Hundreds of years ago, the famous scientist of the time, Lulia, who after death was called an alchemist, was able to open an indispensable now diethyl ether. The formula, properties, boiling point, methods of obtaining the substance will be described in detail in this article.
In the 13th century, the famous Spanish scientist Raymond Lully discovered diethyl ether. Its properties were described in 1540 by an equally famous scientific figure Paracelsus. In 1846, the ether was first used as an anesthetic. The operation carried out by the American physician D. Warren using the vapors of this substance was successful. Inventors of anesthesia consider the dentist W. Morton and his mentor - the doctor and chemist C. Jackson.
The methods of obtaining the ether in the 16th century were described by Valerius Cordus, a famous botanist and a pharmacist from Kassel. Since the beginning of the 18th century, the alcohol-ethereal mixture was used as a sedative - this was the proposal of Friedrich Hoffmann. Petersburg pharmacist Thomas Lovitz in 1796 received pure diethyl ether, the formula of which, incidentally, has two options (more on this later). But the principle of the action of the substance on the human body was published by the English physicist M. Faraday, after which in 1818 a scientific article devoted to this topic was published.
What is called ether? It is an organic compound, whose molecules consist of two hydrocarbon radicals and an oxygen atom. The most important is simple, diethyl ether, the formula of which has the following form:
It is a colorless, transparent, highly mobile volatile liquid, which has a peculiar smell and burning taste.
Under the influence of light, air, heat and moisture, the ether is able to decompose, forming toxic aldehydes, peroxides and ketones, which irritate the respiratory tract.
At a water temperature of 20 degrees, it dissolves by 6.5%. It mixes well with fatty and essential oils, benzene and alcohol, regardless of the ratio.
The ether itself, however, like its vapor, is easily ignited. In a certain proportion with oxygen or air, the diethyl ether pairs used for anesthesia are explosive.
Diethyl ether is characterized by all the chemical properties of ethers. So, we will deal with this issue in more detail. It is quite an inert substance. The main difference from esters is the lack of hydrolysis, however, there are exceptions. In the cold, it does not react with phosphorus chloride, metallic sodium, and many dilute mineral acids. In spite of this, concentrated acids (sulfuric and hydroiodic) even decompose these esters even at low temperatures, and the heated sodium metal splits them.
Ether with unshared electron pairs interacts with a proton of a strong acid, resulting in an unstable oxonium compound:
- Acidolysis. Sulfuric and hydroiodic acids, as well as FeCl3 in acetic anhydride, can decompose ethers. The chemical reaction is as follows: CH3-CH2-O-CH2-CH3 + HJ → CH3-CH2-OH + J-CH2-CH3.
- The reaction of metalation, called the reaction Shorygin. Heated metallic sodium cleaves diethyl ether: C2H5-O-C2H5 + 2Na → C2H5ONa + C2H5Na
- Relative chemical inertness does not prevent ethers from forming peroxides when stored in air, which often leads to explosions at the end of the distillation.
Diethyl ether: physical properties
The peculiar odor, low boiling point of ethers is evidence of a weak intermolecular effect, and this indicates a low polarity and the absence of prerequisites for the formation of hydrogen bonds. In contrast to alcohols, esters have stronger electron-donating properties, which is confirmed by the value of ionization potentials. The enhancement of these features is due to the positive inductive effect of the group of atoms obtained from alkanes upon removal of the hydrogen atom.
Ether - a low-active compound, at times less reactive than alcohols. Remarkably dissolves most of the organic matter, due to which it is used as a solvent. Diethyl ether is not an exception. Physical properties, as well as chemical properties, allow it to be used in medicine and production.
Preparation of diethyl ether
Ethers are not found in nature - they are obtained in a synthetic way. Under the influence of acid catalysts on ethyl alcohol at elevated temperature, diethyl ether is obtained (the formula is indicated above). The simplest way to get this substance is by distilling a mixture consisting of sulfuric acid and alcohol. To do this, it needs to be heated to 140-150 degrees Celsius. We will need ethyl alcohol and sulfuric acid (in equal proportions), pipettes, test tubes and gas pipes.
So, after the equipment and reagents are prepared, you can begin to conduct the experiment. In a test tube (it must necessarily be dry), it is necessary to pour 2-3 ml of a mixture of alcohol and acid and slowly heat. As soon as the boiling starts, the burner is removed, and 5 to 10 drops of ethyl alcohol are added to the hot mixture by means of a pipette along the wall of the tube. The current reaction is as follows:
- CH3-CH2-OH (ethylsulfuric acid) + H2S04 CH3-CH2-OSO3H + H2O;
- CH3-CH2-OSO3H + CH3-CH3-O;
- CH3-CH2-O-CH2-CH3 (diethyl ether) + H2SO4.
The formation of diethyl ether is evidenced by the smell that has appeared.
Use in medicine
Diethyl ether is used as a medicine for the general anesthetic action of the physicians. The properties of this substance do not allow it to be used in operations where electric tools are used, since it is easily ignited, and can explode when connected to air. Diethyl ether is widely distributed in surgery, where it is used for inhalation anesthesia. In dentistry, they process the dental root canals and carious spaces, thus preparing the oral cavity for sealing.
Diethyl ether as fuel
The substance has a high cetane number (85-96), so it can be used as a starting fluid for gasoline and diesel engines. Due to high variability and low flash point diethyl ether is used as a component of the fuel mixture for exemplary diesel engines. It turns out that this substance is similar to ethanol.
Diethyl ether is recommended to be stored in dark-colored bottles (carefully clogged) in a cool place, as it decomposes in the light, in heat and under the influence of moisture, resulting in the release of toxic substances.