Chlorodifluoromethane
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| Names | |||
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Preferred IUPAC name
Chloro(difluoro)methane
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| Other names
Chlorodifluoromethane
Difluoromonochloromethane Monochlorodifluoromethane HCFC-22 R-22 Genetron 22 Freon 22 Arcton 4 Arcton 22 UN 1018 Difluorochloromethane Fluorocarbon-22 Refrigerant 22 |
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| Identifiers | |||
75-45-6 
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| 3D model (Jmol) | Interactive image | ||
| ChEMBL |
ChEMBL116155
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| ChemSpider |
6132
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| ECHA InfoCard | 100.000.793 | ||
| EC Number | 200-871-9 | ||
| KEGG |
C19361 
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| PubChem | 6372 | ||
| RTECS number | PA6390000 | ||
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| Properties | |||
| CHClF2 | |||
| Molar mass | 86.47 g/mol | ||
| Appearance | Colorless gas | ||
| Odor | sweetish | ||
| Density | 3.66 kg/m3 at 15 °C, gas | ||
| Melting point | −175.42 °C (−283.76 °F; 97.73 K) | ||
| Boiling point | −40.7 °C (−41.3 °F; 232.5 K) | ||
| 0.7799 vol/vol at 25 °C; 3.628 g/L | |||
| log P | 1.08 | ||
| Vapor pressure | 908 kPa at 20 °C | ||
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Henry's law
constant (kH) |
0.033 mol.kg−1.bar−1 | ||
| -38.6·10−6 cm3/mol | |||
| Structure | |||
| Tetrahedral | |||
| Hazards | |||
| Main hazards | Dangerous for the environment (N), Central nervous system depressant, Carc. Cat. 3 | ||
| R-phrases | R59 | ||
| S-phrases | S23 S24 S25 S59 | ||
| NFPA 704 | |||
| Flash point | nonflammable | ||
| 632 °C (1,170 °F; 905 K) | |||
| US health exposure limits (NIOSH): | |||
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PEL (Permissible)
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none | ||
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REL (Recommended)
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TWA 1000 ppm (3500 mg/m3) ST 1250 ppm (4375 mg/m3) | ||
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IDLH (Immediate danger)
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N.D. | ||
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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 (what is ?) |
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| Infobox references | |||
Chlorodifluoromethane or difluoromonochloromethane is a hydrochlorofluorocarbon (HCFC). This colorless gas is better known as HCFC-22, or R-22. It is commonly used as a propellant and refrigerant. These applications are being phased out in developed countries due to the compound's ozone depletion potential (ODP) and high global warming potential (GWP), although global use of R-22 continues to increase because of high demand in developing countries. R-22 is a versatile intermediate in industrial organofluorine chemistry, e.g. as a precursor to tetrafluoroethylene. R-22 cylinders are colored light green.
Worldwide production of R-22 in 2008 was about 800 Gg per year, up from about 450 Gg per year in 1998, with most production in developing countries. R-22 use is increasing in developing countries, largely for air conditioning applications. Air conditioning sales are growing 20% annually in India and China.
R-22 is prepared from chloroform:
An important application of R-22 is as a precursor to tetrafluoroethylene. This conversion involves pyrolysis to give difluorocarbene, which dimerizes:
The compound also yields difluorocarbene upon treatment with strong base and is used in the laboratory as a source of this reactive intermediate.
The pyrolysis of R-22 in the presence of chlorofluoromethane gives hexafluorobenzene.
R-22 is often used as an alternative to the highly ozone-depleting CFC-11 and CFC-12, because of its relatively low ozone depletion potential of 0.055, among the lowest for chlorine-containing haloalkanes. However, even this lower ozone depletion potential is no longer considered acceptable.
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