alkyl group

6.5

A part of a molecule made of carbon and hydrogen atoms with one hydrogen removed

noun
/ˈæl.kɪl ɡruːp/

Specialized

: grupo alquilo

In organic chemistry, methyl is the simplest alkyl group.

Examples

Substituting an alkyl group for a hydrogen atom can increase the compound's hydrophobicity.
The addition of an alkyl group can alter the properties of a molecule.
An alkyl group is essential in organic chemistry.
The alkyl groups in these molecules determine their properties.
In organic chemistry, methyl is the simplest alkyl group.
Substituting an alkyl group for a hydrogen atom can increase the compound's hydrophobicity.
The addition of an alkyl group can alter the properties of a molecule.

Synonyms

alkyl

vsalkyl group

Specialized

1 9.9

A part of a molecule made of carbon and hydrogen in a chain

is the general term for the same fragment rather than a specific technical label

alkyl radical

vsalkyl group

Specialized

7.3

A group of carbon and hydrogen atoms that attaches to a molecule with one free bond

specifies formation by removing one hydrogen atom from a hydrocarbon

Surface Forms

alkyl group singular

alkyl groups plural

Morphology

alkyl + group

The term is compositionally transparent: 'alkyl' names a radical derived from aliphatic hydrocarbons and 'group' denotes a bonded assembly, so together they straightforwardly refer to a chemical group constituted by an alkyl radical. This is a regular nominal composition used in chemical nomenclature (and mirrored across languages), so a learner who knows both constituents can derive the MWE meaning.

Etymology

The noun alkyl group comes from chemistry naming: alkyl was formed from the word 'alcohol' by changing the ending to 'yl' to show a part of a molecule, and group means a small set of atoms. Imagine removing one 'hydrogen' from a carbon chain and leaving a little 'handle' on the rest of the molecule; this tiny 'handle' is the alkyl group, so the term now means 'a small group of atoms attached to a molecule'.