Hydroksigruper

Hydroksigruper refers to the hydroxyl functional group in organic chemistry. Each hydroksigrupe consists of an oxygen atom bonded to a hydrogen atom and to the rest of the molecule, giving the moiety –OH. This group is highly polar and can form hydrogen bonds, properties that strongly influence the physical and chemical behavior of compounds containing it.

Hydroksigruper contribute to higher polarity and usually increase solubility in water. They also raise boiling points relative to similarly sized nonpolar compounds, due to extensive hydrogen bonding. The hydrogen attached to oxygen can be weakly acidic: in aliphatic alcohols the pKa is typically around 15–18, whereas phenolic hydroksigruper are more acidic, with pKa values roughly 9–11 because the resulting anion is resonance-stabilized. The presence of hydroksigruper also makes molecules capable of acting as hydrogen-bond donors and acceptors, influencing reactivity and interactions in biological and environmental contexts.

Hydroksigruper occur across a wide range of substances, including alcohols (monohydric and polyhydric), phenols, carbohydrates, and amino acids. They are common sites for chemical transformations: esterification with carboxylic acids forms esters; oxidation can convert primary hydroksigruper first to aldehydes and then to carboxylic acids; conversion to other leaving groups enables substitutions and eliminations under suitable conditions.

In nomenclature, the prefix hydroxy- is used to denote a hydroksigrupe substituent, while the parent compound containing the group as the principal functional group is often named with the suffix -ol (for example, ethanol, phenol). See also hydroxyl group, alcohol, phenol, and polyols.