1,2-difluoroethane
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IUPAC name
1,2-difluoroethane
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| Identifiers | |
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3D model (Jmol)
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| ChemSpider | |
| EC Number | 200-866-1 |
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PubChem CID
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| Properties | |
| CFH 2CFH 2 |
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| Molar mass | 66.05 g·mol−1 |
| Appearance | colourless liquid |
| Density | 0.913 |
| Melting point | −104 °C; −155 °F; 169 K |
| Boiling point | 30.7 °C (87.3 °F; 303.8 K) |
| 2.31 g/L | |
| Solubility | ether, benzene, chloroform |
| log P | 1.21 |
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Refractive index (nD)
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1.28 (liquid) |
| Structure | |
| monoclinic | |
| C2/c | |
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a = 7.775, b = 4.4973, c = 9.024
α = 90°, β = 101.73°, γ = 90°
density 1.420
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Lattice volume (V)
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308.9 |
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Formula units (Z)
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4 |
| Structure | |
| Orthorhombic | |
| P212121 | |
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a = 8.047, b = 4.5086, c = 8.279
α = 90°, β = 101.73°, γ = 90°
density 1.461
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Lattice volume (V)
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300.4 |
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Formula units (Z)
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4 |
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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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| Infobox references | |
1,2-Difluoroethane is a saturated hydrofluorocarbon containing an atom of fluorine attached to each of two carbons atoms. The formula can be written CH2FCH2F. It is an isomer of 1,1-Difluoroethane. It has a HFC name of HFC-152 with no letter suffix. When cooled to cryogenic temperatures it can have different conformers, gauche and trans. In the liquid form these are about equally abundant and easily interconvert. As a gas it is mostly the gauche form.
In the HFC-152 designation, 2 means two fluorine atoms, 5 means 5-1 or four hydrogen atoms, and 1 means 1+1 or two carbon atoms.
Ethylene reacts explosively with fluorine yielding a mixture of 1,2-difluoroethane and vinyl fluoride. With solid fluorine it will react when triggered by near-infrared radiation.
Critical temperature is 107.5 °C.
If a C-H bond is over excited with too much vibration, the intramolecular vibrational relaxation takes 490 picoseconds.
The F-C-C-F dihedral angle is about 72°.
CH2FCH2F reacts with chlorine when treated with light. Two products are formed CH2FCCl2F and CHClFCHClF. The proportions of each depends on the solvent.
When 1,2-difluoroethane is released to the environment, it will end up in the atmosphere. Here it is degraded by reaction with hydroxyl radicals and oxygen.
When catalysed by chlorine atoms and oxidised by nitrogen oxides the end product is HCOF which can decompose further to HF and CO.
The halflife in air is between 140 and 180 days.
When inhaled by rats, 1,2-difluoroethane is converted to fluoroacetate using and then to fluorocitrate both toxic. 100 parts per million in the atmosphere was sufficient to poison rats in 30 minutes and to kill them in four hours. 1,2-Difluoroethane is likely to be similarly toxic to humans.
1,2-Difluoroethane is a greenhouse gas when released to the atmosphere. It has a warming equivalent to 140 times that of carbon dioxide. As such it may be controlled by government regulation. The Australian government classifies 1,2-difluoroethane as an exotic synthetic greenhouse gas.
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