Thionyl fluoride

Thionyl fluoride

Names
IUPAC name Thionyl fluoride
Identifiers
CAS Number	7783-42-8 N
3D model (JSmol)	Interactive image
ChemSpider	22954 Y
ECHA InfoCard	100.029.088
EC Number	231-997-2
PubChem CID	24548
UNII	2O8P7K5BE8
CompTox Dashboard (EPA)	DTXSID1064821
InChI InChI=1S/F2OS/c1-4(2)3 Y Key: LSJNBGSOIVSBBR-UHFFFAOYSA-N Y InChI=1/F2OS/c1-4(2)3 Key: LSJNBGSOIVSBBR-UHFFFAOYAL
SMILES FS(F)=O
Properties
Chemical formula	F2OS
Molar mass	86.06 g·mol−1
Appearance	colorless gas
Melting point	−110.5 °C (−166.9 °F; 162.7 K)
Boiling point	−43.8 °C (−46.8 °F; 229.3 K)
Solubility in water	hydrolysis
Solubility	soluble in ethanol, ether, benzene
Vapor pressure	75.7 kPa (-50 °C)[1]
Structure
Molecular shape	trigonal pyramidal
Thermochemistry
Std molar entropy (S⦵298)	278.6 J/mol·K[2]
Std enthalpy of formation (ΔfH⦵298)	-715 kJ/mol[2]
Std enthalpy of combustion (ΔcH⦵298)	56.8 J/mol·K[2]
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H300, H310, H314, H330
Precautionary statements	P260, P262, P264, P270, P271, P280, P284, P301+P310, P301+P330+P331, P302+P350, P303+P361+P353, P304+P340, P305+P351+P338, P310, P320, P321, P322, P330, P361, P363, P403+P233, P405, P501
Related compounds
Related oxohalides	Thionyl chloride Thionyl bromide
Related compounds	Nitrosyl fluoride Carbonyl fluoride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Thionyl fluoride is the inorganic compound with the formula SOF
₂. This colourless gas is mainly of theoretical interest, but it is a product of the degradation of sulfur hexafluoride, an insulator in electrical equipment. The molecule adopts a distorted pyramidal structure, with C_s symmetry. The S-O and S-F distances are 1.42 and 1.58 Å, respectively. The O-S-F and F-S-F angles are 106.2 and 92.2°, respectively. Thionyl chloride and thionyl bromide have similar structures, although these compounds are liquid at room temperature. Mixed halides are also known, such as SOClF, thionyl chloride fluoride.^[3]

Synthesis and reactions

Thionyl fluoride can be produced by the reaction of thionyl chloride with fluoride sources such as antimony trifluoride.^[4][5]

3 SOCl₂ + 2SbF₃ → 3SOF₂ + 2SbCl₃

Alternatively, it arises via the fluorination of sulfur dioxide:^[5]

SO₂ + PF₅ → SOF₂ + POF₃

Thionyl fluoride arises as a fleeting intermediate from the decomposition of sulfur hexafluoride as the result of electrical discharges which generate sulfur tetrafluoride. SF₄ hydrolyzes to give thionyl fluoride, which in turn hydrolyzes further as described below.^[6]

As expected from the behavior of the other thionyl halides, this compound hydrolyzes readily, giving hydrogen fluoride and sulfur dioxide:^[5]

SOF₂ + H₂O → 2 HF + SO₂

In contrast to thionyl chloride and bromide, thionyl fluoride is not useful for halogenation. The related derivative, sulfur tetrafluoride is however useful for that purpose.

References

External links

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