Diethyl ether
Overview
 
Diethyl ether, also known as ethyl ether, simply ether, or ethoxyethane, is an organic compound
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...

 in the ether
Ether
Ethers are a class of organic compounds that contain an ether group — an oxygen atom connected to two alkyl or aryl groups — of general formula R–O–R'. A typical example is the solvent and anesthetic diethyl ether, commonly referred to simply as "ether"...

 class with the formula . It is a colorless, highly volatile
Volatility (chemistry)
In chemistry and physics, volatility is the tendency of a substance to vaporize. Volatility is directly related to a substance's vapor pressure. At a given temperature, a substance with higher vapor pressure vaporizes more readily than a substance with a lower vapor pressure.The term is primarily...

 flammable liquid
Flammable liquid
Generally, a flammable liquid is a liquid that can catch fire.In the USA, there is a precise definition of flammable liquid as one with a flash point below 100 degrees Fahrenheit. Less-flammable liquids are defined as combustible liquids...

 with a characteristic odor. It is commonly used as a solvent
Solvent
A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...

 and was once used as a general anesthetic.
The compound may have been created by either Jābir ibn Hayyān in the 8th century or Raymundus Lullus
Ramon Llull
Ramon Llull was a Majorcan writer and philosopher, logician and tertiary Franciscan. He wrote the first major work of Catalan literature. Recently-surfaced manuscripts show him to have anticipated by several centuries prominent work on elections theory...

 in 1275, although there is no contemporary evidence of this.
Encyclopedia
Diethyl ether, also known as ethyl ether, simply ether, or ethoxyethane, is an organic compound
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...

 in the ether
Ether
Ethers are a class of organic compounds that contain an ether group — an oxygen atom connected to two alkyl or aryl groups — of general formula R–O–R'. A typical example is the solvent and anesthetic diethyl ether, commonly referred to simply as "ether"...

 class with the formula . It is a colorless, highly volatile
Volatility (chemistry)
In chemistry and physics, volatility is the tendency of a substance to vaporize. Volatility is directly related to a substance's vapor pressure. At a given temperature, a substance with higher vapor pressure vaporizes more readily than a substance with a lower vapor pressure.The term is primarily...

 flammable liquid
Flammable liquid
Generally, a flammable liquid is a liquid that can catch fire.In the USA, there is a precise definition of flammable liquid as one with a flash point below 100 degrees Fahrenheit. Less-flammable liquids are defined as combustible liquids...

 with a characteristic odor. It is commonly used as a solvent
Solvent
A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...

 and was once used as a general anesthetic.

History

The compound may have been created by either Jābir ibn Hayyān in the 8th century or Raymundus Lullus
Ramon Llull
Ramon Llull was a Majorcan writer and philosopher, logician and tertiary Franciscan. He wrote the first major work of Catalan literature. Recently-surfaced manuscripts show him to have anticipated by several centuries prominent work on elections theory...

 in 1275, although there is no contemporary evidence of this. It was first synthesized in 1540 by Valerius Cordus
Valerius Cordus
Valerius Cordus was a German physician and botanist who authored one of the greatest pharmacopoeias and one of the most celebrated herbals in history...

 and, 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
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...

 and sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...

 (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
Paracelsus
Paracelsus was a German-Swiss Renaissance physician, botanist, alchemist, astrologer, and general occultist....

, discovered ether's analgesic
Analgesic
An analgesic is any member of the group of drugs used to relieve pain . The word analgesic derives from Greek an- and algos ....

 properties in chickens. The name ether was given to the substance in 1730 by August Sigmund Frobenius
August Sigmund Frobenius
August Sigmund Frobenius , FRS, also known as Sigismond Augustus Frobenius, Joannes Sigismundus Augustus Frobenius, and Johann Sigismund August Froben, was a German-born chemist in the 18th century who is known for the first detailed description of the properties of diethyl ether and the naming of...

.

Applications

It is particularly important as a solvent in the production of cellulose plastics such as cellulose acetate
Cellulose acetate
Cellulose acetate , first prepared in 1865, is the acetate ester of cellulose. Cellulose acetate is used as a film base in photography, as a component in some adhesives, and as a frame material for eyeglasses; it is also used as a synthetic fiber and in the manufacture of cigarette filters and...

.

As a fuel

Diethyl ether has a high cetane number
Cetane number
Cetane number or CN is a measurement of the combustion quality of diesel fuel during compression ignition. It is a significant expression of diesel fuel quality among a number of other measurements that determine overall diesel fuel quality.- Definition :...

 of 85-96 and is used as a starting fluid for diesel and gasoline engines because of its high volatility and low autoignition temperature
Autoignition temperature
The autoignition temperature or kindling point of a substance is the lowest temperature at which it will spontaneously ignite in a normal atmosphere without an external source of ignition, such as a flame or spark. This temperature is required to supply the activation energy needed for combustion...

