-85404-690-9
| url       = https://books.google.com/books?id=W0HW8wgmQQsC&pg=PA93
}}</ref>

{{chem|XeF|2}} also forms [[complex (chemistry)|coordination complexes]] with transition metal ions. More than 30 such complexes have been synthesized and characterized.<ref name="tramsek" />

Whereas the xenon fluorides are well characterized, the other halides are not.  [[Xenon dichloride]], formed by the high-frequency irradiation of a mixture of xenon, fluorine, and [[silicon tetrachloride|silicon]] or [[carbon tetrachloride]],<ref name="scott1">{{cite encyclopedia
| title        = Xenon Compounds
| encyclopedia = Concise encyclopedia chemistry
| publisher    = [[Walter de Gruyter]]
| url          = https://books.google.com/books?id=Owuv-c9L_IMC&pg=PA1183
| year         = 1994
| page         = 1183
| isbn         = 3-11-011451-8
| author       = Scott, Thomas
| author2      = Eagleson, Mary
}}</ref> is reported to be an endothermic, colorless, crystalline compound that decomposes into the elements at 80&nbsp;°C. However, {{chem|XeCl|2}} may be merely a [[van der Waals molecule]] of weakly bound Xe atoms and {{chem |Cl|2}} molecules and not a real compound.<ref>{{cite journal
| author  = Proserpio, Davide M.
| author2 = Hoffmann, Roald
| author3 = Janda, Kenneth C.
| title   = The xenon-chlorine conundrum: van der Waals complex or linear molecule?
| year    = 1991
| volume  = 113
| journal = Journal of the American Chemical Society
| issue   = 19
| pages   = 7184–89
| doi     = 10.1021/ja00019a014
| bibcode = 1991JAChS.113.7184P
}}</ref> Theoretical calculations indicate that the linear molecule {{chem|XeCl|2}} is less stable than the van der Waals complex.<ref>{{cite journal
| author  = Richardson, Nancy A.
| author2 = Hall, Michael B.
| year    = 1993
| title   = The potential energy surface of xenon dichloride
| journal = The Journal of Physical Chemistry
| volume  = 97
| issue   = 42
| pages   = 10952–54
| doi     = 10.1021/j100144a009
}}</ref> [[Xenon tetrachloride]] and [[xenon dibromide]] are even more unstable and they cannot be synthesized by chemical reactions. They were created by [[radioactive decay]] of {{chem |129|ICl|4|-}} and {{chem |129|IBr|2|-}}, respectively.<ref name="book bell2013syntheses">{{cite book
| title     = Syntheses and Physical Studies of Inorganic Compounds
| author    = Bell, C.F.
| isbn      = 978-1-4832-8060-8
| year      = 2013
| page      = 143
| publisher = Elsevier Science
}}</ref><ref name="book cockett2013chemistry">{{Cite book
| title     = The Chemistry of the Monatomic Gases: Pergamon Texts in Inorganic Chemistry
| author1   = Cockett, A.H.
| author2   = Smith, K.C.
| author3   = Bartlett, N.
| isbn      = 978-1-4831-5736-8
| year      = 2013
| page      = 292
| publisher = Elsevier Science
}}</ref>