Naming Alkynes

Definition of Alkynes:

Names of Alkynes in General

Alkynes are named according to the same system as other organic compounds, with the suffix -yne used to designate the presence in the molecule of a triple carbon-carbon bond.

The first step is to consider the number of carbon atoms forming a chain. If they are attached together in a linear (i.e. unbranched) configuration then the number of carbon atoms is indicated according to the same system as used for naming alkanes. See the examples listed in the table below.

However, if the carbon atoms do not form a linear chain but include branches, the longest linear chain of carbon atoms within the molecule determines the base of the name of the compound, onto which is added information about the branches incl. their lengths in terms of the number of carbon atoms in each branch (i.e. methyl- indicates a branch consisting of just one carbon atom attached to the main chain, ethyl- indicates a branch of two carbon atoms in length, etc.) and their positions along the longest linear carbon chain (e.g. attached to the 2nd carbon, 3rd carbon, etc.).

The simplest linear alkynes are named and their structures shown in the following table.

Names and Structures of simple Linear Alkynes

The homologous series of linear alkynes with the triple bond attached to the first (= last) carbon atom is shown below.

Why stop at ten carbon atoms (in the chain) ? It doesn't ... there are more similar alkynes. We stopped here due to page width.

Important Note: *The synonyms indicated for compounds listed above are just some examples of alternative names found online and believed to have been used to refer to the substance indicated. They have not all been verified and may include common (non-scientific) names, trade names specific to particular suppliers, and perhaps errors. The purpose of these lists is to give a general indication of the range of names by which alkynes are known.

See also the related page about functional groups in organic molecules, which includes the nitrile group among others.

Note: This is one of many pages about types of organic compounds in our Organic Chemistry Section. Similar and related pages describe hydrocarbons, alkanes, haloalkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons (arenes), alcohols, esters, ethers, aldehydes, ketones, carboxylic acids, acid chlorides, acid anhydrides, azo dyes, amines, amides, nitriles, amino acids (chemistry), peptides, proteins (chemistry), polypeptides and others. If you need further information ask your chemistry tutor.