Teflic acid#Teflates
{{Chembox
| Watchedfields = changed
| verifiedrevid = 470481620
| ImageFileL1 = Teflic_acid_2D_full.svg
| ImageSizeL1 = 120
| ImageAltL1 = Structural formula
| ImageFileR1 = Teflic-acid-3D-spacefill.png
| ImageSizeR1 = 120
| ImageNameR1 = Space-filling model
| IUPACName = Pentafluoroorthotelluric acid
| OtherNames = Teflic acid
|Section1={{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 10331773
| InChI = 1/F5HOTe/c1-7(2,3,4,5)6/h6H
| InChIKey = OAOSLENTGBMCNC-UHFFFAOYAO
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/F5HOTe/c1-7(2,3,4,5)6/h6H
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = OAOSLENTGBMCNC-UHFFFAOYSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 57458-27-2
| PubChem = 15243876
| SMILES = F[Te](F)(F)(F)(F)O
}}
|Section2={{Chembox Properties
| Formula = {{chem2|HOTeF5}}
| H=1|O=1|Te=1|F=5
| Appearance = colorless solid
| pKa = 8.8 (in Ac2O){{cite book|title=Ionisation Constants of Inorganic Acids and Bases in Aqueous Solution|editor-first=D. D.|editor-last=Perrin|edition=2nd|series=IUPAC Chemical Data|issue=29|publisher=Pergamon|location=Oxford|year=1982|publication-date=1984|orig-date=1969|lccn=82-16524|isbn=0-08-029214-3|at=Entry 220}}
| MeltingPtC = 39.1
| BoilingPtC = 59.7
| Solubility =
}}
|Section3={{Chembox Hazards
| GHSPictograms = {{GHS05}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|314}}
| PPhrases = {{P-phrases|260|264|280|301+330+331|303+361+353|304+340|305+351+338|310|321|363|405|501}}
| MainHazards = corrosive, toxic
| FlashPt =
| AutoignitionPt =
}}
}}
Teflic acid is a chemical compound with the formula {{chem2|HOTeF5|auto=1}}. This strong acid is related to orthotelluric acid, {{chem2|Te(OH)6}}. Teflic acid has a slightly distorted octahedral molecular geometry.
Preparation
Teflic acid was accidentally discovered by Engelbrecht and Sladky. Their synthesis did not yield the anticipated telluryl fluoride {{chem2|TeO2F2}}, but a mixture of volatile telluric compounds, containing {{chem2|HOTeF5}}:Engelbrecht, A.; Sladky, F. "Pentafluoro-orthotellursaure, {{chem2|HOTeF5}}" Angewandte Chemie 1964. 76(9), 379-380, {{doi|10.1002/ange.19640760912}}.
:{{chem2|BaTeO4 + 10 FSO2OH → HOTeF5}} (25%)
Teflic acid can also be prepared from fluorosulfonic acid and barium tellurate:Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. {{ISBN|0-12-352651-5}}.
:{{chem2|5 FSO2OH + Ba(2+)[TeO2(OH)4](2−) → HOTeF5 + 4 H2SO4 + BaSO4}}
It is also the first hydrolysis product of tellurium hexafluoride:
:{{chem2|TeF6 + H2O → HOTeF5 + HF}}
Teflates
File:Boron-teflate-3D-balls.png
The conjugate base of teflic acid is called the teflate anion, {{chem2|F5TeO-}} (not to be confused with triflate). Many teflates are known, one example being {{chem2|B(OTeF5)3}}, that can be pyrolysed to give acid anhydride {{chem2|O(TeF5)2}}.
:{{chem2|2 B(OTeF5)3 → 2 B(OTeF5)2F + O(TeF5)2}}
The teflate anion is known to resist oxidation. This property has allowed the preparation several highly unusual species such as the hexateflates {{chem2|M(OTeF5)6-}} (in which M = As, Sb, Bi). Xenon forms the cation {{chem2|Xe(OTeF5)+}}.Mercier, H. P.A.; Sanders, J. C. P.; Schrobilgen, G. J. "The Hexakis(pentafluorooxotellurato)pnictate(V) Anions, {{chem2|M(OTeF5)6-}} (M = As, Sb, Bi): A Series of Very Weakly Coordinating Anions" Journal of the American Chemical Society, volume 116, 2921, (1994). {{doi|10.1021/ja00086a025}}.
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References
{{Reflist}}
Further reading
- R.B. King; Inorganic Chemistry of Main Group Elements, VCH Publishers, New York,1994.
{{Tellurium compounds}}