. For the same reason it is also used as a component of the fuel mixture for carbureted compression ignition model engines
Carbureted compression ignition model engines
Simple compression ignition engines are made for model propulsion, usually model aircraft but also model boats. These are quite similar to the typical glow-plug engine that runs on a mixture of methanol-based fuels with a hot wire filament to provide ignition...

.

Laboratory uses

Diethyl ether is a common laboratory solvent
Solvent
A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...

. It has limited solubility
Solubility
Solubility is the property of a solid, liquid, or gaseous chemical substance called solute to dissolve in a solid, liquid, or gaseous solvent to form a homogeneous solution of the solute in the solvent. The solubility of a substance fundamentally depends on the used solvent as well as on...

 in water (6.9 g/100 mL) and dissolves 1.5 g/100 mL water at 25 °C. Therefore, it is commonly used for liquid-liquid extraction
Liquid-liquid extraction
Liquid–liquid extraction, also known as solvent extraction and partitioning, is a method to separate compounds based on their relative solubilities in two different immiscible liquids, usually water and an organic solvent. It is an extraction of a substance from one liquid phase into another liquid...

. When used with an aqueous solution, the organic layer is on top as the diethyl ether has a lower density than the water. It is also a common solvent for the Grignard reaction
Grignard reaction
The Grignard reaction is an organometallic chemical reaction in which alkyl- or aryl-magnesium halides add to a carbonyl group in an aldehyde or ketone. This reaction is an important tool for the formation of carbon–carbon bonds...

 in addition to other reactions involving organometallic reagents. Due to its application in the manufacturing of illicit substances, it is listed in the Table II precursor under the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances
United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances
The United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances of 1988 is one of three major drug control treaties currently in force. It provides additional legal mechanisms for enforcing the 1961 Single Convention on Narcotic Drugs and the 1971 Convention on...

.

Anesthetic use

William T.G. Morton
William T.G. Morton
William Thomas Green Morton was an American dentist who first publicly demonstrated the use of inhaled ether as a surgical anesthetic in 1846. The promotion of his questionable claim to have been the discoverer of anesthesia became an obsession for the rest of his life.- Life and work :Born in...

 participated in a public demonstration of ether anesthesia on October 16, 1846 at the Ether Dome
Ether Dome
The Ether Dome is an amphitheater in the Bulfinch Building at Massachusetts General Hospital in Boston. It served as the hospital's operating room from its opening in 1821 until 1867. It was the site of the first use of inhaled ether as a surgical anesthetic on 16 October 1846. William Thomas...

 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. British doctors were aware of the anesthetic properties of ether as early as 1840 where it was widely prescribed in conjunction with opium.

Diethyl ether was formerly sometimes used in place of chloroform
Chloroform
Chloroform is an organic compound with formula CHCl3. It is one of the four chloromethanes. The colorless, sweet-smelling, dense liquid is a trihalomethane, and is considered somewhat hazardous...

 because it had a higher therapeutic index
Therapeutic index
The therapeutic index is a comparison of the amount of a therapeutic agent that causes the therapeutic effect to the amount that causes death or toxicity ....

, a larger difference between the recommended dosage and a toxic overdose. Because of its associations with Boston, the use of ether became known as the "Yankee Dodge."

Diethyl ether depresses the myocardium and also increases treacheobronchial secretions.

Diethyl ether could also be mixed with other anesthetic agents such as chloroform
Chloroform
Chloroform is an organic compound with formula CHCl3. It is one of the four chloromethanes. The colorless, sweet-smelling, dense liquid is a trihalomethane, and is considered somewhat hazardous...

 to make C.E. mixture, or chloroform and alcohol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...

 to make A.C.E. mixture
A.C.E. mixture
A.C.E. mixture is an old anaesthetic agent for general anaesthesia, which was first suggested by Dr. George Harley and first used in England around 1860, and in 1864 it was recommended for use by the Royal Medical and Surgical Society’s Chloroform Committee...

.

Today, ether is rarely used. The use of flammable ether was displaced by nonflammable anesthetics such as halothane
Halothane
Halothane is an inhalational general anesthetic. Its IUPAC name is 2-bromo-2-chloro-1,1,1-trifluoroethane. It is the only inhalational anesthetic agent containing a bromine atom; there are several other halogenated anesthesia agents which lack the bromine atom and do contain the fluorine and...

. Diethyl ether was found to have many undesirable side effects, such as post-anesthetic nausea and vomiting. Modern anesthetic agents, such as methyl propyl ether (Neothyl) and methoxyflurane
Methoxyflurane
Methoxyflurane is a halogenated ether that was in clinical use as an volatile inhalational anesthetic from its introduction by Joseph F. Artusio et al in 1960 until around 1974. It was first synthesized in the late 1940s by William T...

