Hexafluoro-2-propanol
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General |
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| Name | Hexafluoro-2-propanol |
| Chemical formula | C3H2F6O |
| Appearance | Colorless liquid |
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Physical |
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| Molecular weight | 168.04 amu |
| Melting point | 269 K (-4 °C) |
| Boiling point | 332 K (59 °C) |
| Density | 1.60 ×103 kg/m3 (liquid) |
| Solubility | Soluble in water |
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Thermochemistry |
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| ΔfH0gas | ? kJ/mol |
| ΔfH0liquid | ? kJ/mol |
| ΔfH0solid | ? kJ/mol |
| S0gas, 1 bar | ? J/mol·K |
| S0liquid, 1 bar | ? J/mol·K |
| S0solid | ? J/mol·K |
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Safety | |
| Ingestion | Causes burns, nausea and vomiting with possible headache. |
| Inhalation | In case of overexposure may result in spasm, inflammation and edema of larynx and bronchi, pulmonary edema and chemical pneumonitis. |
| Skin | May cause immediate burns or ulceration. |
| Eyes | Causes burns and may cause corneal and conjunctival ulceration or blindness. |
| More info | Oxford University Chemical Safety Archive |
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SI units were used where possible. Unless otherwise stated, standard conditions were used. Disclaimer and references </font> | |
Table of contents |
Production
The first step in the synthesis of hexafluoro-2-propanol is oxidation of hexafluoropropylene to yeld an impure mixture consisting of hexafluoro-2-propanone and residual hexafluoropropylene. This can be done by direct oxidation of hexafluoropropylene using aluminum oxide. The mixture of products thus obtained has to be subsequently reduced in order to hydrogenate hexafluoro-2-propanone to hexafluoro-2-propanol: this is usually achieved by using strong hydrogenating agents such as sodium borohydride in a methanol solution or lithium aluminum hydride or sodium hydride in presence of a reaction promoting solvent such as diethyl ether, methanol, isopropyl alcohol, or tetrahydrofuran. Alternatively catalysts such as Raney nickel or platinum on barium sulfate or palladium on barium sulfate can be employed succesfully for direct hydrogenation of hexafluoro-2-propanone. After reduction hexafluoro-2-propanol can be readily separated from residual amounts of hexafluoro-2-propanone and hexafluoropropylene since it has a much higher boiling point than hexafluoro-2-propanone and hexafluoropropilene will outgas easily at about room temperature.
As an alternative hexafluoro-2-propanone mixed with hydrogen fluoride can also be obtained starting from hexachloroacetone.
Uses
Hexafluoro-2-propanol is used as a solvent in organic chemistry due to its properties which make it especially useful to solubilize a wide range of polymers, including those that are not soluble in the most common organic solvents: such polymers include polyamides, polyacrilonitriles, polyacetals, polyesters (e.g. polyglycolide) and polyketones. It has also found use in biochemistry to solubilize peptides. Industrially hexafluoro-2-propanol is used as an intermediate for pharmaceuticals (anesthetics) and agrochemicals or as a solvent and cleaner in electronics.
Safety
Hexafluoro-2-propanol is a corrosive chemical and is therefore extremely destructive to tissues of the mucous membranes, upper respiratory tract, skin and eyes: as with any corrosive care should be taken to avoid contact using protective equipment as needed. It is not considered carcinogenic, but the effects of a chronic exposure are unknown.
References
- United States Patent 4,314,087: "Methods of synthesizing hexafluoroisopropanol from impure mixtures and synthesis of a fluoromethyl ether therefrom".
Categories: Organofluorides