Formula HF5OTe Melting point 39.1 °C | Boiling point 59.7 °C Appearance colorless solid | |
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Teflic acid is the chemical compound with the formula HOTeF5. This strong acid is related to orthotelluric acid, Te(OH)6. Teflic acid has octahedral geometry and, Ignoring its bent Te-O-H bond, has point group symmetry C4v.
Contents
Preparation
Teflic acid can be prepared from barium tellurate and fluorosulfonic acid:
5HOSO2F + BaO2Te(OH)4 → HOTeF5 + 4 H2SO4 + BaSO4It is also the first hydrolysis product of tellurium hexafluoride:
TeF6 + H2O → HOTeF5 + HFTeflates
The conjugate base of teflic acid is called the teflate anion, F5TeO− (not to be confused with triflate). Many teflates are known, examples being B(OTeF5)3 and the acid anhydride O(TeF5)2. Pyrolysis of the boron compound gives the dimer (TeF4O)2
2 B(OTeF5)3 → 2 B(OTeF5)2F + (OTeF4)2The teflate anion is known to resist oxidation. This property has allowed the preparation several highly unusual species such as the hexateflates M(OTeF5)6− (M = As, Sb, Bi). Xenon forms the cation Xe(OTeF5)+,