ETHYL ETHER: PROPERTIES, STRUCTURE, PRODUCTION, USES - CHEMISTRY - 2025

The ethyl ether, also known as diethyl ether, is an organic compound whose chemical formula is C ₄ H ₁₀ O. characterized as a colorless liquid and volatile, and therefore, their bottles must be kept closed as tightly as possible.

This ether is classified as a member of the dialkyl ethers; that is, they have the formula ROR ', where R and R' represent different carbon segments. And as described by its second name, diethyl ether, it is two radicals - ethyl that bind to the oxygen atom.

Source: Choij from Wikipedia

Ethyl ether was initially used as a general anesthetic, introduced in 1846 by William Thomas Green Morton. However, due to its flammability, its use was discarded, replacing it with other less dangerous anesthetics.

This compound has also been used to estimate the time of blood circulation, during the evaluation of the cardiovascular status of patients.

Within the body, diethyl ether can be transformed into carbon dioxide and metabolites; the latter end up being excreted in the urine. However, most of the administered ether is exhaled into the lungs, without undergoing any modification.

On the other hand, it is used as a solvent for soaps, oils, perfumes, alkaloids and gums.

Structure of ethyl ether

Source: Benjah-bmm27 from Wikipedia

In the upper image there is a representation with a spheres and bars model of the molecular structure of ethyl ether.

As can be seen, the red sphere, corresponding to the oxygen atom, has two ethyl groups linked on both sides. All the links are simple, flexible, and freely rotating around the σ axes.

These rotations give rise to stereoisomers known as conformers; that more than isomers, they are alternative spatial states. The structure of the image corresponds exactly to the anti conformer, in which all its groups of atoms are staggered (separated from each other).

What would the other conformer be? The eclipsed one, and although its image is not available, it is enough to visualize it in the shape of a U. At the upper ends of the U, the methyl groups, -CH ₃, would be located, which would experience steric repulsions (they would collide in space).

Therefore, it is expected that the CH ₃ CH ₂ OCH ₂ CH ₃ molecule will adopt the anti conformation most of the time.

Intermolecular forces

By what intermolecular forces are the ethyl ether molecules governed in the liquid phase? They are kept in the liquid mainly thanks to dispersion forces, since their dipole moment (1.5D) lacks a sufficiently deficient region in electron density (δ +)

This is because no carbon atom in the ethyl groups gives up its electronic density too much to the oxygen atom. The foregoing is evident with the electrostatic potential map of ethyl ether at hand (lower image). Note the absence of a blue region.

Source: Jaelkoury at English Wikipedia

Oxygen cannot form hydrogen bonds either, again, because there are no OH bonds available in the molecular structure. Therefore, it is the instantaneous dipoles and their molecular mass that favor their dispersion forces.

Despite this, it is highly soluble in water. Why? Because its oxygen atom, with a higher electron density, can accept hydrogen bonds from a water molecule:

(CH ₃ CH ₂) ₂ O ^δ- - ^{δ +} H-OH

These interactions are responsible for 6.04g of this ether to dissolve in 100mL of water.

Physical and chemical properties

Other names

-Diethyl ether

-Ethoxyethane

-Ethyl oxide

Molecular formula

C ₄ H ₁₀ O or (C ₂ H ₅) ₂ O.

Molecular weight

74.14 g / mol.

Physical appearance

Colorless liquid.

Odor

Sweet and spicy.

Taste

Burning and sweet.

Boiling point

94.3 ° F (34.6 ° C) at 760 mmHg.

Melting point

-177.3 ° F (-116.3 ° C). Stable crystals.

ignition point

-49ºF (closed container).

Water solubility

6.04 g / 100mL at 25 ° C.

Solubility in other liquids

Miscible with short chain aliphatic alcohols, benzene, chloroform, petroleum ether, fat solvent, many oils, and concentrated hydrochloric acid.

Soluble in acetone and very soluble in ethanol. It is also soluble in naphtha, benzene and oils.

Density

0.714 mg / mL at 68 ° F (20 ° C).

Vapor density

2.55 (in relation to air taken with density 1).

Vapor pressure

442 mmHg at 68ºF. 538 mmHg at 25 ° C. 58.6 kPa at 20 ° C.

Stability

It is slowly oxidized by the action of air, humidity and light with the formation of peroxides.

Peroxide formation can occur in ether containers that have been opened and that remain in storage for more than six months. Peroxides can be detonated by friction, impact, or heating.

Avoid contact with: zinc, halogens, non-metallic oxyhalides, strong oxidizing agents, chromyl chloride, tementine oils, metal nitrates and chlorides.

Auto ignition

356 ° F (180 ° C).

Decomposition

When heated it decomposes, emitting acrid and irritating smoke.

Viscosity

0.2448 cPoise at 20ºC.

Heat of combustion

8,807 Kcal / g.

Heat of vaporization

89.8 cal / g at 30 ° C.

