Oxygen difluoride

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Oxygen difluoride
Structure and dimensions of the oxygen difluoride molecule
Space-filling model of the oxygen difluoride molecule
Names
IUPAC name
Oxygen difluoride
Other names
  • Oxygen fluoride
  • Hypofluorous anhydride
Identifiers
3D model (
JSmol
)
ChEBI
ChemSpider
ECHA InfoCard
 100.029.087 Edit this at Wikidata
EC Number
  • 231-996-7
RTECS number
  • RS2100000
UNII
  • InChI=1S/F2O/c1-3-2 checkY
    Key: UJMWVICAENGCRF-UHFFFAOYSA-N checkY
  • InChI=1/F2O/c1-3-2
    Key: UJMWVICAENGCRF-UHFFFAOYAI
  • FOF
Properties
OF2
Molar mass 53.9962 g/mol
Appearance colorless gas, pale yellow liquid when condensed
Odor peculiar, foul
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 (−370.8 °F; 49.3 K)
Boiling point −144.75 °C (−228.55 °F; 128.40 K)
hydrolyzes[1] slowly
Vapor pressure 48.9 atm (at −58.0 °C or −72.4 °F or 215.2 K[a])
Thermochemistry
43.3 J/mol K
246.98 J/mol K
Std enthalpy of
formation
(ΔfH⦵298)
 −24.5 kJ mol−1
42.5 kJ/mol
Hazards
GHS labelling:[4]
GHS03: OxidizingGHS04: Compressed GasGHS05: CorrosiveGHS06: Toxic
Danger
H270, H280, H314, H330
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 0: Will not burn. E.g. waterInstability 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g. hydrogen peroxideSpecial hazard OX: Oxidizer. E.g. potassium perchlorate
4
0
3
OX
Lethal dose or concentration (LD, LC):
  • 2.6 ppm (rat, 1 hour)
  • 1.5 ppm (mouse, 1 hour)
  • 26 ppm (dog, 1 hour)
  • 16 ppm (monkey, 1 hour)
[3]
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 0.05 ppm (0.1 mg/m3)[2]
REL (Recommended)
 C 0.05 ppm (0.1 mg/m3)[2]
IDLH
(Immediate danger)
 0.5 ppm[2]
Related compounds
Related compounds
  • I2O
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Oxygen difluoride is a

oxidizer and has attracted attention in rocketry for this reason.[5] With a boiling point of −144.75 °C, OF2 is the most volatile (isolable) triatomic compound.[6] The compound is one of many known oxygen fluorides
.

Preparation

Oxygen difluoride was first reported in 1929; it was obtained by the electrolysis of molten

water.[7][8] 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

Structure and bonding

It is a covalently bonded molecule with a

oxidation number of +2 for the oxygen
atom instead of its normal −2.

Reactions

Above 200 °C, OF2 decomposes to oxygen and fluorine by a radical mechanism.

2 OF2 → O2 + 2 F2

OF2 reacts with many metals to yield

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 + H2O → 2 HF + O2

It can oxidize

sulphur dioxide to sulfur trioxide and elemental fluorine
:

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

Safety

Oxygen difluoride is considered an unsafe gas due to its oxidizing properties. Hydrofluoric acid produced by the hydrolysis of OF2 with water is highly corrosive and toxic, capable of causing necrosis, leaching calcium from the bones and causing cardiovascular damage, among a host of other highly toxic effects.

Popular culture

In

radiothermal
heating.

Notes

  1. critical temperature, which is below ordinary room temperature
    .

References

  1. ^ "difluorine monoxide; oxygen difluoride, physical properties, suppliers, CAS, MSDS, structure, Molecular Formula, Molecular Weight, Solubility, boiling point, melting point". www.chemyq.com.
  2. ^ a b c NIOSH Pocket Guide to Chemical Hazards. "#0475". National Institute for Occupational Safety and Health (NIOSH).
  3. ^ "Oxygen difluoride". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  4. ^ GHS: GESTIS 570242
  5. ^ "Oxygen Difluoride - an overview | ScienceDirect Topics". www.sciencedirect.com. Retrieved 2023-11-03.
  6. ISBN 978-0-08-037941-8
    .
  7. Comptes rendus hebdomadaires des séances de l'Académie des Sciences
    (in French). 188: 1253–1255. Retrieved February 21, 2013.
  8. Comptes rendus hebdomadaires des séances de l'Académie des Sciences
    (in French). 185: 652–654. Retrieved February 21, 2013.

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Oxygen_difluoride&oldid=1196092052"