Nomenclature of Carbon Compounds

"Nomenclature is the system of assigning a proper name to a particular carbon compound on the basis of certain rules."

Most of the carbon compounds have two types of names:

• Trivial Names
• IUPAC Names

Trivial Names

The trivial names are the commonly used names of carbon compounds. They are derived mostly from the source of the compound e.g., the name of formic acid is derived from 'formicus' the Greek word meaning red ants. Names arrived in this way were ambiguous and repeating.

IUPAC Names

With the large growth of carbon compounds, it was necessary to name these compounds in a more systematic way. A committee called the 'International Union for Pure and Applied Chemistry' (IUPAC) put forward a system of giving proper scientific names to carbon based compounds. The names derived by their rules are the names followed all over the world and in short are called IUPAC names.

In this system the name of a carbon compound has three main parts as mentioned below:

Wood Root

This denotes the number of carbon atoms present in a given molecule. For e.g., C₁-Meth, C₂- Eth, C₃ - Prop, C₄- But.

Suffix

The suffix denotes the type of bonds or the functional group present in the carbon chain, e.g.

Type of bond	Functional group
'ane' (single bond)	'ol' for alcohols (-OH)
'ene' (double bond)	'al' for aldehydes (-CHO)
'yne' (triple bond)	'oic acid' for carboxylic acid (-COOH)

Prefix

This denotes the presence of other functional groups and their position.

For e.g., the following compound can be named as:

Word root: But (C₄)

Prefix: 3, chloro

Suffix: -ol

Name: 3-chloro butanol

Note carbon atoms are numbered from the side of the functional group (-OH in this case).

The IUPAC names along with trivial names and formula of some organic compounds are given in the following table:

Trivial Names, IUPAC Names and Molecular Formula of some Organic Compound

Trivial name	IUPAC names	Formula
Methane	Methane
Ethane	Ethane
Ethylene	Ethene
Acetylene	Ethyne
Formaldehyde	Methanal
Acetaldehyde	Ethanal
Formic acid	Methanoic acid
Acetic acid	Ethanoic acid