Diethyl ether

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Diethyl ether
Skeletal formula
Ball-and-stick model
style="background: #F8EABA; text-align: center;" colspan="2" | Identifiers
CAS number 60-29-7 YesY
PubChem 3283
ChemSpider 3168
RTECS number KI5775000
SMILES Script error: No such module "collapsible list".
InChI Script error: No such module "collapsible list".
InChI key RTZKZFJDLAIYFH-UHFFFAOYAB
style="background: #F8EABA; text-align: center;" colspan="2" | Properties
Molecular formula C4H10O
Molar mass 74.12 g mol−1
Appearance Colorless liquid
Density 0.7134 g/cm3, liquid
Melting point

-116.3 °C, 157 K, -177 °F

Boiling point

34.6 °C, 308 K, 94 °F

Solubility in water 6.9 g/100 ml (20 °C)
Refractive index (nD) 1.353 (20 °C)
Viscosity 0.224 cP (25 °C)
style="background: #F8EABA; text-align: center;" colspan="2" | Structure
Dipole moment 1.15 D (gas)
style="background: #F8EABA; text-align: center;" colspan="2" | Hazards
MSDS External MSDS
R-phrases R12 R19 R20 R22 R66 R67
S-phrases S9 S16 S29 S33
NFPA 704
4
2
1
Flash point -45 °C[1]
Autoignition
temperature
160 °C[1]
style="background: #F8EABA; text-align: center;" colspan="2" | Related compounds
Related Ethers Dimethyl ether
Methoxypropane
Related compounds Diethyl sulfide
 YesY (what is this?)  (verify)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Diethyl ether, also known simply as ether, is the organic compound with the formula (C2H5)2O. It is a colorless and highly flammable liquid with a low boiling point and a characteristic odor. It is the most common member of a class of chemical compounds known generically as ethers. It is a common solvent and was once used as a general anesthetic. Ether is sparingly soluble in water (6.9 g/100 mL).

History

Alchemist Raymundus Lullus is credited with discovering the compound in AD 1275, although there is no contemporary evidence of this. It was first synthesized in 1540 by Valerius Cordus, who called it "sweet oil of vitriol" (oleum dulce vitrioli) — the name reflects the fact that it is obtained by distilling a mixture of ethanol and sulfuric acid (then known as oil of vitriol)—and noted some of its medicinal properties. At about the same time, Theophrastus Bombastus von Hohenheim, better known as Paracelsus, discovered ether's analgesic properties. The name ether was given to the substance in 1730 by August Siegmund Frobenius.

Metabolism

A cytochrome P450 enzyme is proposed to metabolize diethyl ether.[2]

Diethyl ether inhibits alcohol dehydrogenase, and thus slows the metabolism of ethanol.[3] It also inhibits metabolism of other drugs requiring oxidative metabolism.[4]

Applications

It is particularly important as a solvent in the production of cellulose plastics such as cellulose acetate.[5]

As a fuel

Diethyl ether has a high cetane number of 85 - 96 and is used as a starting fluid for diesel and gasoline engines[6] because of its high volatility and low autoignition temperature. For the same reason it is also used as a component of the fuel mixture for carbureted compression ignition model engines.

Laboratory uses

Diethyl ether is a common laboratory solvent. It has limited solubility in water, thus it is commonly used for liquid-liquid extraction. Being less dense than water, the ether layer is usually on top. Diethyl ether is a common solvent for the Grignard reaction, and for many other reactions involving organometallic reagents. Due to its immiscibility with water and the fact that non-polar organic compounds are highly soluble in it, ether is also used in the production of freebase cocaine, and is listed as a Table II precursor under the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances.[7] However, for that purpose it has been largely replaced by cheaper, safer, uncontrolled hydrocarbons.

Anesthetic use

File:Ether monument-Boston.JPG
Panel from monument in Boston commemorating Morton's demonstration of ether's anesthetic use.

