- Sulfuryl fluoride
Chembox new
Name = Sulfuryl fluoride
ImageFile = Sulfuryl-fluoride-2D-dimensions.png
ImageName = Sulfuryl fluoride
ImageFile1 = Sulfuryl-fluoride-3D-balls.png
ImageName1 = Sulfuryl fluoride
IUPACName = Sulfuryl fluoride
OtherNames = Sulfonyl fluoride; Sulfur dioxide difluoride;Sulphuryl fluoride; Sulfuryl difluoride
Section1 = Chembox Identifiers
SMILES =
CASNo = 2699-79-8
RTECS =
Section2 = Chembox Properties
Formula = SO2F2
MolarMass = 102.06 g/mol
Appearance = colourless gas
Density = 1.623 g/cm³ at 0 °C
Solubility = low
Solvent = other solvents
SolubleOther = SO2
MeltingPt = -135.7 °C
BoilingPt = -55.2 °C
Viscosity =
Section3 = Chembox Structure
Coordination = tetrahedral
CrystalStruct =
Dipole =
Section7 = Chembox Hazards
ExternalMSDS =
MainHazards = toxic
RPhrases =
SPhrases =
Section8 = Chembox Related
OtherCpds = SO2Cl2,
SO2ClF,
SF6,
SO3Sulfuryl fluoride is the
chemical compound with the formula SO2F2. Thisinorganic gas has properties more similar tosulfur hexafluoride thansulfuryl chloride , being resistant tohydrolysis even up to 150 °C. So inert is this material that suspended molten "sodium metal retains its shiny metallic appearance."Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.]tructure 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.It is prepared by direct reaction of
fluorine withsulfur dioxide ::SO2 + F2 → SO2F2A laboratory-scale synthesis begins with the preparation of potassium fluorosulfite: [Seel, F. "Potassium Fluorosulfite" Inorganic Syntheses 1967, IX, pages 113-115.] :SO2 + KF → KSO2FThis salt is then chlorinated to give
sulfuryl chloride fluoride ::KSO2F + Cl2 → SO2ClF + KClFurther heating (180 °C) of potassium fluorosulfite with the sulfuryl chloride fluoride gives the desired product: [Seel, F. "Sulfuryl Chloride Fluoride and Sufluryl Fluoride" Inorganic Syntheses 1967, IX, pages 11-113.] :SO2ClF + KSO2F → SO2F2 + KCl + SO2Heating metal fluorosulfonate salts also gives this molecule::Ba(OSO2F)2 → BaSO4 + SO2F2
Use as a fumigant
SO2F2 is of interest as a fumigant with the phase-out of
methyl bromide and in view of the risks ofphosphine . [Bell, C. H. "Fumigation in the 21st century" "Crop Protection, 2000, 19, 563-569. ISSN 0261-2194. AN 2000:895590]Originally developed by the
Dow Chemical Company , SO2F2 (sulfuryl fluoride) is in widespread use as a structural fumigantinsecticide to control drywoodtermite s, particularly in warm-weather portions of the southwestern and southeastern United States and in Hawaii. Less commonly, it can also be used to control rodents, powder-post beetles, bark beetles, and bedbugs.Sulfuryl fluoride is currently marketed by three distinct manufacturers, under four different brand names. "Vikane" (Dow) (EPA Reg. No. 62719- 4-ZA) has been commercially available since the early 1960s, with "Zythor" (marketed by competitor EnSystex II of North Carolina) (EPA Reg. No. 81824- 1-AA) being more recently introduced gradually as its use is approved by individual states (in Florida circa 2004, but not in California until October 2006, for example). Dow recently has begun marketing sulfuryl fluoride as a post-harvest fumigant for dry fruits, nuts, and grains under the trade name "ProFume" (EPA Reg. No. 62719- 376-AA). [http://www.dowagro.com/profume/index.htm] Most recently Drexel Chemical Company has registered "Master Fume" (EPA Reg. No. 19713-596-AA) for the structural market, competing against "Vikane" and "Zythor". [ [http://www.cdpr.ca.gov/cgi-bin/label/labq.pl?p_chem=618&activeonly=on Output Reporting ] ]
During application, the building is enclosed in a tight tent and filled with the gas for a period of time, usually at least 16-18 hours, sometimes as long as 72 hours. The building must then be ventilated, generally for at least 6 hours, before occupants can return. Sulfuryl fluoride is colorless, odorless, and leaves no residue. During the fumigation process, a warning agent called
Chloropicrin (similar totear gas , but more toxic) is first released into the building to ensure that no occupants remain.Some
pest control experts claim sulfuryl fluoride is the only effective treatment for drywoodtermites . (Heat is the only other approved method for whole structure treatment for termites in California. [ [http://www.pestboard.ca.gov/forms/factsheets/termites.pdf Termites Fact Sheet ] ] ) Because it leaves no residue sulfuryl fluoride provides no protection from future infestations, although heavy reinfestation can take several years since drywood termites have slower growing colonies than ground termites.afety considerations
Sulfuryl fluoride must be transported in a vehicle marked with "Inhalation Hazard 2" placards. Most U.S. states also require a license or certification for the individual applying the fumigant.
References
External links
* [http://npic.orst.edu/factsheets/sftech.pdf Sulfuryl Fluoride Technical Fact Sheet - National Pesticide Information Center]
* [http://npic.orst.edu/factsheets/sfgen.pdf Sulfuryl Fluoride General Fact Sheet - National Pesticide Information Center]
* [http://extoxnet.orst.edu/pips/sulfuryl.htm Sulfuryl Fluoride Pesticide Information Profile - Extension Toxicology Network]
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