1,1-Dichlorotetrafluoroethane

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1,1-Dichlorotetrafluoroethane
1,1-Dichlor-1,2,2,2-tetrafluorethane.svg
1,1-Dichloro-1,2,2,2-tetrafluoroethane.png
Names
IUPAC name
1,1-dichloro-1,2,2,2-tetrafluoroethane
Other names
R114a; CFC-114a
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.006.159 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 206-774-8
PubChem CID
UNII
  • InChI=1S/C2Cl2F4/c3-1(4,5)2(6,7)8
    Key: BAMUEXIPKSRTBS-UHFFFAOYSA-N
  • C(C(F)(Cl)Cl)(F)(F)F
Properties
C2Cl2F4
Molar mass 170.92 g·mol−1
Density 1.455 g/cu cm (as a liquid under pressure)
Melting point −56.6 °C (−69.9 °F; 216.6 K)
Boiling point 3.4 °C (38.1 °F; 276.5 K)
137 mg/L
Solubility benzene, diethyl ether, ethanol
log P 2.78
Vapor pressure 1640 mm Hg
1.3092 at 0 °C
Hazards
GHS labelling: [1]
GHS-pictogram-bottle.svg GHS-pictogram-exclam.svg GHS-pictogram-pollu.svg
Danger
H335, H336, H370, H420
P260, P261, P264, P270, P271, P304+P340, P308+P316, P319, P321, P403+P233, P405, P501, P502
Related compounds
Related compounds
 CFC-114
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

1,1-Dichlorotetrafluoroethane is a chlorofluorocarbon also known as CFC-114a or R114a by American Society of Heating, Refrigerating, and Air Conditioning Engineers. [2] 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.

Contents

Formation

1,1-Dichlorotetrafluoroethane can be made free from other isomers by reacting trichlorotrifluoroethane (CFC-113 or CFC-113a) with antimony pentachloride. [3] Trichlorotrifluoroethane can also be reacted with sulfur tetrafluoride or dichlorodifluoromethane with aluminium fluoride catalyst to yield 1,1-dichlorotetrafluoroethane. The use of aluminium in the catalyst favours the asymmetric molecules. [4]

It can also be made in a reaction of tetrachloroethylene with hydrogen fluoride and chlorine, but this results in a mixture. [3]

Fluorinating 1,2-dichlorodifluoroethylene with fluorine produces a small amount of 1,1-dichlorotetrafluoroethane, but mostly tetrachlorotetrafluorobutene and some other chloroflurocarbons, so is not a good way. [5]

Properties

1,1-Dichlorotetrafluoroethane has a close boiling point (3.6°C) to the isomer 1,2-dichlorotetrafluoroethane (3.8°C), and so is difficult to separate by distillation. [6] Also in a gas chromatograph, it is hard to distinguish from the symmetric 1,2 isomer. [6]

Critical properties include critical temperature 145.7°C, critical pressure 4.92 Mpa and critical density of 0.82 g/ml. [7]

1,1-Dichlorotetrafluoroethane does not ignite in air. [7]

Reactions

1,1-Dichlorotetrafluoroethane reacts with hydrogen when heated at 300 to 600°C with a palladium catalyst in a hydrodechlorination. The main reaction product is 1,1,1,2-tetrafluoroethane, but also 1-chloro-1,2,2,2-tetrafluoroethane (CF3CHClF) and 1,1,1-trifluoroethane are formed. [8]

1,1-Dichlorotetrafluoroethane reacts with alkali metals, alkaline earths and aluminium. [7]

When heated with hydrogen over a nickel catalyst, 1,1-dichlorotetrafluoroethane is dechlorinated with replacement by hydrogen to yield a mixture of CF3CHClF and the dimer CF3CClFCClFCF3. [9]

Use

CFC-114a was used in aerosol propellants, blowing agents, and in polyolefin foams. There was also use in refrigerants. Production was banned in by the Montreal Protocol. [10]

CFC-114a is a possible intermediate in the production of HFC-134a [10] which can be produced by hydrogenation. [11]

Atmosphere

Mixing ratio of CFC-114a in air (red). Also CFC-114 in black Laube-CFC-114level.png
Mixing ratio of CFC-114a in air (red). Also CFC-114 in black

The ozone depletion potential of 1,1-dichlorotetrafluoroethane is 0.72. [12] The estimated lifetime in the atmosphere is about 100 years. [12] The radiative efficiency is 0.28 Wm−2ppb−1. [12] Global warming potential in 20 years is 6750. [12] The atmospheric concentration of CFC-114a is not usually measured separately from CFC-114 due to difficulties in distinguishing them apart. [12]

