IUPAC Nomenclature Foundations

IUPAC

International Union of Pure and Applied Chemistry; the organization whose systematic nomenclature system is used to name organic compounds.

IUPAC Nomenclature

A systematic method for naming chemical compounds according to standardized rules established by IUPAC.

Four Parts of an IUPAC Chemical Name

Locant, prefix, parent, and suffix.

Locant

The part of an IUPAC name that indicates where substituents and functional groups are located.

Prefix

The part of an IUPAC name that identifies the substituent groups attached to the parent.

Parent

The part of an IUPAC name that identifies the main portion of the molecule and indicates how many carbon atoms it contains.

Suffix

The part of an IUPAC name that identifies the primary functional group attached to the parent.

Substituent

A group attached to the parent structure that replaces a hydrogen atom and is identified by a prefix in the compound's name.

IUPAC Name Structure

Locant – Prefix – Parent – Suffix

Purpose of the Locant

Answers: Where are the substituents and functional groups?

Purpose of the Prefix

Answers: What are the substituents?

Purpose of the Parent

Answers: How many carbons are in the main part of the molecule?

Purpose of the Suffix

Answers: What is the primary functional group?

Urea

CO(NH₂)₂: A substance isolated from urine

Morphine

C₁₇H₁₉NO₃: An analgesic

Morpheus

The Greek god of dreams and sleep

Acetic acid

Name the primary organic constituent of vinegar

Acetum

Latin word for ‘vinegar’