Substituent

Chemical Compound
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A substituent is an atom or group of atoms that replaces hydrogen atoms on the parent chain of a hydrocarbon. Substituents are a key concept in organic chemistry, as they can significantly alter the chemical properties and reactivity of the molecule.

Types of Substituents

Substituents can be classified based on their chemical structure and the type of atoms involved. Common types include:

• Alkyl substituents: These are groups derived from alkanes by removing one hydrogen atom. Examples include methyl (−CH₃) and ethyl (−C₂H₅).
• Aryl substituents: These are derived from aromatic compounds, such as the phenyl group (−C₆H₅).
• Functional groups: These include groups like hydroxyl (−OH), carboxyl (−COOH), and amino (−NH₂).

Effects of Substituents

Substituents can influence the physical properties, chemical reactivity, and biological activity of molecules. For example:

• The presence of an electron-withdrawing group can increase the acidity of a molecule.
• Electron-donating groups can enhance the nucleophilicity of a molecule.

Nomenclature

In IUPAC nomenclature, substituents are named as prefixes to the name of the parent hydrocarbon. The position of the substituent is indicated by a number, which is assigned according to the lowest locant rule.

See also

• Functional group
• Organic chemistry
• Chemical reactivity

External links

• Original article on WikiMD