In 1978 atmospheric levels of CFC-114a were 0.35 ppt. By 2020 the level was up to 1.13 ppt. [13] CFC-114a appears to be emitted into the atmosphere is South East Asia. [10]

The atmospheric natural destruction of CFC-114a is by reaction with atomic oxygen, or breakup by ultraviolet light. [10] As of 2014 about 250 tons per year of CFC-114a were being put into the atmosphere. [10]

Related Research Articles

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

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">Haloalkane</span> Group of chemical compounds derived from alkanes containing one or more halogens

The haloalkanes are alkanes containing one or more halogen substituents. They are a subset of the general class of halocarbons, although the distinction is not often made. Haloalkanes are widely used commercially. They are used as flame retardants, fire extinguishants, refrigerants, propellants, solvents, and pharmaceuticals. Subsequent to the widespread use in commerce, many halocarbons have also been shown to be serious pollutants and toxins. For example, the chlorofluorocarbons have been shown to lead to ozone depletion. Methyl bromide is a controversial fumigant. Only haloalkanes that contain chlorine, bromine, and iodine are a threat to the ozone layer, but fluorinated volatile haloalkanes in theory may have activity as greenhouse gases. Methyl iodide, a naturally occurring substance, however, does not have ozone-depleting properties and the United States Environmental Protection Agency has designated the compound a non-ozone layer depleter. For more information, see Halomethane. Haloalkane or alkyl halides are the compounds which have the general formula "RX" where R is an alkyl or substituted alkyl group and X is a halogen.

Freon is a registered trademark of the Chemours Company and generic descriptor for a number of halocarbon products. They are stable, nonflammable, low toxicity gases or liquids which have generally been used as refrigerants and as aerosol propellants. These include chlorofluorocarbons and hydrofluorocarbons, both of which cause ozone depletion and contribute to global warming. 'Freon' is the brand name for the refrigerants R-12, R-13B1, R-22, R-410A, R-502, and R-503 manufactured by The Chemours Company, and so is not used to label all refrigerants of this type. They emit a strong smell similar to acetone. Freon has been found to cause damage to human health when inhaled in large amounts. Studies have been conducted in the pursuit to find beneficial reuses for gases under the Freon umbrella as an alternative to disposal of the gas.

<span class="mw-page-title-main">Hydrofluorocarbon</span> Synthetic organic compounds

Hydrofluorocarbons (HFCs) are synthetic organic compounds that contain fluorine and hydrogen atoms, and are the most common type of organofluorine compounds. Most are gases at room temperature and pressure. They are frequently used in air conditioning and as refrigerants; R-134a (1,1,1,2-tetrafluoroethane) is one of the most commonly used HFC refrigerants. In order to aid the recovery of the stratospheric ozone layer, HFCs were adopted to replace the more potent chlorofluorocarbons (CFCs), which were phased out from use by the Montreal Protocol, and hydrochlorofluorocarbons (HCFCs) which are presently being phased out. HFCs replaced older chlorofluorocarbons such as R-12 and hydrochlorofluorocarbons such as R-21. HFCs are also used in insulating foams, aerosol propellants, as solvents and for fire protection.

Halocarbon compounds are chemical compounds in which one or more carbon atoms are linked by covalent bonds with one or more halogen atoms resulting in the formation of organofluorine compounds, organochlorine compounds, organobromine compounds, and organoiodine compounds. Chlorine halocarbons are the most common and are called organochlorides.

Difluoromethane, also called difluoromethylene, HFC-32Methylene Fluoride or R-32, is an organic compound of the dihalogenoalkane variety. It has the formula of CH2F2. It is a colorless gas in the ambient atmosphere and is slightly soluble in water, with a high thermal stability. Due to the low melting and boiling point, (-136.0 °C and -51.6 °C respectively) contact with this compound may result in frostbite. In the United States, the Clean Air Act Section 111 on Volatile Organic Compounds (VOC) has listed difluoromethane as an exception (since 1997) from the definition of VOC due to its low production of tropospheric ozone. Difluoromethane is commonly used in endothermic processes such as refrigeration or air conditioning.

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.

