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Names | |||
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IUPAC name
Pentafluoroorthotelluric acid
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Other names
Teflic acid
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Identifiers | |||
3D model (
JSmol)
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ChemSpider | |||
ECHA InfoCard | 100.161.534 | ||
PubChem
CID
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CompTox Dashboard (
EPA)
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Properties | |||
HOTeF5 | |||
Molar mass | 239.60 g·mol−1 | ||
Appearance | colorless solid | ||
Melting point | 39.1 °C (102.4 °F; 312.2 K) | ||
Boiling point | 59.7 °C (139.5 °F; 332.8 K) | ||
Acidity (pKa) | 8.8 (in Ac2O) [1] | ||
Hazards | |||
Occupational safety and health (OHS/OSH): | |||
Main hazards
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corrosive, toxic | ||
GHS labelling: | |||
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Danger | |||
H314 | |||
P260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P405, P501 | |||
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
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Teflic acid is a chemical compound with the formula H O Te F5. This strong acid is related to orthotelluric acid, Te(OH)6. Teflic acid has a slightly distorted octahedral molecular geometry.
Teflic acid was accidentally discovered by Engelbrecht and Sladky. Their synthesis did not yield the anticipated telluryl fluoride TeO2F2, but a mixture of volatile telluric compounds, containing HOTeF5: [2]
Teflic acid can also be prepared from fluorosulfonic acid and barium tellurate: [3]
It is also the first hydrolysis product of tellurium hexafluoride:
The conjugate base of teflic acid is called the teflate anion, F5TeO− (not to be confused with triflate). Many teflates are known, one example being B(OTeF5)3, that can be pyrolysed to give acid anhydride O(TeF5)2. [3]
The teflate anion is known to resist oxidation. This property has allowed the preparation several highly unusual species such as the hexateflates M(OTeF5)−6 (in which M = As, Sb, Bi). Xenon forms the cation Xe(OTeF5)+. [4]