\n| Density = 4.172 g/L (gas), 1.632 g/mL (liquid under compressed gas at 0 °C)\n| Solubility = 0.2% (0°C)\n| Solvent = other solvents\n| SolubleOther = SO2\n| MeltingPtC = -124.7\n| BoilingPtC = -55.4\n| Viscosity = \n| VaporPressure = 15.8 atm (21°C)\n }}"},"Section3":{"wt":"{{Chembox Structure\n| Coordination = tetrahedral\n| CrystalStruct =\n| Dipole =\n }}"},"Section7":{"wt":"{{Chembox Hazards\n| ExternalSDS =\n| MainHazards = neurotoxin\n| HPhrases = \n| PPhrases = \n| GHS_ref = \n| NFPA-H = 3\n| NFPA-F = 0\n| NFPA-R = 1\n| NFPA-S =\n| IDLH = 200 ppm{{PGCH|0581}}\n| REL = TWA 5 ppm (20 mg/m3) ST 10 ppm (40 mg/m3)\n| PEL = TWA 5 ppm (20 mg/m3)\n| LC50 = 991 ppm (rat, 4 hr){{IDLH|2699798|Sulfuryl fluoride}} \n| LCLo = 1200 ppm (mouse, 1 hr)
5000 ppm (rabbit, 1 hr)\n }}"},"Section8":{"wt":"{{Chembox Related\n| OtherCations = [[Selenoyl fluoride|SeO2F2]]\n| OtherAnions = [[Sulfuryl chloride|SO2Cl2]],
[[sulfuryl chloride fluoride|SO2ClF]]\n| OtherCompounds = [[sulfur hexafluoride|SF6]],
[[Sulfur trioxide|SO3]]
[[Trifluorosulfate|SO2F3−]]\n }}"}},"i":1}}]}" id="mwAg">
Names | |||
---|---|---|---|
IUPAC name Sulfuryl fluoride | |||
Other names Sulfonyl fluoride; Sulfur dioxide difluoride; Sulphuryl fluoride; Sulfuryl difluoride; Vikane; Zythor | |||
Identifiers | |||
3D model (JSmol) | |||
ChEBI | |||
ChemSpider | |||
ECHA InfoCard | 100.018.437 | ||
PubChem CID | |||
UNII | |||
CompTox Dashboard (EPA) | |||
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| |||
Properties | |||
SO2F2 | |||
Molar mass | 102.06 g/mol | ||
Appearance | colourless gas | ||
Odor | odorless [1] | ||
Density | 4.172 g/L (gas), 1.632 g/mL (liquid under compressed gas at 0 °C) | ||
Melting point | −124.7 °C (−192.5 °F; 148.5 K) | ||
Boiling point | −55.4 °C (−67.7 °F; 217.8 K) | ||
0.2% (0°C) [1] | |||
Solubility in other solvents | SO2 | ||
Vapor pressure | 15.8 atm (21°C) [1] | ||
Structure | |||
tetrahedral | |||
Hazards | |||
Occupational safety and health (OHS/OSH): | |||
Main hazards | neurotoxin | ||
NFPA 704 (fire diamond) | |||
Lethal dose or concentration (LD, LC): | |||
LC50 (median concentration) | 991 ppm (rat, 4 hr) [2] | ||
LCLo (lowest published) | 1200 ppm (mouse, 1 hr) 5000 ppm (rabbit, 1 hr) [2] | ||
NIOSH (US health exposure limits): | |||
PEL (Permissible) | TWA 5 ppm (20 mg/m3) [1] | ||
REL (Recommended) | TWA 5 ppm (20 mg/m3) ST 10 ppm (40 mg/m3) [1] | ||
IDLH (Immediate danger) | 200 ppm [1] | ||
Related compounds | |||
Other anions | SO2Cl2, SO2ClF | ||
Other cations | SeO2F2 | ||
Related compounds | SF6, SO3 SO2F3− | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Sulfuryl fluoride (also spelled sulphuryl fluoride) is an inorganic compound with the formula SO2F2. It is an easily condensed gas and has properties more similar to sulfur hexafluoride than sulfuryl chloride, being resistant to hydrolysis even up to 150 °C. [3] It is neurotoxic and a potent greenhouse gas, but is widely used as a fumigant insecticide to control termites.
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. [3]
One synthesis begins with the preparation of potassium fluorosulfite: [4]
This salt is then chlorinated to give sulfuryl chloride fluoride:
Further heating at 180 °C of potassium fluorosulfite with the sulfuryl chloride fluoride gives the desired product: [5]
Heating metal fluorosulfonate salts also gives this molecule: [3]
It can be prepared by direct reaction of fluorine with sulfur dioxide:
On a laboratory scale, sulfuryl fluoride has been conveniently prepared from 1,1'-sulfonyldiimidazole, in the presence of potassium fluoride and acid. [6] [7]
Sulfuryl fluoride is unreactive toward molten sodium metal. [3] Similarly it is slow to hydrolyze, but eventually converts to sulfur trioxide. [8] [9]
Sulfuryl fluoride gas is a precursor to fluorosulfates and sulfamoyl fluorides: [10]
Originally developed by the Dow Chemical Company, sulfuryl fluoride is in widespread use as a structural fumigant insecticide to control drywood termites, particularly in warm-weather portions of the southwestern and southeastern United States and in Hawaii. It has a non-specific mode of action (IRAC group 8C). Less commonly, it can also be used to control rodents, powderpost beetles, deathwatch beetles, bark beetles, and bedbugs. Its use has increased as a replacement for methyl bromide, which was phased out because of harm to the ozone layer. It is an alternative to the use of phosphine, which is acutely toxic. [11]
During application, the building is enclosed 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. California regulations are such that the tent will be on for three to five days, which includes ventilation. In the US, sulfuryl fluoride must be transported in a vehicle marked with "Inhalation Hazard 2" placards. [12] [13] Most states require a license or certification for the individual applying the fumigant.
