Trichlorofluoromethane

Last updated
Trichlorofluoromethane
Trichlorofluoromethane-2D.svg
Trichlorofluoromethane-3D-vdW.png
Names
Preferred IUPAC name
Trichloro(fluoro)methane
Other names
Trichlorofluoromethane
Fluorotrichloromethane
Fluorochloroform
Freon 11
CFC 11
R 11
Arcton 9
Freon 11A
Freon 11B
Freon HE
Freon MF
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.000.812 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 200-892-3
PubChem CID
RTECS number
  • PB6125000
UNII
  • InChI=1S/CCl3F/c2-1(3,4)5 Yes check.svgY
    Key: CYRMSUTZVYGINF-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/CCl3F/c2-1(3,4)5
  • C(F)(Cl)(Cl)Cl
  • ClC(Cl)(Cl)F
Properties
CCl3F
Molar mass 137.36 g·mol−1
AppearanceColorless liquid/gas
Odor nearly odorless [1]
Density 1.494 g/cm3
Melting point −110.48 °C (−166.86 °F; 162.67 K)
Boiling point 23.77 °C (74.79 °F; 296.92 K)
1.1 g/L (at 20 °C)
log P 2.53
Vapor pressure 89 kPa at 20 °C
131 kPa at 30 °C
Thermal conductivity 0.0079 W m−1 K−1 (gas at 300 K, ignoring pressure dependence) [2] [ verification needed ]
Hazards
GHS labelling: [3]
GHS-pictogram-exclam.svg
Warning
H420
P502
Flash point Non-flammable
Lethal dose or concentration (LD, LC):
26,200 ppm (rat, 4 hr)
100,000 ppm (rat, 20 min)
100,000 ppm (rat, 2 hr) [4]
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 1000 ppm (5600 mg/m3) [1]
REL (Recommended)
C 1000 ppm (5600 mg/m3) [1]
IDLH (Immediate danger)
2000 ppm [1]
Safety data sheet (SDS) ICSC 0047
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Trichlorofluoromethane, also called freon-11, CFC-11, or R-11, is a chlorofluorocarbon (CFC). It is a colorless, faintly ethereal, and sweetish-smelling liquid that boils around room temperature. [5] CFC-11 is a Class 1 ozone-depleting substance which damages Earth's protective stratospheric ozone layer. [6]

Contents

Historical use

Trichlorofluoromethane was first widely used as a refrigerant. Because of its high boiling point compared to most refrigerants, it can be used in systems with a low operating pressure, making the mechanical design of such systems less demanding than that of higher-pressure refrigerants R-12 or R-22.

Trichlorofluoromethane is used as a reference compound for fluorine-19 NMR studies.

Trichlorofluoromethane was formerly used in the drinking bird novelty, largely because it has a boiling point of 23.77 °C (74.79 °F). The replacement, dichloromethane, boiling point 39.6 °C (103.3 °F), requires a higher ambient temperature to work.

Prior to the knowledge of the ozone depletion potential of chlorine in refrigerants and other possible harmful effects on the environment, trichlorofluoromethane was sometimes used as a cleaning/rinsing agent for low-pressure systems. [7]

Production

Trichlorofluoromethane can be obtained by reacting carbon tetrachloride with hydrogen fluoride at 435 °C and 70 atm, producing a mixture of trichlorofluoromethane, tetrafluoromethane and dichlorodifluoromethane in a ratio of 77:18:5. The reaction can also be carried out in the presence of antimony(III) chloride or antimony(V) chloride: [8]

Trichlorofluoromethane is also formed as one of the byproducts when graphite reacts with chlorine and hydrogen fluoride at 500 °C. [8]

Sodium hexafluorosilicate under pressure at 270 °C, titanium(IV) fluoride, chlorine trifluoride, cobalt(III) fluoride, iodine pentafluoride, and bromine trifluoride are also suitable fluorinating agents for carbon tetrachloride. [8] [9]


Trichlorofluoromethane was included in the production moratorium in the Montreal Protocol of 1987. It is assigned an ozone depletion potential of 1.0, and U.S. production was ended on January 1, 1996. [6]

Regulatory challenges

In 2018, the atmospheric concentration of CFC-11 was noted by researchers to be declining more slowly than expected, [10] [11] and it subsequently emerged that it remains in widespread use as a blowing agent for polyurethane foam insulation in the construction industry of China. [12] In 2021, researchers announced that emissions declined by 20,000 U.S. tons from 2018 to 2019, which mostly reversed the previous spike in emissions. [13] In 2022, the European Commission announced an updated regulation that mandates the recovery and prevention of emissions of CFC-11 blowing agents from foam insulation in demolition waste, which is still emitted at significant scale. [14]

Dangers

R11, like most chlorofluorocarbons, forms phosgene gas when exposed to a naked flame. [15]

See also

Related Research Articles

<span class="mw-page-title-main">Bromine</span> Chemical element, symbol Br and atomic number 35

Bromine is a chemical element; it has symbol Br and atomic number 35. It is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are intermediate between those of chlorine and iodine. Isolated independently by two chemists, Carl Jacob Löwig and Antoine Jérôme Balard, its name was derived from the Ancient Greek βρῶμος (bromos) meaning "stench", referring to its sharp and pungent smell.

