Reactions with xenon fluorides

REACTIONS OF THE OXIDES OF NITROGEN 5.8 REACTIONS WITH XENON FLUORIDES 

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Reaction with KrF2 6, 3.9.4 Reaction with xenon fluorides and oxyfluorides 6, 3.9.3 Reaction with NSF 5, 3.3.4.1 BFe... 

Many of the reactions that xenon fluorides undergo are similar in some ways to those of interhalogens. However, the xenon halides differ markedly in terms of their reactivity, with XF2 being much less reactive than either XeF4 or XeF6. The difluoride reacts only slowly with water,... 

Xenon also forms many fluoroanions and their salts, mostly prepared from xenon tetrafluoride and hexafluoride. Such compounds include Na+XeFs and Cs" XeF7- formed by reactions of xenon fluorides with sodium fluoride or cesium fluoride. The dicesium xenon octafluoride, Cs2XeFs, is a stable yellow solid that decomposes above 400°C. 

Raman studies, 23 287, 294 residue compounds, 23 283, 314-315 staging, 23 282-283 with xenon fluorides, 23 296-300 comparative survey of, 1 263-264 mode of reaction of, 1 224-226 oxide, homopolar bonding and, 1 226-230 polar bonding... 

Reactions of Organic Compounds with Xenon Fluorides ... 

Reactions of Organic Compounds with Xenon Fluorides Filler, R hr J Chem 17, 71-79 56... 

Xenon reacts directly with fluorine to form fluorides. Other compounds of Xe can be prepared by reactions using xenon fluorides as starting materials, which fall into four main types ... 

C. Reactions of Xenon Fluorides with Aromatic Molecules. 842... 

Xenon difluoride reacts also with some halosubstituted alkanes18,19 at room temperature in chloroform, carbon tetrachloride, dichloromethane or bromoform, and depending on the nature of the solvent used chloro or bromo derivatives are isolated with imidazo-(l,2-fr)-pyridazine18. Carbon tetrachloride reacts with xenon difluoride at 180°C, while room-temperature transformations are achieved when various catalysts [antimony trifluoride, tantalum(V) fluoride or silica dioxide] are used, whose structure also influences the product distribution20. Tris(fluorosulfonyl)methane gives a fluoro-substi-tuted product in its reaction with xenon difluoride in difluorodichloromethane21. 

Of course, most reactive metal fluorides, such as cobalt trifluoride [268] and vanadium pentafluoride, will react with alkenes but the reactions can be very difficult to control, except for haloalkenes [269]. Much easier control is possible with xenon fluorides [137], the reactivity decreasing in the series XeFe > Xep4 > Xep2. Since the first report of the use of xenon difluoride for the addition of fluorine to double bonds, many studies have been published and reviewed [54, 135] (Figure 3.61). 

Oxidative fluorination of alkyl- or aryl-phosphines R PH3 for R = Ph, C6Hu, or NCCH2CH2 occurred on reaction with xenon difluoride, but with the chlorides Ph PCl3 there was also chlorine substitution, and the products were the normal phenyl fluorophosphoranes. In the presence of PhPp4, phosphorus trifluoride can be inserted into the C—F bond of 1-adamantyl fluoride to produce the previously inaccessible l-adamantyltetrafluorophosphorane ° substitution of PF3 by Bu Pp2 or 1-adamantyldifluorophosphine led to, respectively, 1-adamantyl-t-butyl-trifluorophosphorane and bis( 1 -adamantyl)trifluorophosphorane. 

Krypton difluoride cannot be synthesized by the standard high pressure-high temperature means used to prepare xenon fluorides because of the low thermal stabitity of KrF. There are three low temperature methods which have proven practical for the preparation of gram and greater amounts of KrF (141—143). Radon fluoride is most conveniently prepared by reaction of radon gas with a tiquid halogen fluoride (CIE, CIE, CIE, BrE, or lE ) at room temperature (144,145). 

Although uncontrolled reaction of xenon hexafluoride and moisture produces explosive xenon trioxide, controlled action by progressive addition of limited amounts of water vapour with agitation to a frozen solution of the hexafluoride in anhydrous hydrogen fluoride at —196° C to give xenon oxide tetrafluoride or xenon dioxide difluoride is safe [1], Controlled hydrolysis in solution in hydrogen fluoride is, however, described as hazardous [2],... 

In the reaction of the pentaoxide with xenon tetrafluoride oxide to give xenon difluoride dioxide and nitryl fluoride, the xenon tetrafluoride oxide must be used in excess to avoid formation of xenon trioxide, which forms a sensitive explosive mixture with xenon difluoride dioxide. 

Heats of formation for a complete set of Group VILA fluorides are unavailable, but a set of xenon fluoride cations, isoelectronic with iodine fluorides, exhibits the alternating pattern expected for odd- and even-electron molecules. The original energy-level diagram for stepwise fluorine dissociation is shown in Fig. 5. The tabulated values were derived from the ionization energies of XeF and the threshold values for XeFJ — XeF, - + F, where n is even (27), together with heats of formation obtained by reaction calorimetry (137). 

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