Sidegrupper

Sidegrupper is a term used in organic chemistry, often in Scandinavian languages, to describe substituent groups that are attached to a core molecular framework. A sidegruppe is not part of the principal skeleton but it modifies the molecule’s properties and behavior. Common examples include alkyl groups such as methyl and ethyl, aryl groups such as phenyl, and functional groups such as halogens (fluoro, chloro), hydroxyl (–OH), carbonyl (–C=O), amino (–NH2), and nitro (–NO2). These groups may occur singly or in combinations and can be located at various positions on the main chain or ring.

In naming and analysis, sidegrupper are treated as substituents and are described with prefixes in systematic nomenclature. They can influence reactivity, guiding reaction pathways and regioselectivity. Some sidegrupper activate or deactivate certain reactions, and they can affect stereochemistry when present on chiral centers. Substituent effects are often discussed in terms of electronic (inductive and resonance) and steric influences.

The presence and nature of sidegrupper affect physical properties such as solubility, boiling and melting points, and chemical stability. In polymers and materials science, side chains or side groups on the main polymer backbone can alter properties like glass transition temperature, crystallinity, and processability. In biochemistry, the side chains of amino acids (the R groups) determine polarity, charge, and how proteins fold and interact.

See also Substituent, Functional group, Nomenclature.