William T.G. Morton participated in a public demonstration of ether anesthesia on October 16, 1846 at the Ether Dome in Boston, Massachusetts. However, Crawford Williamson Long, M.D., is now known to have demonstrated its use privately as a general anesthetic in surgery to officials in Georgia, as early as March 30, 1842, and Long publicly demonstrated ether's use as a surgical anesthetic on numerous occasions before 1846.[8]

Ether was sometimes used in place of chloroform because it had a higher therapeutic index, a larger difference between the recommended dosage and a toxic overdose. Ether is still the preferred anesthetic in some developing nations due to its high therapeutic index (~1.5-2.2) [9][dubious ] and low price. Because of its associations with Boston, the use of ether became known as the "Yankee Dodge."

Ether could also be mixed with other anaesthetic agents such as chloroform to make C.E. mixture, or chloroform and alcohol to make A.C.E. mixture.

Today, ether is rarely used. The use of flammable ether was displaced by nonflammable anesthetics such as halothane. Additionally, ether had many undesirable side effects, such as postanesthetic nausea and vomiting. Modern anesthetic agents, such as methyl propyl ether (Neothyl) and methoxyflurane (Penthrane) reduce these side effects.[8]

Recreational use

The anesthetic effects of ether have made it a recreational drug, although not a popular one. Diethyl ether is not as toxic as other solvents used as recreational drugs.[citation needed]

Ether, mixed with ethanol, was marketed in the 19th century as a cure-all and recreational drug[citation needed], during one of Western society's temperance movements. At the time, it was considered improper for women to consume alcoholic beverages at social functions, and sometimes ether-containing drugs would be consumed instead.[citation needed] A cough medicine called Hoffmann's Drops was marketed at the time as one of these drugs, and contained both ether and alcohol in its capsules.[10] Ether tends to be difficult to consume alone, and thus was often mixed with drugs like ethanol for recreational use. Ether may also be used as an inhalant.

In the 19th century and early 20th century ether drinking was popular among Polish peasants[11] . It is a traditional and still relatively popular recreational drug among Lemkos.[12] It is usually consumed in a small quantity (kropka, or “dot”) poured over milk, water with sugar or orange juice in a shot glass.

Production

Most diethyl ether is produced as a byproduct of the vapor-phase hydration of ethylene to make ethanol. This process uses solid-supported phosphoric acid catalysts and can be adjusted to make more ether if the need arises.[5] Vapor-phase dehydration of ethanol over some alumina catalysts can give diethyl ether yields of up to 95%.[13]

Diethyl ether can be prepared both in laboratories and on an industrial scale by the acid ether synthesis. Ethanol is mixed with a strong acid, typically sulfuric acid, H2SO4. The acid dissociates producing hydrogen ions, H+. A hydrogen ion protonates the electronegative oxygen atom of the ethanol, giving the ethanol molecule a positive charge:

CH3CH2OH + H+ → CH3CH2OH2+

A nucleophilic oxygen atom of unprotonated ethanol displaces a water molecule from the protonated (electrophilic) ethanol molecule, producing water, a hydrogen ion and diethyl ether.

CH3CH2OH2+ + CH3CH2OH → H2O + H+ + CH3CH2OCH2CH3

This reaction must be carried out at temperatures lower than 150 °C in order to ensure that an elimination product (ethylene) is not a product of the reaction. At higher temperatures, ethanol will dehydrate to form ethylene. The reaction to make diethyl ether is reversible, so eventually an equilibrium between reactants and products is achieved. Getting a good yield of ether requires that ether be distilled out of the reaction mixture before it reverts to ethanol, taking advantage of Le Chatelier's principle.

Another reaction that can be used for the preparation of ethers is the Williamson ether synthesis, in which an alkoxide (produced by dissolving an alkali metal in the alcohol to be used) performs a nucleophilic substitution upon an alkyl halide.

Safety

Diethyl ether is prone to peroxide formation, and can form explosive diethyl ether peroxide. Ether peroxides are higher boiling and are contact explosives when dry. Diethyl ether is typically supplied with trace amounts of the antioxidant BHT (2,6-di-tert-butyl-4-methylphenol), which reduces the formation of peroxides. Storage over NaOH precipitates the intermediate ether hydroperoxides. Water and peroxides can be removed by either distillation from sodium and benzophenone, or by passing through a column of activated alumina.[14]

Ether is extremely flammable. The autoignition temperature of ether is only 170 °C (338°F), so it can be ignited by a hot surface without a flame or spark. A common practice in chemical labs is to use steam (thus limiting the temperature to 100 °C (212 °F) when ether must be heated or distilled. The diffusion of diethyl ether in air is 0.918·10−5 m2/s (298K 101.325 kPa).