 (Penthrane) reduce these side effects.

Medical use

It was once used in pharmaceuticals. A formulation of alcohol and mixture was known as "Spirit of ether" or Hoffman's drop. In the United States, it was removed from Pharmacopoeia prior to June 1917.

Recreational use

The anesthetic effects of ether have made it a recreational drug, although not a popular one.

Ether, mixed with ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...

, was marketed in the 19th century as a cure-all and recreational drug, during one of Western society's temperance movement
Temperance movement
A temperance movement is a social movement urging reduced use of alcoholic beverages. Temperance movements may criticize excessive alcohol use, promote complete abstinence , or pressure the government to enact anti-alcohol legislation or complete prohibition of alcohol.-Temperance movement by...

s. 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.

In the 19th century and early 20th century ether drinking was popular among Polish peasants. It is a traditional and still relatively popular recreational drug among Lemkos
Lemkos
Lemkos , one of several quantitatively and territorially small ethnic groups who also call themselves Rusyns , are one of the ethnic groups inhabiting the Carpathian Mountains...

. It is usually consumed in a small quantity (kropka, or "dot") poured over milk
Milk
Milk is a white liquid produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals before they are able to digest other types of food. Early-lactation milk contains colostrum, which carries the mother's antibodies to the baby and can reduce the risk of many...

, water with sugar or orange juice
Orange juice
Orange juice is a popular beverage made from oranges. It is made by extraction from the fresh fruit, by desiccation and subsequent reconstitution of dried juice, or by concentration of the juice and the subsequent addition of water to the concentrate...

 in a shot glass
Shot glass
A shot glass is a small glass designed to hold or measure spirits or liquor, which is either drunk straight from the glass or poured into a mixed drink....

.

Metabolism

A cytochrome P450 enzyme is proposed to metabolize diethyl ether.

Diethyl ether inhibits alcohol dehydrogenase
Alcohol dehydrogenase
Alcohol dehydrogenases are a group of dehydrogenase enzymes that occur in many organisms and facilitate the interconversion between alcohols and aldehydes or ketones with the reduction of nicotinamide adenine dinucleotide...

, and thus slows the metabolism of ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...

. It also inhibits metabolism of other drugs requiring oxidative metabolism.

Production

Most diethyl ether is produced as a byproduct of the vapor-phase hydration
Hydration reaction
In organic chemistry, a hydration reaction is a chemical reaction in which a hydroxyl group and a hydrogen cation are added to the two carbon atoms bonded together in the carbon-carbon double bond which makes up an alkene functional group. The reaction usually runs in a strong acidic, aqueous...

 of ethylene
Ethylene
Ethylene is a gaseous organic compound with the formula . It is the simplest alkene . Because it contains a carbon-carbon double bond, ethylene is classified as an unsaturated hydrocarbon. Ethylene is widely used in industry and is also a plant hormone...

 to make ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...

. This process uses solid-supported phosphoric acid
Phosphoric acid
Phosphoric acid, also known as orthophosphoric acid or phosphoric acid, is a mineral acid having the chemical formula H3PO4. Orthophosphoric acid molecules can combine with themselves to form a variety of compounds which are also referred to as phosphoric acids, but in a more general way...

 catalysts
Catalysis
Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations....

 and can be adjusted to make more ether if the need arises. Vapor-phase dehydration
Dehydration reaction
In chemistry and the biological sciences, a dehydration reaction is usually defined as a chemical reaction that involves the loss of water from the reacting molecule. Dehydration reactions are a subset of elimination reactions...

 of ethanol over some alumina
Aluminium oxide
Aluminium oxide is an amphoteric oxide with the chemical formula 23. It is commonly referred to as alumina, or corundum in its crystalline form, as well as many other names, reflecting its widespread occurrence in nature and industry...

 catalysts can give diethyl ether yields of up to 95%.

Diethyl ether can be prepared both in laboratories and on an industrial scale by the acid ether synthesis. Ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...

 is mixed with a strong acid, typically sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...

, H2SO4. The acid dissociates
Dissociation (chemistry)
Dissociation in chemistry and biochemistry is a general process in which ionic compounds separate or split into smaller particles, ions, or radicals, usually in a reversible manner...

 in the aqueous environment producing hydronium
Hydronium
In chemistry, a hydronium ion is the cation , a type of oxonium ion produced by protonation of water. This cation is often used to represent the nature of the proton in aqueous solution, where the proton is highly solvated...

 ions, H3O+. A hydrogen ion protonates
Protonation
In chemistry, protonation is the addition of a proton to an atom, molecule, or ion. Some classic examples include*the protonation of water by sulfuric acid:*the protonation of isobutene in the formation of a carbocation:2C=CH2 + HBF4 → 3C+ + BF4−*the protonation of ammonia in the...

 the electronegative
Electronegativity
Electronegativity, symbol χ , is a chemical property that describes the tendency of an atom or a functional group to attract electrons towards itself. An atom's electronegativity is affected by both its atomic number and the distance that its valence electrons reside from the charged nucleus...

 oxygen atom of the ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...