The concentration is continuously monitored and maintained at the specified level using electronic equipment. Possible leakages are also checked by low range electronic detectors. Reentry to the home is allowed when the concentration level is at or below 5 ppm. [14] Sulfuryl fluoride is colorless and odorless, however, during the fumigation process, a warning agent called chloropicrin is first released into the building to ensure that no occupants remain. Tent fumigation is the most effective treatment for the extermination of known and unknown infestations of wood-destroying insects. Heat is the only other approved method for whole structure treatment for termites in California. [15] Sulfuryl fluoride provides no protection from future infestations, although heavy re-infestation can take several years since drywood termites have slower growing colonies than ground termites.
Sulfuryl fluoride is marketed in the U.S. by three 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 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). Sulfuryl fluoride has been marketed as a post-harvest fumigant for dry fruits, nuts, and grains under the trade name ProFume (U.S. EPA Reg. No. 62719- 376-AA). [16] Most recently Drexel Chemical Company has registered Master Fume (EPA Reg. No. 19713-596-AA) for the structural market, competing against Vikane and Zythor. [17]
Inhalation of sulfuryl fluoride is hazardous and may result in respiratory irritation, pulmonary edema, nausea, abdominal pain, central nervous system depression, numbness in the extremities, muscle twitching, seizures, and death. [18] [19] [20] These high exposures occurred when people entered into structures illegally during fumigation or after insufficient aeration. Epidemiological studies showed that fumigation workers who used sulfuryl fluoride showed neurological effects, which included reduced performance on cognitive tests and pattern memory tests, and reduced olfactory function. [21]
In 1987, an elderly couple was exposed to sulfuryl fluoride in their house already cleared for reentry. [21] While the fumigation company opened windows and doors, and aerated the house with fans, sulfuryl fluoride level was not measured. It was not detected when the air was sampled 12 days after aeration. The couple experienced weakness, nausea and shortness of breath that evening. The man suffered a seizure and died the following day. His wife's condition got worse with pulmonary edema, and she died after a cardiovascular arrest 6 days later.
In 2015, a 10-year-old boy suffered severe brain damage and lost function of his left arm and leg after his home was treated with sulfuryl fluoride and insufficiently aerated, prompting a criminal investigation by the Department of Justice and the Florida Department of Agricultural and Consumer Services. [22] Two pest control workers later pled guilty to charges of misuse of the pesticide resulting in the boy's poisoning, and were each sentenced to one year in prison. [23]
In 2016, a 24-year-old man who allegedly entered an apartment that was being fumigated in Fremont, California to commit a burglary was exposed to sulfuryl fluoride and chloropicrin and died shortly thereafter. According to a police officer, he experienced labored breathing and was sweating before he collapsed just a few steps from the first floor window of the apartment he allegedly burglarized. [24]
In April 2024, In Pompano Beach Florida, two company pesticide workers died. The owner was also hospitalized but survived. [25]
Based on the first high frequency, high precision, in situ atmospheric and archived air measurements, sulfuryl fluoride has an atmospheric lifetime of 30–40 years, [8] much longer than the 5 years earlier estimated. [26]
Sulfuryl fluoride has been reported to be a greenhouse gas which is about 4000–5000 times more efficient in trapping infrared radiation (per kg) than carbon dioxide (per kg). [8] [27] [28] The amount of sulfuryl fluoride released into the atmosphere is about 2000 metric tons per year. [8] The most important loss process of sulfuryl fluoride is dissolution of atmospheric sulfuryl fluoride in the ocean followed by hydrolysis.
Sulfur dioxide or sulphur dioxide is the chemical compound with the formula SO
2. It is a colorless gas with a pungent smell that is responsible for the odor of burnt matches. It is released naturally by volcanic activity and is produced as a by-product of copper extraction and the burning of sulfur-bearing fossil fuels.
Bromomethane, commonly known as methyl bromide, is an organobromine compound with formula CH3Br. This colorless, odorless, nonflammable gas is produced both industrially and biologically. It is a recognized ozone-depleting chemical. It was used extensively as a pesticide until being phased out by most countries in the early 2000s. From a chemistry perspective, it is one of the halomethanes.
Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula PH3, classed as a pnictogen hydride. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting fish, due to the presence of substituted phosphine and diphosphane (P2H4). With traces of P2H4 present, PH3 is spontaneously flammable in air (pyrophoric), burning with a luminous flame. Phosphine is a highly toxic respiratory poison, and is immediately dangerous to life or health at 50 ppm. Phosphine has a trigonal pyramidal structure.
Fumigation is a method of pest control or the removal of harmful microorganisms by completely filling an area with gaseous pesticides, or fumigants, to suffocate or poison the pests within. It is used to control pests in buildings, soil, grain, and produce. Fumigation is also used during the processing of goods for import or export to prevent the transfer of exotic organisms.
Hydrogen bromide is the inorganic compound with the formula HBr. It is a hydrogen halide consisting of hydrogen and bromine. A colorless gas, it dissolves in water, forming hydrobromic acid, which is saturated at 68.85% HBr by weight at room temperature. Aqueous solutions that are 47.6% HBr by mass form a constant-boiling azeotrope mixture that boils at 124.3 °C (255.7 °F). Boiling less concentrated solutions releases H2O until the constant-boiling mixture composition is reached.
Thionyl chloride is an inorganic compound with the chemical formula SOCl2. It is a moderately volatile, colourless liquid with an unpleasant acrid odour. Thionyl chloride is primarily used as a chlorinating reagent, with approximately 45,000 tonnes per year being produced during the early 1990s, but is occasionally also used as a solvent. It is toxic, reacts with water, and is also listed under the Chemical Weapons Convention as it may be used for the production of chemical weapons.
Oxygen difluoride is a chemical compound with the formula OF2. As predicted by VSEPR theory, the molecule adopts a bent molecular geometry. It is a strong oxidizer and has attracted attention in rocketry for this reason. With a boiling point of −144.75 °C, OF2 is the most volatile (isolable) triatomic compound. The compound is one of many known oxygen fluorides.
Chloropicrin, also known as PS and nitrochloroform, is a chemical compound currently used as a broad-spectrum antimicrobial, fungicide, herbicide, insecticide, and nematicide. It was used as a poison gas in World War I and the Russian military has been accused of using it in the Russo-Ukrainian War. Its chemical structural formula is Cl3C−NO2.
Thionyl fluoride is the inorganic compound with the formula SOF2. 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 Cs 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.
Sulfuryl chloride is an inorganic compound with the formula SO2Cl2. At room temperature, it is a colorless liquid with a pungent odor. Sulfuryl chloride is not found in nature, as can be inferred from its rapid hydrolysis.
An inorganic nonaqueous solvent is a solvent other than water, that is not an organic compound. These solvents are used in chemical research and industry for reactions that cannot occur in aqueous solutions or require a special environment. Inorganic nonaqueous solvents can be classified into two groups, protic solvents and aprotic solvents. Early studies on inorganic nonaqueous solvents evaluated ammonia, hydrogen fluoride, sulfuric acid, as well as more specialized solvents, hydrazine, and selenium oxychloride.
Chromyl chloride is an inorganic compound with the formula CrO2Cl2. It is a reddish brown compound that is a volatile liquid at room temperature, which is unusual for transition metal compounds. It is the dichloride of chromic acid.
Sulfur tetrafluoride is a chemical compound with the formula SF4. It is a colorless corrosive gas that releases dangerous hydrogen fluoride gas upon exposure to water or moisture. Sulfur tetrafluoride is a useful reagent for the preparation of organofluorine compounds, some of which are important in the pharmaceutical and specialty chemical industries.
Sulfuryl chloride fluoride is a chemical compound with the formula SO2ClF. It is a colorless, easily condensed gas. It is a tetrahedral molecule.
Fluorosulfonate, in organic chemistry, is a functional group that has the chemical formula F-SO2-R, and typically is a very good leaving group. In organic chemistry, fluorosulfonate is different than fluorosulfate. In fluorosulfonates, sulfur atom is directly bonded to a non-oxygen atom such as carbon. In inorganic chemistry, fluorosulfonate is another term for fluorosulfate, the anion F-SO2-O−, the conjugate base of fluorosulfonic acid. They form a series of salts with metal and organic cations called fluorosulfates.
Thionyl tetrafluoride, also known as sulfur tetrafluoride oxide, is an inorganic compound with the formula SOF4. It is a colorless gas.
Thiophosphoryl fluoride is an inorganic molecular gas with formula PSF3 containing phosphorus, sulfur and fluorine. It spontaneously ignites in air and burns with a cool flame. The discoverers were able to have flames around their hands without discomfort, and called it "probably one of the coldest flames known". The gas was discovered in 1888.
In organic chemistry, sulfamoyl fluoride is an organic compound having the chemical formula F−SO2−N(−R1)−R2. Its derivatives are called sulfamoyl fluorides.
Fluorosulfite is an ion with the formula SO2F−. The term is also used for compounds or salts containing this group. Fluorosulfite was discovered in 1953 by F Seel and H Meier.
Thiothionyl fluoride is a chemical compound of fluorine and sulfur, with the chemical formula S=SF2. It is an isomer of disulfur difluoride (difluorodisulfane) F−S−S−F.
Sulfuryl fluoride, a gas fumigant, was the pesticide used to fumigate, sources told CNN.