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Dimethylether

Dimethyl ether
Skeletal formula of dimethyl ether with all implicit hydrogens shown
Ball and stick model of dimethyl ether
Names
Preferred IUPAC name
Methoxymethane
Other names
Dimethyl ether
R-E170
Demeon

Dimethyl oxide
Dymel A
Methyl ether
Mether

Wood ether
Identifiers
3D model (JSmol)
Abbreviations DME
1730743
ChEBI
ChemSpider
ECHA InfoCard 100.003.696
EC Number 204-065-8
KEGG
MeSH Dimethyl+ether
PubChem CID
RTECS number PM4780000
UNII
UN number 1033
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)
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
−184.1 kJ mol−1
−1.4604 MJ mol−1
Hazards
Safety data sheet See: data page
≥99% Sigma-Aldrich
GHS pictograms The flame pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word Danger
H220
P210, P410+403
NFPA 704
Flammability code 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g., propane Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g., calcium Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point −41 °C (−42 °F; 232 K)
350 °C (662 °F; 623 K)
Explosive limits 27%
Related compounds
Related ethers
Diethyl ether

Polyethylene glycol

Related compounds
Ethanol

Methanol

Supplementary data page
Refractive index (n),
Dielectric constantr), etc.
Thermodynamic
data
Phase behaviour
solid–liquid–gas
UV, IR, NMR, MS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
YesY  (what is YesYN ?)
Infobox references

Dimethyl oxide
Dymel A
Methyl ether
Mether

Polyethylene glycol

Methanol

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.


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Wikipedia

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