Common Organic Functional Groups
The essential organic functional groups with their general formulas, naming conventions, and representative examples. Fundamental to understanding organic chemistry nomenclature.
| Functional Group | General Formula | IUPAC Suffix/Prefix | Example | Formula |
|---|---|---|---|---|
| Alkane | CₙH2ₙ+2 | -ane | Ethane | C2H6 |
| Alkene | CₙH2ₙ | -ene | Ethene (ethylene) | C2H4 |
| Alkyne | CₙH2ₙ-2 | -yne | Ethyne (acetylene) | C2H2 |
| Alcohol | R–OH | -ol | Ethanol | C2H5OH |
| Aldehyde | R–CHO | -al | Ethanal (acetaldehyde) | CH3CHO |
| Ketone | R–CO–R' | -one | Propanone (acetone) | CH3COCH3 |
| Carboxylic acid | R–COOH | -oic acid | Ethanoic acid (acetic acid) | CH3COOH |
| Ester | R–COO–R' | -oate | Ethyl ethanoate | CH3COOC2H5 |
| Amine | R–NH2 | -amine | Methylamine | CH3NH2 |
| Amide | R–CONH2 | -amide | Ethanamide (acetamide) | CH3CONH2 |
| Ether | R–O–R' | prefix: alkoxy- | Diethyl ether | C2H5OC2H5 |
| Haloalkane | R–X (X = F, Cl, Br, I) | prefix: halo- | Chloromethane | CH3Cl |
| Thiol | R–SH | -thiol | Ethanethiol | C2H5SH |
| Nitrile | R–C≡N | -nitrile | Ethanenitrile (acetonitrile) | CH3CN |
Important Notes
- R represents any alkyl group (hydrocarbon chain). R' represents a second, possibly different alkyl group.
- IUPAC priority order (highest to lowest): carboxylic acid > ester > amide > aldehyde > ketone > alcohol > amine > alkene > alkyne > alkane.
- The highest-priority group determines the suffix; lower-priority groups are named as prefixes.
- Aldehydes always occur at the end of a carbon chain (terminal); ketones occur within the chain (internal).
- Common names are shown in parentheses. IUPAC names should be used for formal nomenclature.
- Naming follows IUPAC 2013 Recommendations for the Nomenclature of Organic Chemistry.