Functional groups are group of atoms with specific chemical properties that occur within organic molecules and sometimes denoted as “R”. Functional groups are found along the carbon backbone of macromolecules can form chains or rings of carbon atoms. Functional groups can “functionalize” a compound by enabling it to adopt different physical and chemical properties.

Types of common functional groups

The table below summarizes some of the major functional groups in organic chemistry. (The functional groups are highlighted in red)

Class of organic compounds	Skeletal Structures of Compounds and functional groups (red)	Name of Compounds
Alkene		1-hexene
Alkyne		2-butyne
Alkyl halide		Chloromethane
Alcohol		Methanol
Thiol		Ethanethiol
Ether		Diethyl ether (ethoxyethane)
Sulfide		Dimethyl sulfide (methylthiomethane)
Epoxide		Ethylene oxide (oxirane)

This text is adapted fromOpenstax, Chemistry 2e, Section 20: Organic Chemistry.