Functional group

A functional group is any one of a number of specific combinations of molecules within an atom. Used mainly in organic chemistry, functional groups are a helpful way to determine the structure and function of a molecule, as functional groups act very similar no matter what molecule they are a part of.[1]

A generic functional group is represented by the letter R in a chemical formula. For instance, CR4 represents a carbon with four of the same functional group bonded to it.

Some functional groups are described in the following table:[1]

Name  |  Description  |  Ending  |  Simple Example

|
|
|

Alkane |  Carbon-carbon single bond  |  -ane |  Ethane (CH3CH3)
Alkene |  Carbon-carbon double bond  |  -ene |  Ethene (CH2CH2)
Alkyne |  Carbon-carbon triple bond  |  -yne |  Ethyne (CHCH)
Arene |  Unsaturated six-carbon ring  |  none  |  Benzene (C6H6)
Halide |  covalantly bonded F, Cl, Br or I |  none  |  Chloroethane (ClCH2CH3)
Alcohol |  Covalantly bonded -OH  |  -ol |  Ethanol (CH3CH2OH)
Ketone |  Double bonded O  |  -one |  Methyl ethyl ketone (CH3(CO)C2H5)
Aldehyde |  Double bonded O attached to a carbon attached to a hydrogen |  -al |  Acetaldehyde (C2H4O)
Ether |  Oxygen bonded to two other carbons  |  ether |  Diethyl ether (CH3CH2OCH2CH3
Ester |  Oxygen double bonded to a carbon which is also bonded to another oxygen |  ester |  Diethyl ester (CH3CH2OOCHCH3
Amine |  -NR2 |  -amine |  Ethylamine (CH3CH2NH2)
Amide |  Double bonded O attached to a carbon attached to a nitrogen  |  -amide |  Ethanamide (CH3CONH2)
Carboxylic acid |  Carbon double bonded to O and bonded to -OH  |  -oic acid |  Ethanoic acid (CH3COOH)
Carbonyl[2] |  Carbon double bonded to Oxygen, C=O  |  \-  |  Forms part of many larger functional groups

## References[edit]

1. ↑ 1.0 1.1 McMurry, John. Organic Chemistry, 6e. Brooks/Cole: 2004.
2. ↑ The Carbonyl Group