Carbonic acid diethyl ester

Structural formula
General
Surname	Carbonic acid diethyl ester
other names	Diethyl carbonate Diatol
Molecular formula	C 5 H 10 O 3
Brief description	colorless liquid with an ethereal odor
External identifiers / databases
CAS number 105-58-8 EC number 203-311-1 ECHA InfoCard 100.003.011 PubChem 7766 Wikidata Q420616
properties
Molar mass	118.13 g mol −1
Physical state	liquid
density	0.9764 g cm −3
Melting point	−43 ° C
boiling point	125.8 ° C
Vapor pressure	11 h Pa (20 ° C)
solubility	practically insoluble in water soluble in ethanol, diethyl ether and chloroform
Refractive index	1.384 (20 ° C)
safety instructions
GHS labeling of hazardous substances Caution H and P phrases H: 226 P: 210
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

Carbonic acid diethyl ester (also diatol or diethyl carbonate ) is an organic - chemical compound . At room temperature it is in the form of a clear, ethereal-smelling liquid.

Presentation and extraction

It is produced by reacting phosgene with ethanol . A more recent process is based on urea , the reaction with ethanol taking place at 180 ° C over yttrium catalysts .

properties

Physical Properties

Diethyl carbonate is a colorless and low-viscosity liquid that boils at 126 ° 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 = 4.77616, B = 1721.904 and C = −37.959 in the temperature range from 263 to 399 K. The critical temperature is 296 ° C, the critical pressure is 34.6 bar. The heat capacity at 21 ° C is 210.9 J mol ⁻¹ K ⁻¹ or 1.78 J g ⁻¹ K ⁻¹ .

Chemical properties

At higher temperatures, carbonic acid diethyl ester breaks down to carbon dioxide , ethanol and ethene . The decomposition reaction proceeds according to a first-order time law . With an activation energy of 195 kJ mol ⁻¹ and an Arrhenius factor of 1.15 10 ¹³  s ⁻¹ , the half-lives of the decomposition are 95 h at 270 ° C, 5 h at 310 ° C, and 23 at 360 ° C min.

Safety-related parameters

Carbonic acid diethyl ester forms flammable vapor-air mixtures. The compound has a flash point below 25 ° C. The explosion range is between 1.4% by volume (69 g / m ³ ) as the lower explosion limit (LEL) and 11.7% by volume (570 g / m ³ ) as the upper explosion limit (UEL). The limit gap width was determined to be 0.83 mm. This results in an assignment to explosion group IIB. The ignition temperature is 445 ° C. The substance therefore falls into temperature class T2.

use

Carbonic acid diethyl ester is used as a solvent for cellulose nitrate and ether, synthetic and natural resins. It is also used in organic syntheses, for example in carboethoxylation , and in the synthesis of heterocycles .

It is also produced when phosgene is “defused” . This arises from the decomposition of chloroform under the influence of oxygen and the influence of light in addition to hydrochloric acid . By adding ethanol , the chloroform can be made "phosgene-proof", because the phosgene reacts immediately with the alcohol to form harmless diethyl carbonate.

The compound is also a component of electrolyte solutions for lithium batteries .

Individual evidence

1. ↑ ^{a b c d e f g h} Entry for CAS no. 105-58-8 in the GESTIS substance database of the IFA , accessed on April 25, 2016(JavaScript required) .
2. ↑ ^{a b c d} Entry on diethyl carbonate. In: Römpp Online . Georg Thieme Verlag, accessed on June 19, 2014.
3. ↑ Data sheet Diethyl carbonate from Sigma-Aldrich , accessed on May 29, 2011 ( PDF ).
4. ↑ Patent US2010 / 312001 A1, Bayer MaterialScience AG 2010.
5. ↑ Stull, DR: Vapor Pressure of Pure Substances Organic Compounds in Ind. Eng. Chem. 39 (1947) 517-540, doi : 10.1021 / ie50448a022 .
6. ↑ Cocero, MJ; Mato, F .; Garcia, I .; Cobos, JC: Thermodynamics of binary mixtures containing organic carbonates. 3. Isothermal vapor-liquid equilibria for diethyl carbonate + cyclohexane, + benzene, or + tetrachloromethane in J. Chem. Eng. Data 34 (1989) 443-445, doi : 10.1021 / je00058a021 .
7. ↑ Kolosovskii, NA; Udovenko, WW: Specific heat of liquids. II. In Zhur. Obshchei Khim. 4 (1934) 1027-1033.
8. ↑ JTD Cross, R. Hunter, VR Stimson: The thermal decomposition of simple carbonate esters. In: Australian Journal of Chemistry. 29, 1976, p. 1477, doi : 10.1071 / CH9761477 .
9. ^ ^{A b c d} E. Brandes, W. Möller: Safety-related parameters - Volume 1: Flammable liquids and gases , Wirtschaftsverlag NW - Verlag für neue Wissenschaft GmbH, Bremerhaven 2003.
10. ↑ Tetsuya Kawamura, Arihisa Kimura, Minato Egashira, Shigeto Okada, Jun-Ichi Yamaki: Thermal stability of alkyl carbonate mixed-solvent electrolytes for lithium ion cells. In: Journal of Power Sources. 104, 2002, pp. 260-264, doi : 10.1016 / S0378-7753 (01) 00960-0 . bibcode : 2002JPS ... 104..260K .
11. ↑ Boris Ravdel, KM Abraham a. a .: Thermal stability of lithium-ion battery electrolytes. In: Journal of Power Sources. 119-121, 2003, pp. 805-810, doi : 10.1016 / S0378-7753 (03) 00257-X .