reaktioryhmä

Reaktioryhmä is a term used in chemistry to describe a group of atoms within a molecule that largely determines its chemical reactivity and the kinds of reactions the molecule can undergo. In Finnish usage, it is closely related to the concept of a functional group in English. Reaktioryhmät are responsible for characteristic reactions, influence properties such as acidity, basicity, polarity, and solubility, and help explain why different compounds behave in similar ways.

Common examples of reaktioryhmät include the hydroxyl group (-OH) found in alcohols, the carbonyl group (C=O) present in aldehydes and ketones, the carboxyl group (-COOH) in carboxylic acids, and the amino group (-NH2) in amines. Other important groups are the nitro group (-NO2), halogen atoms (-F, -Cl, -Br, -I) in halo compounds, the alkoxy group (-OR) in ethers, and acyl groups (-CO-R) in esters and amides. Phosphate groups and other heteroatom-containing groups also serve as reaktioryhmät in various classes of compounds.

In naming and classification, the reaktioryhmä helps determine the parent structure, the suffixes used in IUPAC nomenclature, and the predicted outcomes of reactions. The concept is central in organic chemistry pedagogy in Finland, providing a framework for understanding reactivity patterns, properties, and synthesis across different molecules.

See also: funktionaalinen ryhmä, IUPAC nomenclature, organic chemistry.