Sulfuryl fluoride
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| Sulfuryl fluoride | |
|---|---|
| Image:Sulfuryl fluoride.jpg | |
| General | |
| Systematic name | Sulfuryl fluoride |
| Other names | ? |
| Molecular formula | F2O2S |
| SMILES | ? |
| Molar mass | ?.?? g/mol |
| Appearance | colourless gas |
| CAS number | [2699-79-8] |
| Properties | |
| Density and phase | 1.623 g/cm³ at 0 °C |
| Solubility in water | low |
| Other solvents | SO2 |
| Melting point | -135.7 °C |
| Boiling point | -55.2 °C |
| Viscosity | ? cP at ? °C |
| Structure | |
| Coordination geometry |
tetrahedral |
| Crystal structure | |
| Dipole moment | ? D |
| Hazards | |
| MSDS | External MSDS |
| Main hazards | toxic |
| NFPA 704 | |
| R/S statement | R: ? S: ? |
| RTECS number | ? |
| Supplementary data page | |
| Structure and properties |
n, εr, etc. |
| Thermodynamic data |
Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Related compounds | |
| Related compounds | SO2Cl2, SO2ClF, SF6, SO3 |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
|
Sulfuryl fluoride is the chemical compound with the formula SO2F2. This inorganic gas has properties more similar to sulfur hexafluoride than sulfuryl chloride, being resistant to hydrolysis by water even up to 150 °C. So inert is this material that suspended molten "sodium metal retains its shiny metallic appearance."[1]
Contents |
[edit] Structure and preparation
The molecule is tetrahedral with C2v symmetry. The S-O distance is 140.5 pm, S-F is 153.0 pm. As predicted by VSEPR, the O-S-O angle is more open than the F-S-F angle, 124° and 97°, respectively.[1]
It is prepared by direct reaction of fluorine with sulfur dioxide:
- SO2 + F2 → SO2F2
A laboratory-scale synthesis begins with the preparation of potassium fluorosulfite:[2]
- SO2 + KF → KSO2F
This salt is then chlorinated to give sulfuryl chloride fluoride:
- KSO2F + Cl2 → SO2ClF + KCl
Further heating (180 °C) of potassium fluorosulfite with the sulfuryl chloride fluoride gives the desired product:[3]
- SO2ClF + KSO2F → SO2F2 + KCl + SO2
Heating metal fluorosulfonate salts also gives this molecule:[1]
- Ba(OSO2F)2 → BaSO4 + SO2F2
[edit] Use as a fumigant
SO2F2 is of interest as a fumigant with the phase-out of methyl bromide and in view of the risks of phosphine.[4]
[edit] "Vikane"
Developed by the Dow Chemical Company under the trade name Vikane, SO2F2 is used as a structural fumigant insecticide to control dry-wood termites. During application, the building is enclosed in a tight tent and filled with the gas for a period of time, usually at least 20 hours. The building must be ventilated, generally for at least 6 hours before occupants can return. Vikane is colorless, odorless, and leaves no residue. During the fumigation process, a warning agent similar to tear gas is first released into the building to ensure that no occupants remain. Pest control experts claim Vikane is the only effective treatment for drywood termites. However, since it leaves no residue Vikane provides no protect from future infestation. Dow recently has begun marketing Vikane as a post-harvest fumigant for dry fruits, nuts, and grains under the trade name ProFume. [1]
[edit] References
- ^ a b c Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
- ^ Seel, F. "Potassium Fluorosulfite" Inorganic Syntheses 1967, IX, pages 113-115.
- ^ Seel, F. "Sulfuryl Chloride Fluoride and Sufluryl Fluoride" Inorganic Syntheses 1967, IX, pages 11-113.
- ^ Bell, C. H. "Fumigation in the 21st century" "Crop Protection, 2000, 19, 563-569. ISSN 0261-2194. AN 2000:895590
