protonerad

Protonerad is the Swedish term for protonated, describing a chemical species that has gained a proton (H+). Protonation is an acid–base process in which a base accepts a proton from an acid, according to Brønsted–Lowry theory. The site and extent of protonation depend on the molecule’s basic centers and the surrounding pH, and are commonly expressed by pKa values of the conjugate acids.

In solution, protonation produces positively charged species such as protonated amines (RNH3+) and protonated carbonyls (oxonium ions). In the gas phase and in mass spectrometry, protonated molecules frequently appear as [M+H]+ ions, formed during electrospray ionization and related techniques.

Protonation affects properties such as solubility, reactivity, and spectroscopic behavior. It can activate substrates in catalytic reactions, influence binding in enzymes and receptors, and cause shifts in NMR and IR spectra due to changes in electron distribution. The equilibrium between protonated and unprotonated forms depends on pH and the pKa of the conjugate acid; strong bases are readily protonated, whereas weak bases require acidic conditions.

Protonation is reversible; deprotonation occurs when the environment becomes less acidic or when the conjugate acid loses the proton. In practical terms, pH control is used to tune protonation states in chemistry, biochemistry, and analytical techniques such as mass spectrometry and chromatography.

The term protonerad is used in Swedish-language chemistry to describe protonated species; in English, protonated is preferred. Related concepts include acid–base chemistry, pH, pKa, and proton affinity.