Thionyl fluoride is the
inorganic compound with the
formula . 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
Thionyl chloride is an inorganic compound with the chemical formula . It is a moderately volatile, colourless liquid with an unpleasant acrid odour. Thionyl chloride is primarily used as a chlorinating reagent, with approximately per year bein ...
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.
Synthesis and reactions
Thionyl fluoride can be produced by the reaction of
thionyl chloride
Thionyl chloride is an inorganic compound with the chemical formula . It is a moderately volatile, colourless liquid with an unpleasant acrid odour. Thionyl chloride is primarily used as a chlorinating reagent, with approximately per year bein ...
with fluoride sources such as
antimony trifluoride
Antimony trifluoride is the inorganic compound with the formula SbF3. Sometimes called Swarts' reagent, is one of two principal fluorides of antimony, the other being SbF5. It appears as a white solid. As well as some industrial applications, i ...
.
[W. C. Smith, E. L. Muetterties "Thionyl Fluoride" ''Inorganic Syntheses'' 1960, Volume 6, pages: 162-163. ][
]
:3 SOCl
2 + 2
SbF3 → 3SOF
2 + 2
SbCl3
Alternatively, it arises via the fluorination of
sulfur dioxide:
:SO
2 + 2
PF5 → SOF
2 + POF
3
Thionyl fluoride arises as a fleeting intermediate from the decomposition of sulfur hexafluoride as the result of electrical discharges which generate
sulfur tetrafluoride. SF
4 hydrolyzes to give thionyl fluoride, which in turn hydrolyzes further as described below.
[
]
As expected from the behavior of the other thionyl halides, this compound hydrolyzes readily, giving
hydrogen fluoride and
sulfur dioxide:
:SOF
2 + H
2O → 2 HF + SO
2
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
{{fluorine compounds
Thionyl compounds
Oxyfluorides
Sulfur(IV) compounds
Sulfur oxohalides