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Names | |
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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 |
EC Number |
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PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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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 |
Refractive index (nD) | 1.3092 at 0 °C |
Hazards | |
GHS labelling: [1] | |
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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.
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]
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]
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]
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]
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]