Functional Groups in Organic Chemistry

These are the major functional groups used in organic chemistry, arranged in order of their nomenclature priorities. The table also includes their suffixes if they are the functional group of the molecule, as well as what you would call it if it were a substituent.

Functional group Substituent name Functional group suffix
Radicals . -yl
Anions . -ide
Cations . -ylium
Carboxylic acids carboxy -oic acid
Sulfonic acids sulfo(nyl) -sulfonic acid
Esters R-oxycarbonyl R-...-oate
Acid halides halocarbonyl -yl halide
Amides carbamoyl -amide
Nitriles cyano -nitrile
Aldehydes formyl -al (or -carbaldehyde)
Ketones oxo -one
Alcohols hydroxy -ol
Phenols hydroxy -ol
Thiols sulfanyl -thiol
Amines amino -amine
Ethers R-oxy .
Sulfides R-sulfamyl .


Adapted from "Organic Nomenclature", Traynham, James 1997 (Prentice-Hall, Inc.)