Platinum hexafluoride
{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 476995092
| ImageFile = PtF6.png
| ImageClass = skin-invert-image
| ImageSize = 180px
| ImageFile2=Platinum-hexafluoride-3D-vdW.png
| ImageClass2 = bg-transparent
| IUPACName = Platinum(VI) fluoride
| OtherNames = Platinum hexafluoride
|Section1={{Chembox Identifiers
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/6FH.Pt/h6*1H;/q;;;;;;+2/p-6
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = NHVLQWBIZQMDAU-UHFFFAOYSA-H
| SMILES = F[Pt](F)(F)(F)(F)F
| InChI = 1S/6FH.Pt/h6*1H;/q;;;;;;+2/p-6
| InChIKey1 = NHVLQWBIZQMDAU-UHFFFAOYSA-H
| CASNo_Ref = {{cascite|changed|??}}
| CASNo = 13693-05-5
| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
| ChemSpiderID = 2283064
| EINECS = 237-214-0
| PubChem = 22238670
}}
|Section2={{Chembox Properties
| Formula = PtF6
| MolarMass = 309.07 g/mol
| Appearance = dark-red crystals
| Density = 3.83 g/cm3
| MeltingPtC = 61.3
| BoilingPtC = 69.14
| Solubility = Reacts with water
}}
|Section3={{Chembox Structure
| CrystalStruct = Orthorhombic, oP28
| SpaceGroup = Pnma, No. 62
| Coordination = octahedral (Oh)
| Dipole = 0
}}
|Section7={{Chembox Hazards
| MainHazards = Strong oxidizer
| NFPA-H = 4
| NFPA-F = 0
| NFPA-R = 4
| NFPA-S = OX
| FlashPt =
| AutoignitionPt =
}}
|Section8={{Chembox Related
| OtherCompounds = Platinum(IV) fluoride
Platinum(V) fluoride
}}
}}
Platinum hexafluoride is the chemical compound with the formula PtF6, and is one of seventeen known binary hexafluorides. It is a dark-red volatile solid that forms a red gas. The compound is a unique example of platinum in the +6 oxidation state. With only four d-electrons, it is paramagnetic with a triplet ground state. PtF6 is a strong fluorinating agent and one of the strongest oxidants, capable of oxidising xenon and O2. PtF6 is octahedral in both the solid state and in the gaseous state. The Pt-F bond lengths are 185 picometers.
Synthesis
PtF6 was first prepared by reaction of fluorine with platinum metal.{{cite journal | last1 = Weinstock | first1 = B. | last2 = Claassen | first2 = H. H. | last3 = Malm | first3 = J. G. | year = 1957 | title = Platinum Hexafluoride | journal = Journal of the American Chemical Society | volume = 79 | issue = 21| pages = 5832 | doi = 10.1021/ja01578a073 }} This route remains the method of choice.{{cite journal | doi = 10.1021/ic052029f | title = Solid State Molecular Structures of Transition Metal Hexafluorides | date = 2006 | last1 = Drews | first1 = Thomas | last2 = Supeł | first2 = Joanna | last3 = Hagenbach | first3 = Adelheid | last4 = Seppelt | first4 = Konrad | journal = Inorganic Chemistry | volume = 45 | issue = 9 | pages = 3782–3788 | pmid = 16634614 }}
:Pt + 3 F2 → PtF6
PtF6 can also be prepared by disproportionation of the pentafluoride (PtF5), with the tetrafluoride (PtF4) as a byproduct. The required PtF5 can be obtained by fluorinating PtCl2:
:2 PtCl2 + 5 F2 → 2 PtF5 + 2 Cl2
:2 PtF5 → PtF6 + PtF4
Hexafluoroplatinates
Platinum hexafluoride can gain an electron to form the hexafluoroplatinate anion, {{chem|Pt|F|6|-}}. It is formed by reacting platinum hexafluoride with relatively uncationisable elements and compounds, for example with xenon to form "{{chem|Xe|Pt|F|6}}" (actually a mixture of {{chem|Xe|F|Pt|F|5}}, {{chem|Xe|F|Pt|2|F|11}}, and {{chem|Xe|2|F|3|Pt|F|6}}), known as xenon hexafluoroplatinate. The discovery of this reaction in 1962 proved that noble gases form chemical compounds. Previous to the experiment with xenon, {{chem|Pt|F|6}} had been shown to react with oxygen to form [O2]+[PtF6]−, dioxygenyl hexafluoroplatinate.
See also
References
{{reflist}}
General reading
- Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. {{ISBN|0-12-352651-5}}.
{{Platinum compounds}}
{{Hexafluorides}}
{{fluorine compounds}}