1,1,1,2-Tetrafluoroethane (also known as norflurane (INN), R-134a, Klea 134a, Freon 134a, Forane 134a, Genetron 134a, Green Gas, Florasol 134a, Suva 134a, HFA-134a, or HFC-134a) is a hydrofluorocarbon (HFC) and haloalkane refrigerant with thermodynamic properties similar to R-12 (dichlorodifluoromethane) but with insignificant ozone depletion potential and a lower 100-year global warming potential (1,430, compared to R-12's GWP of 10,900). It has the formula CF3CH2F and a boiling point of −26.3 °C (−15.34 °F) at atmospheric pressure. R-134a cylinders are colored light blue. A phaseout and transition to HFO-1234yf and other refrigerants, with GWPs similar to CO2, began in 2012 within the automotive market.

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. CFC-11 is a Class 1 ozone-depleting substance which damages Earth's protective stratospheric ozone layer.

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

Tetrafluoromethane, also known as carbon tetrafluoride or R-14, is the simplest perfluorocarbon (CF4). As its IUPAC name indicates, tetrafluoromethane is the perfluorinated counterpart to the hydrocarbon methane. It can also be classified as a haloalkane or halomethane. Tetrafluoromethane is a useful refrigerant but also a potent greenhouse gas. It has a very high bond strength due to the nature of the carbon–fluorine bond.

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

Octafluorocyclobutane, or perfluorocyclobutane, C4F8, is an organofluorine compound which enjoys several niche applications. Octafluorocyclobutane is a colourless gas and shipped as a liquefied gas. It is the perfluorinated analogue of cyclobutane whereby all C–H bonds are replaced with C–F bonds.

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.

<span class="mw-page-title-main">2,2-Dichloro-1,1,1-trifluoroethane</span> Chemical compound

2,2-Dichloro-1,1,1-trifluoroethane or HCFC-123 is considered as an alternative to CFC-11 in low pressure refrigeration and HVAC systems, and should not be used in foam blowing processes or solvent applications. It is also the primary component of the Halotron I fire-extinguishing mixture.

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.

Asymmetrical trichlorotrifluoroethane, also called 1,1,1-Trichloro-2,2,2-trifluoroethane or CFC-113a is a chlorofluorocarbon (CFC). It has the formula CCl3CF3.

<span class="mw-page-title-main">1,2-Dichloro-1,1,2-trifluoroethane</span> Chemical compound

1,2-Dichloro-1,1,2-trifluoroethane is a volatile liquid chlorofluoroalkane composed of carbon, hydrogen, chlorine and fluorine, and with structural formula CClF2CHClF. It is also known as a refrigerant with the designation R-123a.

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

Tetrachloro-1,1-difluoroethane or 1,1,1,2-tetrachloro-2,2-difluoroethane, Freon 112a, R-112a, or CFC-112a is an asymmetric chlorofluorocarbon isomer of tetrachloro-1,1-difluoroethane with formula CClF2CCl3. It contains ethane substituted by four chlorine atoms and two fluorine atoms. With a boiling point of 91.5°C it is the freon with second highest boiling point.

<span class="mw-page-title-main">Tetrachloro-1,2-difluoroethane</span> Chemical compound

Tetrachloro-1,2-difluoroethane is a chlorofluorocarbon known as Freon 112, CFC-112 or R-112. It has a symmetrical structure CCl2FCCl2F and so can be called symmetrical tetrachlorodifluoroethane. "Symmetrical" may also be abbreviated to "s-" or "sym-". In contrast an asymmetrical isomer has formula CCl3CClF2.

<span class="mw-page-title-main">2-Chloro-1,1-difluoroethylene</span> Chemical compound

2-Chloro-1,1-difluoroethene (also known as R 1122, u-HCFC-1122 or HCFO-1122) is a toxic unsaturated hydrochlorofluorocarbon which can be written as CF2=CHCl. The HCFO portion of the name stands for hydrochlorofluoroolefin. Another constitutional isomer of it, 1-chloro-1,2-difluoroethylene, is known as HCFO-1122a.

