Oxygen difluoride
| Oxygen difluoride | |
|---|---|
 |
|
 |
|
|
Other names
oxygen fluoride |
|
| Identifiers | |
| CAS number | 7783-41-7  |
| PubChem | 24547 |
| ChemSpider | 22953 |
| ChEBI | CHEBI:30494 |
| RTECS number | RS2100000 |
| Jmol-3D images | Image 1 |
|
|
|
|
| Properties | |
| Molecular formula | OF2 |
| Molar mass | 53.9962 g/mol |
| Appearance | colorless gas, pale yellow liquid when condensed |
| Odor | peculiar, foul odor |
| Density | 1.90 g/cm3 (-224° C, liquid), 1.719 g/cm3 (-183° C, liquid), 1.521 g/cm3 (liquid at −145 °C), 1.88 g/l (gas at room temperature) |
| Melting point |
−223.8 °C, 49 K, -371 °F |
| Boiling point |
−144.75 °C, 128 K, -229 °F |
| Solubility in water | hydrolyzes[1] |
| Solubility in other solvents | 68 mL gaseous OF2 in 1 L (0 °C)[2] |
| Thermochemistry | |
| Std enthalpy of formation ΔfH |
24.5 kJ mol−1 |
| Related compounds | |
| Related compounds | HFO O2F2 NHF2 NF3 SCl2 |
 (verify) (what is:  / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
|
| Infobox references | |
Oxygen difluoride is the chemical compound with the formula OF2. As predicted by VSEPR theory, the molecule adopts a "V" shaped structure like H2O, but it has very different properties, being a strong oxidizer.
Contents |
Preparation[edit]
Oxygen difluoride was first reported in 1929; it was obtained by the electrolysis of molten potassium fluoride and hydrofluoric acid containing small quantities of water.[3][4] The modern preparation entails the reaction of fluorine with a dilute aqueous solution of sodium hydroxide, with sodium fluoride as a side-product:
- 2 F2 + 2 NaOH → OF2 + 2 NaF + H2O
Reactions[edit]
Its powerful oxidizing properties are suggested by the oxidation number of +2 for the oxygen atom, which is unusual. Above 200 °C, OF2 decomposes to oxygen and fluorine via a radical mechanism.
OF2 reacts with many metals to yield oxides and fluorides. Nonmetals also react: phosphorus reacts with OF2 to form PF5 and POF3; sulfur gives SO2 and SF4; and unusually for a noble gas, xenon reacts, at elevated temperatures, yielding XeF4 and xenon oxyfluorides.
Oxygen difluoride reacts very slowly with water to form hydrofluoric acid:
- OF2 (aq) + H2O (l) → 2 HF (aq) + O2 (g)
Oxygen difluoride oxidizes sulfur dioxide to sulfur trioxide:
- OF2 + SO2 → SO3 + F2
However, in the presence of UV radiation the products are sulfuryl fluoride, SO
2F
2, and pyrosulfuryl fluoride, S
2O
5F
2:
- OF2 + 2 SO2 → S
2O
5F
2
Popular culture[edit]
In Robert L. Forward's science fiction novel Camelot 30K, oxygen difluoride was used as a biochemical solvent by fictional life forms living in the solar system's Kuiper belt.
Safety[edit]
OF2 is a dangerous chemical, as is the case for any strongly oxidizing gas.
References[edit]
- ^ http://www.chemyq.com/En/xz/xz1/2818mqnrv.htm
- ^ Yost, D. M. "Oxygen Fluoride" Inorganic Syntheses, 1939, volume 1, pages 109–111.
- ^ Lebeau, P.; Damiens, A. (1929). "Sur un nouveau mode de préparation du fluorure d'oxygène" [A new method of preparation of oxygen fluoride]. Comptes rendus hebdomadaires des séances de l’Académie des sciences (in French) 188: 1253–1255. Retrieved February 21, 2013.
- ^ Lebeau, P.; Damiens, A. (1927). "Sur l'existence d'un composé oxygéné du fluor" [The existence of an oxygen compound of fluorine]. Comptes rendus hebdomadaires des séances de l’Académie des sciences (in French) 185: 652–654. Retrieved February 21, 2013.
