Chemistry:Trifluorosulfite
Trifluorosulfite is an anion containing sulfur in a +4 oxidation state, three fluorine atoms and one oxygen atom with formula [SOF3]−. It may form salts with cations with low fluoride affinity.
Preparation
Trifluorosulfite salts can be made by reacting a fluoride salt with thionyl fluoride SOF2 at or below room temperature.[1]
MF + SOF2 → MSOF3
Fluorosulfite may be fluoronated in a compound to yield triflurosulfite.[2]
In the gas phase SOF4 could add an electron to form SOF4− which in a collision would break up to mostly form SOF3−.[3]
Properties
Shape
The shape is a distorted trigonal bipyrimid. Two fluorines and the sulfur are almost colinear, and those fluorine atoms are called "axial", At fight angles to this axis are the equatorial oxygen and fluorine. A lone pair of electrons is opposite these. The symmetry of the molecule is Cs.[1]
The bond lengths are calculated as S-Faxial = 1.79 Å; S-F equatorial = 1.60 Å; S=O = 1.43 Å. The angles between the bonds are ∠(O=S-Fequatorial)=106.7° and ∠(Faxial-S-Faxial)=166.5° (so not quite a 180° straight line).[4]
spectrum
The infrared spectrum shows absorption lines at 1189 cm−1 due to S=O vibration, 725 from S-F equatorial vibration , 504 from S-F axial vibration. 403 OSF equatorial scissor, 383 OSF equatorial rock. The Raman spectrum has a few more lines. Trifluorosulfite salts can dissolve in acetonitrile and other polar solvents.
Reactions
Trifluorosulfite salts react with water to form fluorosulfite and sulfite compounds. It also reacts with liquid sulfur dioxide to yield a fluorosulfite.
In the gas phase the trifluorosulfite ion reacts with phosphorus trifluoride, boron trifluoride, silicon tetrafluoride, and sulfur dioxide to form fluoronated ions and thionyl fluoride.[3]
Related
Related anions include trifluorosulfate [SO2F3]−,[5] pentafluorosulfite SF5−, and fluorosulfite [SO2F]−.
List
| formula | comment | ref |
|---|---|---|
| Me4N+SOF3- | [1] | |
| trans-[Pt(F)(SOF3)(PCy3)2] | below 283K | [2] |
References
- ↑ 1.0 1.1 1.2 Kornath, Andreas; Kadzimirsz, Daniel; Ludwig, Ralf (1 June 1999). "Trifluorosulfite Anion, SOF 3 -". Inorganic Chemistry 38 (13): 3066–3069. doi:10.1021/ic9809005.
- ↑ 2.0 2.1 Jaeger, Ruben; He, Ouchan; Sander, Stefan; Dirican, Dilcan; Ahrens, Mike; Braun, Thomas (2025-06-02). "Routes to Pt Derivatives of High‐Valent Sulfur Oxofluorides S(═O) 2 F, S(═O)F 2 , and S(═O)F 3 by Fluorination and Oxygenation" (in en). Angewandte Chemie International Edition 64 (23). doi:10.1002/anie.202503153. ISSN 1433-7851. PMID 40146430. PMC 12124436. https://onlinelibrary.wiley.com/doi/10.1002/anie.202503153.
- ↑ 3.0 3.1 Arnold, Susan T.; Miller, Thomas M.; Viggiano, A. A. (1 October 2002). "A Combined Experimental and Theoretical Study of Sulfur Oxyfluoride Anion and Neutral Thermochemistry and Reactivity". The Journal of Physical Chemistry A 106 (42): 9900–9909. doi:10.1021/jp020557w.
- ↑ Baran, Enrique J (January 2001). "Mean amplitudes of vibration of the trifluorosulfite anion". Journal of Fluorine Chemistry 107 (1): 35–37. doi:10.1016/S0022-1139(00)00396-1.
- ↑ Hohenstein, Christian; Kadzimirsz, Daniel; Ludwig, Ralf; Kornath, Andreas (17 January 2011). "Synthesis and Characterization of Tetramethylammonium Trifluorosulfate". Chemistry – A European Journal 17 (3): 925–929. doi:10.1002/chem.201000102.
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