<span class="mw-page-title-main">Montreal Protocol</span> 1987 treaty to protect the ozone layer

The Montreal Protocol is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion. It was agreed on 16 September 1987, and entered into force on 1 January 1989. Since then, it has undergone nine revisions, in 1990 (London), 1991 (Nairobi), 1992 (Copenhagen), 1993 (Bangkok), 1995 (Vienna), 1997 (Montreal), 1998 (Australia), 1999 (Beijing) and 2016 (Kigali) As a result of the international agreement, the ozone hole in Antarctica is slowly recovering. Climate projections indicate that the ozone layer will return to 1980 levels between 2040 and 2066. Due to its widespread adoption and implementation, it has been hailed as an example of successful international co-operation. Former UN Secretary-General Kofi Annan stated that "perhaps the single most successful international agreement to date has been the Montreal Protocol". In comparison, effective burden-sharing and solution proposals mitigating regional conflicts of interest have been among the success factors for the ozone depletion challenge, where global regulation based on the Kyoto Protocol has failed to do so. In this case of the ozone depletion challenge, there was global regulation already being installed before a scientific consensus was established. Also, overall public opinion was convinced of possible imminent risks.

<span class="mw-page-title-main">Phosgene</span> Toxic gaseous compound (COCl2)

Phosgene is an organic chemical compound with the formula COCl2. It is a toxic, colorless gas; in low concentrations, its musty odor resembles that of freshly cut hay or grass. It can be thought of chemically as the double acyl chloride analog of carbonic acid, or structurally as formaldehyde with the hydrogen atoms replaced by chlorine atoms. Phosgene is a valued and important industrial building block, especially for the production of precursors of polyurethanes and polycarbonate plastics.

<span class="mw-page-title-main">Chlorofluorocarbon</span> Class of organic compounds commonly used as refrigerants

Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are fully or partly halogenated hydrocarbons that contain carbon (C), hydrogen (H), chlorine (Cl), and fluorine (F), produced as volatile derivatives of methane, ethane, and propane.

<span class="mw-page-title-main">Carbon tetrachloride</span> Chemical compound

Carbon tetrachloride, also known by many other names (such as carbon tet for short and tetrachloromethane, also recognised by the IUPAC) is a chemical compound with the chemical formula CCl4. It is a non-flammable, dense, colourless liquid with a "sweet" chloroform-like odour that can be detected at low levels. It was formerly widely used in fire extinguishers, as a precursor to refrigerants and as a cleaning agent, but has since been phased out because of environmental and safety concerns. Exposure to high concentrations of carbon tetrachloride can affect the central nervous system and degenerate the liver and kidneys. Prolonged exposure can be fatal.

<span class="mw-page-title-main">Dichloromethane</span> Chemical compound

Dichloromethane is an organochlorine compound with the formula CH2Cl2. This colorless, volatile liquid with a chloroform-like, sweet odor is widely used as a solvent. Although it is not miscible with water, it is slightly polar, and miscible with many organic solvents.

Chloromethane, also called methyl chloride, Refrigerant-40, R-40 or HCC 40, is an organic compound with the chemical formula CH3Cl. One of the haloalkanes, it is a colorless, sweet-smelling, flammable gas. Methyl chloride is a crucial reagent in industrial chemistry, although it is rarely present in consumer products, and was formerly utilized as a refrigerant. Most chloromethane is biogenic.

<span class="mw-page-title-main">Halomethane</span> Halogen compounds derived from methane

Halomethane compounds are derivatives of methane with one or more of the hydrogen atoms replaced with halogen atoms. Halomethanes are both naturally occurring, especially in marine environments, and human-made, most notably as refrigerants, solvents, propellants, and fumigants. Many, including the chlorofluorocarbons, have attracted wide attention because they become active when exposed to ultraviolet light found at high altitudes and destroy the Earth's protective ozone layer.

Dichlorodifluoromethane (R-12) is a colorless gas usually sold under the brand name Freon-12, and a chlorofluorocarbon halomethane (CFC) used as a refrigerant and aerosol spray propellant. In compliance with the Montreal Protocol, its manufacture was banned in developed countries in 1996, and in developing countries in 2010 out of concerns about its damaging effect on the ozone layer. Its only allowed usage is as a fire retardant in submarines and aircraft. It is soluble in many organic solvents. R-12 cylinders are colored white.