Surface tension

17.06 dynes / cm at 20º C.

Ionization potential

9.53 eV.

Odor threshold

0.83 ppm (purity is not given).

Refractive index

1,355 at 15 ° C.

Obtaining

From ethyl alcohol

Ethyl ether can be obtained from ethyl alcohol, in the presence of sulfuric acid as a catalyst. Sulfuric acid in an aqueous medium dissociates producing the hydronium ion, H ₃ O ⁺.

The anhydrous ethyl alcohol flows through the sulfuric acid solution, heated between 130 ° C and 140 ° C, producing the protonation of ethyl alcohol molecules. Subsequently, another non-protonated ethyl alcohol molecule reacts with the protonated molecule.

When this happens, the nucleophilic attack of the second ethyl alcohol molecule promotes the release of water from the first molecule (the protonated one); as a result, a protonated ethyl ether (CH ₃ CH ₂ OHCH ₂ CH ₃) is formed, with the oxygen partially charged positive.

However, this synthesis method loses efficiency because the sulfuric acid is gradually diluted with the water produced in the process (product of the dehydration of ethyl alcohol).

The reaction temperature is critical. At temperatures below 130 ° C the reaction is slow and for the most part ethyl alcohol will distil out.

Above 150 ° C, sulfuric acid causes the formation of ethylene (the double bond alkene), instead of combining with ethyl alcohol to form ethyl ether.

From ethylene

In the reverse process, that is, the hydration of ethylene in the vapor phase, ethyl ether can be formed as a side product in addition to ethyl alcohol. In fact, this synthetic route produces most of this organic compound.

This process uses phosphoric acid catalysts attached to a solid support, which can be adjusted to produce more ether.

Vapor phase dehydration of ethanol in the presence of alumina catalysts can give a 95% yield in the production of ethyl ether.

Toxicity

It can cause skin and eye irritation by contact. Contact with the skin can cause drying and cracking. Ether does not usually penetrate the skin, as it is quickly evaporated.

Eye irritation caused by ether is usually mild, and in the case of severe irritation, the damage is generally reversible.

Its ingestion produces narcotic effects and stomach irritation. Severe ingestion can cause kidney damage.

Inhalation of ether can cause nose and throat irritation. In the case of inhalation of ether, the following may occur: drowsiness, excitement, dizziness, vomiting, irregular breathing and increased salivation.

High exposure can cause unconsciousness and even death.

OSHA sets an airborne occupational exposure limit of 800 ppm averaged over an 8-hour shift.

Eye irritation levels: 100 ppm (human). Eye irritation levels: 1200 mg / m ³ (400 ppm).

Applications

Organic solvent

It is an organic solvent that is used to dissolve bromine, iodine and other halogens; most lipids (fats), resins, pure rubbers, some alkaloids, gums, perfumes, cellulose acetate, cellulose nitrate, hydrocarbons and colorants.

In addition, it is used in the extraction of active principles from animal and plant tissues, due to its lower density than water and it floats on it, leaving the desired substances dissolved in the ether.

General anesthesia

It has been used as a general anesthetic since 1840, replacing chloroform as it has a therapeutic advantage. However, it is a flammable substance, and therefore encounters severe difficulties in its use within clinical settings.

In addition, it produces some undesirable postoperative side effects such as nausea and vomiting in patients.

For these reasons, the use of ether as a general anesthetic has been discarded, replacing it with other anesthetics such as halothane.

Ether Spirit

Ether mixed with ethanol was used to form the solution called spirit of ether, used in the treatment of gastric flatulence and milder forms of gastralgia.

Assessment of blood circulation

Ether has been used to evaluate blood circulation between an arm and the lungs. Ether is injected into one arm, drawing blood to the right atrium, then the right ventricle, and from there to the lungs.

The time that elapses from the injection of the ether to the capture of the odor of the ether in the expired air is approximately 4 to 6 s.

Teaching laboratories

Ether is used in teaching laboratories in many experiments; for example, in the demonstration of Mendel's laws of genetics.

Ether is used to lull the flies of the genus Drosophila and allow the necessary crosses between them, thus putting into evidence the laws of genetics

References

1. Graham Solomons TW, Craig B. Fryhle. (2011). Organic Chemistry. Amines. (10 ^th edition.). Wiley Plus.
2. Carey F. (2008). Organic Chemistry. (Sixth edition). Mc Graw Hill.
3. The Sevier. (2018). Diethyl ether. Science Direct. Recovered from: sciencedirect.com
4. The Editors of Encyclopaedia Britannica. (2018). Ethyl ether. ncyclopædia Britannica. Recovered from: britannica.com
5. PubChem (2018). Ether. Recovered from: pubchem.ncbi.nlm.nih.gov
6. Wikipedia. (2018). Diethyl ether. Recovered from: en.wikipedia.org
7. Safety sheet XI: ethyl ether.. Recovered from: quimica.unam.mx