An alkyl group is a functional group of an organic chemical that contains only carbon and hydrogen atoms, which are arranged in a chain. It is formed by removing one hydrogen from the alkane chain and is described by the formula CnH2n+1/03%3A_Organic_Compounds-_Alkanes_and_Their_Stereochemistry/3.03%3A_Alkyl_Groups). The removal of this hydrogen results in a stem change from -ane to -yl to indicate an alkyl group. For example, the removal of a hydrogen from methane, CH4, creates a methyl group -CH3/03%3A_Organic_Compounds-_Alkanes_and_Their_Stereochemistry/3.03%3A_Alkyl_Groups). Alkyl groups are typically a part of a larger molecule and are not found on their own.
Examples of alkyl groups include:
- Methyl group (-CH3)
- Ethyl group (-C2H5)
- Propyl group (-C3H7)
- Butyl group (-C4H9)
- Pentyl group (-C5H11)
- Cyclopropyl group (-C3H5)
- Cyclohexyl group (-C6H11)
Alkyl groups can be classified as primary, secondary, tertiary, or quaternary based on the number of carbon atoms attached to the carbon atom that is attached to the rest of the molecule/03%3A_Organic_Compounds-_Alkanes_and_Their_Stereochemistry/3.03%3A_Alkyl_Groups). The classification is as follows:
- Primary carbon: attached to one other carbon atom
- Secondary carbon: attached to two other carbon atoms
- Tertiary carbon: attached to three other carbon atoms
- Quaternary carbon: attached to four carbon atoms
Alkyl groups are important in organic chemistry and are used in many chemical reactions. For example, alkyl groups can be used as reagents in the synthesis of other organic compounds.