References

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External links

ar:ثنائي إيثيل الإيثر

bs:Dietil eter ca:Dietilèter cs:Diethylether de:Diethylether et:Dietüüleeter el:Διαιθυλαιθέρας es:Éter etílico fa:دی‌اتیل اتر fr:Éther diéthylique ko:다이에틸 에테르 id:Dietil eter it:Etere dietilico he:דיאתיל אתר lv:Dietilēteris lt:Dietileteris lmo:Eter dietilich hu:Dietil-éter mk:Диетил етер nl:Diethylether ja:ジエチルエーテル pl:Eter dietylowy pt:Éter etílico ru:Диэтиловый эфир simple:Diethyl ether sl:Dietil eter fi:Dietyylieetteri sv:Dietyleter tr:Dietil eter uk:Діетиловий ефір

zh:乙醚
  1. 1.0 1.1 "Ethyl Ether MSDS". J.T. Baker. Retrieved 2010-06-24. 
  2. 109. Aspergillus flavus mutant strain 241, blocked in aflatoxin biosynthesis, does not accumulate aflR transcript. Matthew P. Brown and Gary A. Payne, North Carolina State University, Raleigh, NC 27695 fgsc.net
  3. P. T. Normann, A. Ripel and J. Morland (1987). "Diethyl Ether Inhibits Ethanol Metabolism in Vivo by Interaction with Alcohol Dehydrogenase". Alcoholism: Clinical and Experimental Research. 11 (2): 163–166. doi:10.1111/j.1530-0277.1987.tb01282.x. 
  4. Larry K. Keefer, William A. Garland, Neil F. Oldfield, James E. Swagzdis, and Bruce A. Mico (1985). "Inhibition of N-Nitrosodimethylamine Metabolism in Rats by Ether Anesthesia" (PDF). Cancer Research. 45: 5457–60. 
  5. 5.0 5.1 "Ethers, by Lawrence Karas and W. J. Piel". Kirk‑Othmer Encyclopedia of Chemical Technology. John Wiley & Sons, Inc. 2004. 
  6. "Extra Strength Starting Fluid: How it Works". Valvovine. Retrieved 2007-09-05. 
  7. Microsoft Word - RedListE2007.doc
  8. 8.0 8.1 Hill, John W. and Kolb, Doris K. Chemistry for changing times: 10th edition. Page 257. Pearson: Prentice Hall. Upper saddle river, New Jersey. 2004.
  9. Calderone, F.A. J. Pharmacology Experimental Therapeutics, 1935, 55(1), 24-39, Jpet.aspetjournals.org
  10. Erowid Ether Vaults : Hoffmann's Drops
  11. Zandberg, Adrian (2010). ""Villages… Reek of Ether Vapours": Ether Drinking in Silesia before 1939". Medical History. 54 (3): 387–396. PMC 2890321Freely accessible. PMID 20592886. 
  12. Kaszycki, Nestor (2006-08-30). "Łemkowska Watra w Żdyni 2006 – pilnowanie ognia pamięci". Histmag.org – historia od podszewki (in Polish). Kraków, Poland: i-Press. Retrieved 2009-11-25. Dawniej eteru używało się w lecznictwie do narkozy, ponieważ ma właściwości halucynogenne, a już kilka kropel inhalacji wystarczyło do silnego znieczulenia pacjenta. Jednak eter, jak każda ciecz, może teoretycznie być napojem. Łemkowie tę teorię praktykują. Mimo to, nazywanie skroplonego eteru – „kropki” – ich „napojem narodowym” byłoby przesadą. Chociaż stanowi to pewną część mitu „bycia Łemkiem”. 
  13. Ethyl Ether, Chem. Economics Handbook. Menlo Park, Calif: SRI International. 1991. 
  14. Lua error in package.lua at line 80: module 'Module:Citation/CS1/Suggestions' not found.