, giving the ethanol molecule a positive charge:
CH3CH2OH + H3O+ → CH3CH2OH2+ + H2O


A nucleophilic oxygen atom of unprotonated ethanol displaces
Single displacement reaction
A single-displacement reaction, also called single-replacement reaction, is a type of oxidation-reduction chemical reaction when an element or ion moves out of one compound and into another. This is usually written as...This will occur if A is more reactive than B...

 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
Ethylene
Ethylene is a gaseous organic compound with the formula . It is the simplest alkene . Because it contains a carbon-carbon double bond, ethylene is classified as an unsaturated hydrocarbon. Ethylene is widely used in industry and is also a plant hormone...

) 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
Chemical equilibrium
In a chemical reaction, chemical equilibrium is the state in which the concentrations of the reactants and products have not yet changed with time. It occurs only in reversible reactions, and not in irreversible reactions. Usually, this state results when the forward reaction proceeds at the same...

 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
Le Châtelier's principle
In chemistry, Le Chatelier's principle, also called the Chatelier's principle, can be used to predict the effect of a change in conditions on a chemical equilibrium. The principle is named after Henry Louis Le Chatelier and sometimes Karl Ferdinand Braun who discovered it independently...

.

Another reaction that can be used for the preparation of ethers is the Williamson ether synthesis
Williamson ether synthesis
The Williamson ether synthesis is an organic reaction, forming an ether from an organohalide and an alcohol. This reaction was developed by Alexander Williamson in 1850. Typically it involves the reaction of an alkoxide ion with a primary alkyl halide via an SN2 reaction...

, in which an alkoxide
Alkoxide
An alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They can be written as RO−, where R is the organic substituent. Alkoxides are strong bases and, when R is not bulky, good nucleophiles and good ligands...

 (produced by dissolving an alkali metal
Alkali metal
The alkali metals are a series of chemical elements in the periodic table. In the modern IUPAC nomenclature, the alkali metals comprise the group 1 elements, along with hydrogen. The alkali metals are lithium , sodium , potassium , rubidium , caesium , and francium...

 in the alcohol to be used) performs a nucleophilic substitution
Nucleophilic substitution
In organic and inorganic chemistry, nucleophilic substitution is a fundamental class of reactions in which an electron nucleophile selectively bonds with or attacks the positive or partially positive charge of an atom or a group of atoms called the leaving group; the positive or partially positive...

 upon an alkyl halide.

Safety

Diethyl ether is susceptible to peroxide
Organic peroxide
Organic peroxides are organic compounds containing the peroxide functional group . If the R' is hydrogen, the compound is called an organic hydroperoxide. Peresters have general structure RCOOR. The O-O bond easily breaks and forms free radicals of the form RO·...

 formation, and can form explosive diethyl ether peroxide
Diethyl ether peroxide
Diethyl ether peroxides are a class of organic peroxides that slowly form in diethyl ether upon storage under air, light, or in the presence of metal by autoxidation.- Diethyl ether hydroperoxide :...

. Ether peroxides are higher boiling and are contact explosives when dry. Diethyl ether is typically supplied with trace amounts of the antioxidant
Antioxidant
An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...

 butylated hydroxytoluene
Butylated hydroxytoluene
Butylated hydroxytoluene , also known as butylhydroxytoluene, is a lipophilic organic compound that is primarily used as an antioxidant food additive as well as an antioxidant additive in cosmetics, pharmaceuticals, jet fuels, rubber, petroleum products, electrical transformer oil, and embalming...

 (BHT), which reduces the formation of peroxides. Storage over sodium hydroxide precipitates the intermediate ether hydroperoxides. Water and peroxides can be removed by either distillation from sodium
Sodium
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...

 and benzophenone
Benzophenone
Benzophenone is the organic compound with the formula 2CO, generally abbreviated Ph2CO. Benzophenone is a widely used building block in organic chemistry, being the parent diarylketone.-Uses:...

, or by passing through a column of activated alumina
Activated alumina
Activated alumina is manufactured from aluminium hydroxide by dehydroxylating it in a way that produces a highly porous material; this material can have a surface area significantly over 200 square metres/g. The compound is used as a desiccant and as a filter of fluoride, arsenic and selenium in...

.

Diethyl ether is extremely flammable. The autoignition temperature of diethyl ether is 160 °C (320 °F), therefore 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).

External links

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