Chlorodifluoromethane or difluoromonochloromethane is a hydrochlorofluorocarbon (HCFC). This colorless gas is better known as HCFC-22, or R-22, or CHClF
2
. It was commonly used as a propellant and refrigerant. These applications were phased out under the Montreal Protocol in developed countries in 2020 due to the compound's ozone depletion potential (ODP) and high global warming potential (GWP), and in developing countries this process will be completed by 2030. R-22 is a versatile intermediate in industrial organofluorine chemistry, e.g. as a precursor to tetrafluoroethylene.

<span class="mw-page-title-main">Nitrogen trifluoride</span> Chemical compound

Nitrogen trifluoride is an inorganic, colorless, non-flammable, toxic gas with a slightly musty odor. It finds increasing use within the manufacturing of flat-panel displays, photovoltaics, LEDs and other microelectronics. Nitrogen trifluoride is also an extremely strong and long-lived greenhouse gas. Its atmospheric burden exceeded 2 parts per trillion during 2019 and has doubled every five years since the late 20th century.

1,2-Dichlorotetrafluoroethane, or R-114, also known as cryofluorane (INN), is a chlorofluorocarbon (CFC) with the molecular formula ClF2CCF2Cl. Its primary use has been as a refrigerant. It is a non-flammable gas with a sweetish, chloroform-like odor with the critical point occurring at 145.6 °C and 3.26 MPa. When pressurized or cooled, it is a colorless liquid. It is listed on the Intergovernmental Panel on Climate Change's list of ozone depleting chemicals, and is classified as a Montreal Protocol Class I, group 1 ozone depleting substance.

Chlorotrifluoromethane, R-13, CFC-13, or Freon 13, is a non-flammable, non-corrosive, nontoxic chlorofluorocarbon (CFC) and also a mixed halomethane. It is a man-made substance used primarily as a refrigerant. When released into the environment, CFC-13 has a high ozone depletion potential, and long atmospheric lifetime. Only a few other greenhouse gases surpass CFC-13 in global warming potential (GWP). The IPCC AR5 reported that CFC-13's atmospheric lifetime was 640 years.

Organofluorine chemistry describes the chemistry of organofluorine compounds, organic compounds that contain a carbon–fluorine bond. Organofluorine compounds find diverse applications ranging from oil and water repellents to pharmaceuticals, refrigerants, and reagents in catalysis. In addition to these applications, some organofluorine compounds are pollutants because of their contributions to ozone depletion, global warming, bioaccumulation, and toxicity. The area of organofluorine chemistry often requires special techniques associated with the handling of fluorinating agents.

<span class="mw-page-title-main">Dichlorofluoromethane</span> Chemical compound

Dichlorofluoromethane or Freon 21 or R 21 is a halomethane or hydrochlorofluorocarbon with the formula CHCl2F. It is a colorless and odorless gas. It is produced by fluorination of chloroform using a catalyst such as antimony trifluoride:

<span class="mw-page-title-main">Chloropentafluoroethane</span> Chemical compound

Chloropentafluoroethane is a chlorofluorocarbon (CFC) once used as a refrigerant and also known as R-115 and CFC-115. Its production and consumption has been banned since 1 January 1996 under the Montreal Protocol because of its high ozone depletion potential and very long lifetime when released into the environment. CFC-115 is also a potent greenhouse gas.

1,1,2-Trichloro-1,2,2-trifluoroethane, also called trichlorotrifluoroethane or CFC-113, is a chlorofluorocarbon. It has the formula Cl2FC−CClF2. This colorless, volatile liquid is a versatile solvent.

<span class="mw-page-title-main">1,1-Dichloro-1-fluoroethane</span> Chemical compound

1,1-Dichloro-1-fluoroethane is a haloalkane with the formula C
2
H
3
Cl
2
F
. It is one of the three isomers of dichlorofluoroethane. It belongs to the hydrochlorofluorocarbon (HCFC) family of man-made compounds that contribute significantly to both ozone depletion and global warming when released into the environment.

<span class="mw-page-title-main">1-Chloro-1,1-difluoroethane</span> Chemical compound

1-Chloro-1,1-difluoroethane (HCFC-142b) is a haloalkane with the chemical formula CH3CClF2. It belongs to the hydrochlorofluorocarbon (HCFC) family of man-made compounds that contribute significantly to both ozone depletion and global warming when released into the environment. It is primarily used as a refrigerant where it is also known as R-142b and by trade names including Freon-142b.

<span class="mw-page-title-main">1,1-Dichlorotetrafluoroethane</span> Chemical compound

1,1-Dichlorotetrafluoroethane is a chlorofluorocarbon also known as CFC-114a or R114a by American Society of Heating, Refrigerating, and Air Conditioning Engineers. It has two chlorine atoms on one carbon atom and none on the other. It is one of two isomers of dichlorotetrafluoroethane, the other being 1,2-dichlorotetrafluoroethane, also known as CFC-114.

References

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