References

  1. ↑ "1,1-Dichloro-1,2,2,2-tetrafluoroethane". pubchem.ncbi.nlm.nih.gov.
  2. ↑ Deiters, Ulrich K (May 1997). "Some remarks on the nomenclature of refrigerants". Fluid Phase Equilibria. 132 (1–2): 265–270. doi:10.1016/S0378-3812(96)03232-3.
  3. 1 2 Gumprecht, William Henry; Longoria, John Mark; Christoph, Frank J. (8 May 1991). "Process for manufacture of 1,1-dichlorotetrafluoroethane".
  4. ↑ Bozorgzadeh, H; Kemnitz, E; Nickkho-Amiry, M; Skapin, T; Winfield, J.M (January 2001). "Conversion of 1,1,2-trichlorotrifluoroethane to 1,1,1-trichlorotrifluoroethane and 1,1-dichlorotetrafluoroethane over aluminium-based catalysts". Journal of Fluorine Chemistry. 107 (1): 45–52. doi:10.1016/S0022-1139(00)00350-X.
  5. ↑ Haszeldine, R. N. (1952). "849. Fluoro-olefins. Part I. The synthesis of hexafluorobuta-1 : 3-diene". Journal of the Chemical Society (Resumed): 4423. doi:10.1039/JR9520004423.
  6. 1 2 Chen, Limin; Makide, Yoshihiro; Tominaga, Takeshi (1994). "Determination of 1,2-dichlorotetrafluoroethane (CFC-114) Concentration in the Atmosphere". Chemistry Letters. 23 (3): 571–574. doi:10.1246/cl.1994.571.
  7. 1 2 3 Bruno, Thomas J. (1990). Spectroscopic Library for Alternative Refrigerant Analysis. U.S. Department of Commerce, National Institute of Standards and Technology. pp. 25–27.
  8. ↑ Karpinski, Zbigniew; Early, Kintu; d'Itri, Julie L. (December 1996). "Catalytic Hydrodechlorination of 1,1-Dichlorotetrafluoroethane by Pd/Al2O3". Journal of Catalysis. 164 (2): 378–386. doi:10.1006/jcat.1996.0394.
  9. ↑ Tomioka, Satoshi; Mori, Tohru; Ueda, Wataru; Morikawa, Yutaka; Ikawa, Tsuneo (October 1991). "A Novel Hydrodechlorinative Dimerization of Chlorofluorocarbons over Supported Ni Catalysts". Chemistry Letters. 20 (10): 1825–1826. doi:10.1246/cl.1991.1825.
  10. 1 2 3 4 5 Laube, Johannes C.; Mohd Hanif, Norfazrin; Martinerie, Patricia; Gallacher, Eileen; Fraser, Paul J.; Langenfelds, Ray; Brenninkmeijer, Carl A. M.; Schwander, Jakob; Witrant, Emmanuel; Wang, Jia-Lin; Ou-Yang, Chang-Feng; Gooch, Lauren J.; Reeves, Claire E.; Sturges, William T.; Oram, David E. (9 December 2016). "Tropospheric observations of CFC-114 and CFC-114a with a focus on long-term trends and emissions". Atmospheric Chemistry and Physics. 16 (23): 15347–15358. Bibcode:2016ACP....1615347L. doi: 10.5194/acp-16-15347-2016 . S2CID   54195362.
  11. ↑ Suh, Dong Jin; Park, Tae-Jin; Lee, Byung-Gwon; Park, Kun-You (January 1996). "Synthesis of HFC-134a by isomerization and hydrogenation". Korean Journal of Chemical Engineering. 13 (1): 75–81. doi:10.1007/BF02705892. S2CID   97614597.
  12. 1 2 3 4 5 Davis, Maxine E.; Bernard, François; McGillen, Max R.; Fleming, Eric L.; Burkholder, James B. (1 July 2016). "UV and infrared absorption spectra, atmospheric lifetimes, and ozone depletion and global warming potentials for CCl<sub>2</sub>FCCl<sub>2</sub>F (CFC-112), CCl<sub>3</sub>CClF<sub>2</sub> (CFC-112a), CCl<sub>3</sub>CF<sub>3</sub> (CFC-113a), and CCl<sub>2</sub>FCF<sub>3</sub> (CFC-114a)". Atmospheric Chemistry and Physics. 16 (12): 8043–8052. Bibcode:2016ACP....16.8043D. doi: 10.5194/acp-16-8043-2016 . hdl: 1983/df193a7b-14de-427c-a539-238701f9e3b3 . S2CID   102078043.
  13. ↑ Western, Luke M.; et al. (3 April 2023). "Global increase of ozone-depleting chlorofluorocarbons from 2010 to 2020". Nature Geoscience. 16 (4): 309–313. Bibcode:2023NatGe..16..309W. doi:10.1038/s41561-023-01147-w. hdl: 1983/9e103fef-e61c-49c7-a1a3-902540ec1d7c . S2CID   257941769.
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