Silver(III) fluoride
{{Short description|Unstable silver compound in the unusual +3 oxidation state}}
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| ImageFile = Crystal_structure_of_AuF3.png
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| IUPACName = Silver(III) fluoride
| OtherNames = Silver trifluoride
Argentic fluoride
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| Section1 = {{Chembox Identifiers
| CASNo = 91899-63-7
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| ChEBI = 30338
| ChemSpiderID = 65322083
| Gmelin = 100808
| PubChem = 139031062
| SMILES = [F-].[F-].[F-].[Ag+3]
| InChI=1S/Ag.3FH/h;3*1H/q+3;;;/p-3
| InChIKey = PGGQSYHSNJQLOQ-UHFFFAOYSA-K
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| Section2 = {{Chembox Properties
| Formula = AgF3
| MolarMass = 164.86 g/mol
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| Section3 = {{Chembox Hazards
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Silver(III) fluoride, AgF3, is an unstable, bright-red, diamagnetic compound containing silver in the unusual +3 oxidation state. Its crystal structure is very similar to that of gold(III) fluoride: it is a polymer consisting of rectangular AgF4 units linked into chains by fluoro bridges.{{cite journal | title=Silver Trifluoride: Preparation, Crystal Structure, Some Properties, and Comparison with AuF3 | journal=J Am Chem Soc |year=1991 | volume=113 | pages=4192–4198 | doi=10.1021/ja00011a021| last1=Zemva | first1=Boris | last2=Lutar | first2=Karel | last3=Jesih | first3=Adolf | last4=Casteel | first4=William J. | last5=Wilkinson | first5=Angus P. | last6=Cox | first6=David E. | last7=von Dreele | first7=Robert B. | last8=Borrmann | first8=Horst | last9=Bartlett | first9=Neil | issue=11 }}
Preparation
AgF3 can be prepared by treating a solution containing tetrafluoroargentate(III) ions in anhydrous hydrogen fluoride with boron trifluoride;{{cite thesis | type=PhD |last=Casteel |first=William |date=September 1992 |title= The Synthesis and Structural Characterization of Novel Transition Metal Fluorides |url=https://www.osti.gov/servlets/purl/7017272}} the potassium tetrafluoroargentate(III) was prepared by heating a stoichiometric mix of potassium and silver nitrate in a sealed container filled with pressurised fluorine gas at 400C for 24 hours, twice. When dissolved in anhydrous HF, it decomposes spontaneously to Ag3F8 overnight at room temperature. The high-valence silver compounds described in the thesis are notable for their variety of colours: KAgF4 is bright orange, AgF3 bright red, AgFAsF6 is deep blue, Ag3F8 deep red-brown, and Pd(AgF4)2 is lime-green.
Earlier preparations used krypton difluoride as fluorinating agent, and tended to produce the mixed-valence Ag3F8 which may be thought of as silver(II) tetrafluoroargentate(III); Ag2F5, which is (AgF)+AgF4−, is formed by reacting AgF3 with AgFAsF6.
References
{{Silver compounds}}
{{Fluorides}}