Oxygen difluoride

Oxygen difluoride
Other names difluorine monoxide fluorine monoxide oxygen fluoride hypofluorous anhydride
Identifiers
CAS number	7783-41-7 Y
PubChem	24547
ChemSpider	22953 Y
ChEBI	CHEBI:30494 Y
RTECS number	RS2100000
Jmol-3D images	Image 1
SMILES FOF
InChI InChI=1S/F2O/c1-3-2 Y Key: UJMWVICAENGCRF-UHFFFAOYSA-N Y InChI=1/F2O/c1-3-2 Key: UJMWVICAENGCRF-UHFFFAOYAI
Properties
Molecular formula	OF2
Molar mass	53.9962 g/mol
Appearance	colorless gas, pale yellow liquid when condensed
Density	1.9 g/cm3 as liquid at -145°C
Melting point	−223.8 °C
Boiling point	−144.8 °C
Solubility in other solvents	68 mL gaseous OF2 in 1 L (0 °C)[1]
Thermochemistry
Std enthalpy of formation ΔfHo298	24.5 kJ mol−1
Related compounds
Related compounds	HFO O2F2 Y difluoride (verify) (what is: Y/N?) 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 F₂O. As predicted by VSEPR theory, the molecule adopts a "V" shaped structure like H₂O, but it has very different properties, being a strong oxidizer.

Preparation

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.^[2][3] 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

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 (aq) → 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, SO₂F₂, and pyrosulfuryl fluoride, S₂O₅F₂:

OF₂ + 2 SO₂ → S₂O₅F₂

Popular culture

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

OF₂ is a dangerous chemical, as is the case for any strongly oxidizing gas.

References

1. ^ Yost, D. M. "Oxygen Fluoride" Inorganic Syntheses, 1939 volume, 1, pages 109-111.
2. ^ Paul Lebeau; Damiens, A. "A New Method for the Preparation of the Fluorine Oxide”Compt. rend. 1929, volume 188, 1253-5.
3. ^ Lebeau, P.; Damiens, A. "The Existence of an Oxygen Compound of Fluorine"Compt. rend. 1927, volume 185, pages 652-4.

External links

• National Pollutant Inventory - Fluoride and compounds fact sheet
• WebBook page for OF₂