Alcohols, Phenols, and Ethers

Alcohol, phenol, and ether are organic compounds that have various uses and are used in many industries and for domestic use. When saturated carbon bonds with hydroxyl, alcohols are formed. When a hydrogen atom gets replaced by a benzene molecule, then a phenol is formed, and another is formed when an oxygen atom reacts with alkyl or aryl compounds. Examples include ethyl, methyl, and butyl alcohols.

Types of Alcohol

There are three types of alcohol.

1. Monohydric alcohols. e.g., ethanol, propanol, etc
2. Dihydric alcohol. e.g., ethanediol, propanediol, etc
3. Trihydric alcohols. e.g., propanetriol, butanediol, etc
4. Monohydric alcohols have one molecule of OH, whereas
5. Dihydric alcohols have two OH groups.
6. Trihydric alcohols have three OH groups.

Classification of Alcohol

Based on the number of carbon atoms that bond with the the-OH group, alcohol can also be classified into three groups.

• In primary alcohols, the carbon atom with a hydroxyl group is attached to one alkyl group. Examples are methyl, propanol, and butanol.
• In secondary alcohols, the carbon atom with a hydroxyl group is attached to two alkyl groups. Examples include butanol.
• In tertiary alcohols, the carbon atom with a hydroxyl group is attached to three alkyl groups. Examples are methyl and propanol.

Alcohol Usage

• Ethanol is sold with a small amount of methanol as “denatured alcohol” for many industrial uses.

• Ethanol is commonly used as a dissolvent for organic compounds.

• It is used in the fragrance and cosmetics industries.

• Igniting ethanol produces energy, carbon dioxide, and water and can be used as a combustible alone or in a mixture with gasoline.

• Ethyl alcohol is a significant element in alcoholic beverages such as wine and beer.

• Methanol merges with gas to increase flames.

• Methanol is used as a manufacturing raw material to produce other composites like aldehydes and acids.

The properties of Alcohol

• They have higher boiling points due to hydrogen bonding in alcohol.

• The solubility of alcohol in water depends on the presence of an alkyl group.

• Alcohols react with metals to form an alkoxide.

• Alcohols form ketones when they are oxidised.

Alcohol Nomenclature

In the IUPAC system, alcohols are named by changing the ending alkane name tool. Here are the IUPAC rules for the naming of alcohols:

• The largest consecutive chain of carbon atoms with the OH group is considered a parent—an alkane with an identical number of carbon atoms. The chain is numbered from the end nearest the OH group.

• The number that indicates the position of the OH group is prefixed to the name of the parent hydrocarbon; the ending of the parent alkane is replaced by the suffix-ol.

• If more than one OH group resembles the same molecule (polyhydroxy alcohols), suffixes such as-diol and-triol are used. In these cases, the -e ending of the parent alkane is retained.

Examples of Alcohol

Methanol, ethanol, propanol and butanol are the four most common alcohols. They are also the simplest alcohols.

Phenols

Phenols are those compounds in which the OH group is directly linked to the aromatic circle and are termed “-ArOH.” Phenol is different from alcohol because phenol is a bit acidic in water and reacts with aqueous sodium hydroxide to make sodium products. Examples include C₆H₅OH.

Types of phenol

Based on the number of hydroxyl groups attached to the atom, phenols can be divided into three types.

1. They only have one OH group.

1. Dihydric phenols: They have dual-OH groups.

1. Trihydric phenols: They contain triple-OH groups.

Usage of phenol

• Phenols can be used as disinfectants and antiseptic products.

• Phenols are very useful in the production of food preservatives, polymers, and pharmaceuticals.

• Phenols are found in many biological systems. Phenols are a part of nature. Phenols are found in flavouring agents and vitamins.

Phenol Properties

• Phenols are crystalline. They generally make wet and discoloured crystals.

• They are moderately soluble in water.

• Phenols are acidic, and they can react with metals.

Nomenclature of Phenols

• The simplest form of benzene is phenol. It is the general name and it is also accepted by IUPAC. In the common system and also in the IUPAC system, we name the replaced phenols as the derivatives of phenols.
• In the common system, we indicate the substituent position present on the benzene ring concerning the OH group by adding the prefix, such as ortho (o-) for 1:2, meta (m-) for 1,3 and para (p-) for 1,4.
• In the IUPAC system, Arabic numerals are used to indicate the position of the substituent OH group. The carbon-bearing OH group takes the number 1. The phenols possessing a carbonyl group such as aldehyde, ketonic, carboxyl, or an ester group get their names as hydroxyl derivatives of the parent compound.

Examples of Phenol

Phenol is a chemical compound that is used as a pesticide and also as a pH indicator. Some examples of phenol include ortho phenyl phenol, picric acid (trinitrophenol), and phenolphthalein.

Ethers

Ethers are organic compounds that have a functional group of “O”. The general formula for ether is R-O-R. In comparison, the hydrocarbon group is not the same in all the others.

Types of Ether

The following two types are common for ether based on the type of alkyl or aryl groups combined with the O functional group. The types are:

• Symmetrical or simple ethers: These bond with the same alkyl or aryl groups attached on both sides of the O functional group. Examples are C₂H₅OC₂H₅ also known as diethyl, and CH₃OCH₃, commonly known as dimethyl.

• Unsymmetrical or mixed ethers: They bond with different alkyl or aryl groups on either side of the Functional group. Example: C₂H₅OCH₃ or ethyl methyl, CH₃OC₆H₅ or methyl phenyl.

Use of Ether

• Dimethyl ether is used as a coolant.

• It is also a solvent at low temperatures.

• Due to its high boiling point, vinyl ether acts as a heat transfer medium.

• Methoxybenzene is used in cosmetics and occurs naturally in insect pheromones.

• Diethyl is a very common medical anaesthetic.

• Ethyl is a universal solvent for rubber, resins, and oils.

Properties of Ether

• They have low boiling points.

• Like alcohol, they are also dissolvable in water.

• Their molecules have net dipole bonds.

• Some others go under halogenation.

Nomenclature of Ethers

We get the names of the ethers by adding the two alkyl or aryl groups connected to the oxygen particle as separate words in alphabetical order and adding the word ether. For symmetrical ethers, we use the prefix di before the name. In the IUPAC system, ethers are alkylated alkanes. The ethereal oxygen is taken with the smaller alkyl group and forms part of the alkoxy group. On the other hand, the larger alkyl group is taken to be part of the alkane.

Examples of Ether

Ethoxyethane, Methoxyethane, MTBE, and diphenyl ether can be used as solvents.

Conclusion

Alcohol phenols and ethers are the building blocks for detergents, antiseptics, and fragrances. In order to make alcohol, hydrogen is removed from a hydrocarbon that is either aliphatic or aromatic. The hydrogen is replaced with a –OH group. We learned about the various types of alcohol phenol and ether. We also learned about their properties, nomenclature, and applications of alcohol, phenol and ether in this article