Oxygen difluoride

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Oxygen difluoride
Oxygen difluoride Oxygen difluoride
Systematic name oxygen(II) fluoride
Other names difluorine monoxide
fluorine monoxide
oxygen difluoride
oxygen fluoride
Molecular formula OF2
Molar mass 53.9962 g mol−1
CAS number [7783-41-7]
Density 2.26 kg dm−3
Solubility (in water) 68 mL gaseous OF2 in 1 L (0 °C)[1]
Melting point −224 °C
Boiling point −145 °C
Color red-brown (gas)
pale yellow (liquid)
Heat of formation, ΔHf° 24.5 kJ mol−1
Average O−F bond energy 187 kJ mol−1
Related compounds O2F2
NHF2
NF3
SCl2
Disclaimer and references

Oxygen difluoride is the chemical compound with the formula OF2. It is a powerful oxidant and fluorinating agent. The oxygen atom has an oxidation number of +2, unlike almost all other oxygen compounds, where it is −2. The only exceptions are peroxides, with oxygen in the −1 oxidation state (e.g. hydrogen peroxide, H2O2), superoxides, with oxygen in the −½ oxidation state (e.g. sodium superoxide, NaO2) and dioxygen difluoride, O2F2, in which oxygen adopts an oxidation state of +1.

Contents

[edit] 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:

2F2 + 2NaOH → OF2 + 2NaF + H2O

[edit] Reactions

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, yielding XeF4 and xenon oxyfluorides.

Oxygen difluoride reacts very slowly with water to form hydrofluoric acid:

OF2(aq) + H2O(aq) → 2HF(aq) + O2(g)

[edit] 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.

[edit] Safety

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

[edit] References

  1. ^ Yost, D. M. "Oxygen Fluoride" Inorganic Syntheses, 1939 volume, 1, pages 109-111.
  2. ^ Lebeau, P.; 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.

[edit] External links

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