Ethylene glycol dimethyl ether
Structural formula | ||||||||||||||||||||||
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General | ||||||||||||||||||||||
Surname | Ethylene glycol dimethyl ether | |||||||||||||||||||||
other names |
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Molecular formula | C 4 H 10 O 2 | |||||||||||||||||||||
Brief description |
colorless liquid with an ethereal odor |
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properties | ||||||||||||||||||||||
Molar mass | 90.12 g mol −1 | |||||||||||||||||||||
Physical state |
liquid |
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density |
0.87 g cm −3 (20 ° C) |
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Melting point |
−58 ° C |
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boiling point |
84 ° C |
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Vapor pressure |
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solubility |
miscible with water |
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Refractive index |
1.3770 (25 ° C) |
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safety instructions | ||||||||||||||||||||||
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Authorization procedure under REACH |
of particular concern : toxic for reproduction ( CMR ) |
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C |
Ethylene glycol , also known as 1,2-dimethoxyethane , DME , EGDME , glyme , monoglyme or Dimethylglycol (rare dimethyl cellosolve ), is a colorless, clear, completely water-miscible liquid as the aprotic solvent is used. It is often used as a high-boiling substitute for diethyl ether or THF , for example in organometallic chemistry ( Grignard reactions ) and for palladium-catalyzed reactions ( Suzuki , Stille coupling ).
Presentation and extraction
The industrial production of ethylene glycol dimethyl ether takes place through the reaction of ethylene oxide with dimethyl ether .
properties
Physical Properties
Ethylene glycol dimethyl ether is a colorless liquid that smells like ether and boils at 84 ° C under normal pressure . According to Antoine, the vapor pressure function results from log 10 (P) = A− (B / (T + C)) (P in bar, T in K) with A = 3.83775, B = 1260.52 and C = −37.322 in the temperature range from 225 to 366 K.
property | Type | Value [unit] | Remarks |
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Standard enthalpy of formation | Δ f H 0 liquid Δ f H 0 gas |
−379.56 kJ mol −1 −342.8 kJ mol −1 |
as a liquid as a gas |
Enthalpy of combustion | Δ c H 0 liquid | −2623.6 kJ mol −1 | as a liquid |
Heat capacity | c p | 193.3 J mol −1 K −1 (25 ° C) 2.14 J g −1 K −1 (25 ° C) |
as a liquid |
Critical temperature | T c | 537 K | |
Critical pressure | p c | 39.6 bar | |
Critical volume | V c | 0.271 mol −1 | |
Critical density | ρ c | 2.25 mol·l −1 | |
Enthalpy of evaporation | Δ V H | 32.42 kJ mol −1 | at normal pressure boiling point |
Chemical properties
The compound can form explosive peroxides when exposed to light when standing in air .
Safety-related parameters
Ethylene glycol dimethyl ether forms highly flammable vapor-air mixtures. The compound has a flash point of −2 ° C. The explosion range is between 1.6% by volume (60 g · m −3 ) as the lower explosion limit (LEL) and 10.4% by volume (390 g · m −3 ) as the upper explosion limit (UEL). The limit gap width was determined to be 0.73 mm. This results in an assignment to explosion group IIB. The ignition temperature is 195 ° C. The substance therefore falls into temperature class T4.
use
DME is an excellent solvent that is almost infinitely miscible with both water and many organic compounds. This makes it possible, for example, to convert organic compounds with salts . It can also be used for oligo- and polysaccharides . DME is used, for example, as part of the electrolyte in lithium manganese dioxide cells .
safety instructions
1,2-Dimethoxyethane is harmful if inhaled and in higher concentrations can lead to anesthesia . It can also harm fertility and the unborn child. Alcohol consumption by the mother increases the damaging effect on the child.
Individual evidence
- ↑ a b c d e f g h i j k l m n o p q Entry on ethylene glycol dimethyl ether in the GESTIS substance database of the IFA , accessed on April 1, 2019(JavaScript required) .
- ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-188.
- ↑ Entry on 1,2-dimethoxyethane in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
- ↑ Entry in the SVHC list of the European Chemicals Agency , accessed on October 17, 2015.
- ↑ Rebsdat, S .; Mayer, D .: Ethylene Glycol , in: Ullmanns Enzyklopädie der Technischen Chemie , Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 20128; doi : 10.1002 / 14356007.a10_101 .
- ^ Stull, Daniel R .: Vapor Pressure of Pure Substances. Organic and Inorganic Compounds in Ind. Eng. Chem. 39 (1947) 517-540, doi : 10.1021 / ie50448a022 .
- ↑ a b c d e f g Steele, WV; Chirico, RD; Knipmeyer, SE; Nguyen, A .; Smith, NK: Thermodynamic properties and ideal-gas enthalpies of formation for butyl vinyl ether, 1,2-dimethoxyethane, methyl glycolate, bicyclo [2.2.1] hept-2-ene, 5-vinylbicyclo [2.2.1] hept-2 -ene, trans-azobenzene, butyl acrylate, di-tert-butyl ether, and hexane-1,6-diol in J. Chem. Eng. Data 41 (1996) 1285-1302, doi : 10.1021 / je960117w .
- ↑ a b Kusano, K .; Suurkuusk, J .; Wadsö, I .: Thermochemistry of solutions of biochemical model compounds. 2. Alkoxyethanols and 1,2-dialkoxyethanes in water in J. Chem. Thermodyn. 5 (1973) 757-767, doi : 10.1016 / S0021-9614 (73) 80017-5 .
- ^ V. Majer, V. Svoboda: Enthalpies of Vaporization of Organic Compounds: A Critical Review and Data Compilation . Blackwell Scientific Publications, Oxford 1985, pp. 300 .
- ↑ PG Urben; MJ Pitt: Bretherick's Handbook of Reactive Chemical Hazards . 8th edition, Vol. 1, Butterworth / Heinemann 2017, ISBN 978-0-08-100971-0 , p. 370.
- ↑ a b c E. Brandes, W. Möller: Safety-related parameters. Volume 1: Flammable Liquids and Gases. Wirtschaftsverlag NW - Verlag für neue Wissenschaft, Bremerhaven 2003.
- ↑ Panasonic product safety data sheet for CR batteries April 1st, 2016