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Names | |||
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Preferred IUPAC name
Methoxymethane
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Other names
Dimethyl ether
R-E170 Demeon Dimethyl oxide |
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Identifiers | |||
3D model (JSmol)
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Abbreviations | DME | ||
1730743 | |||
ChEBI | |||
ChemSpider | |||
ECHA InfoCard | 100.003.696 | ||
EC Number | 204-065-8 | ||
KEGG | |||
MeSH | Dimethyl+ether | ||
PubChem CID
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RTECS number | PM4780000 | ||
UNII | |||
UN number | 1033 | ||
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Properties | |||
C2H6O | |||
Molar mass | 46.07 g·mol−1 | ||
Appearance | Colorless gas | ||
Odor | Typical | ||
Density | 2.1146 kg/m3 (gas, 0 °C, 1013 mbar) 0.735 g/mL (liquid, -25 °C) |
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Melting point | −141 °C; −222 °F; 132 K | ||
Boiling point | −24 °C; −11 °F; 249 K | ||
71 g/L (at 20 °C (68 °F)) | |||
log P | 0.022 | ||
Vapor pressure | >100 kPa | ||
-26.3·10−6 cm3/mol | |||
1.30 D | |||
Thermochemistry | |||
65.57 J K−1 mol−1 | |||
Std enthalpy of
formation (ΔfH |
−184.1 kJ mol−1 | ||
Std enthalpy of
combustion (ΔcH |
−1.4604 MJ mol−1 | ||
Hazards | |||
Safety data sheet |
See: data page ≥99% Sigma-Aldrich |
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GHS pictograms | |||
GHS signal word | Danger | ||
H220 | |||
P210, P410+403 | |||
NFPA 704 | |||
Flash point | −41 °C (−42 °F; 232 K) | ||
350 °C (662 °F; 623 K) | |||
Explosive limits | 27% | ||
Related compounds | |||
Related ethers
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Diethyl ether |
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Related compounds
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Ethanol |
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Supplementary data page | |||
Refractive index (n), Dielectric constant (εr), etc. |
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Thermodynamic
data |
Phase behaviour solid–liquid–gas |
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UV, IR, NMR, MS | |||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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what is ?) | (|||
Infobox references | |||
Dimethyl oxide
Dymel A
Methyl ether
Mether
Dimethyl ether (DME), also known as methoxymethane, is the organic compound with the formula CH3OCH3, simplified to C2H6O. The simplest ether, it is a colorless gas that is a useful precursor to other organic compounds and an aerosol propellant that is currently being demonstrated for use in a variety of fuel applications. It is an isomer of ethanol.
Approximately 50,000 tons were produced in 1985 in Western Europe by dehydration of methanol:
The required methanol is obtained from synthesis gas (syngas). In principle, the methanol could be obtained from organic waste or biomass. Other possible improvements call for a dual catalyst system that permits both methanol synthesis and dehydration in the same process unit, with no methanol isolation and purification.
Both the one-step and two-step processes above are commercially available. Currently, there is more widespread application of the two-step process, since it is relatively simple and start-up costs are relatively low. There is also a one-step liquid-phase process in development.
The largest use of dimethyl ether is as the feedstock for the production of the methylating agent, dimethyl sulfate, which entails its reaction with sulfur trioxide:
Dimethyl ether can also be converted into acetic acid using carbonylation technology related to the Monsanto acetic acid process:
Dimethyl ether is a low-temperature solvent and extraction agent, applicable to specialised laboratory procedures. Its usefulness is limited by its low boiling point (−23 °C (−9 °F)), but the same property facilitates its removal from reaction mixtures. Dimethyl ether is the precursor to the useful alkylating agent, trimethyloxonium tetrafluoroborate.