Adducts

An adduct is a compound formed from two or more chemical species that join together to become a single new molecule, with all atoms of the constituents incorporated. Adduct formation can arise from direct chemical addition, association, or complex formation, and the bond between components may be covalent, dative, or non-covalent. Adducts can be reversible or effectively permanent, depending on the reaction conditions and the stability of the interaction.

In organic and inorganic chemistry, adducts often arise as addition products. For example, the addition of HCl to an alkene yields a haloalkane adduct, while Lewis acids and bases can form Lewis acid–base adducts. Adducts also include solvated species, such as hydrates or solvent adducts, where solvent molecules are incorporated into the crystalline or solution structure of a compound.

In analytical chemistry and mass spectrometry, adducts describe non-covalent associations formed during ionization or ion-molecule processes. Common examples include [M+H]+, [M+Na]+, and [M+NH4]+ ions, which are used to identify and quantify analytes.

In biology and toxicology, adducts refer to covalent attachments of reactive chemicals to biomolecules. DNA adducts and protein adducts are studied as markers of exposure to electrophilic compounds and as mediators of mutagenesis or toxicity. Such adducts can influence biomolecule function and are used in pharmacology, toxicology, and environmental health research.

Overall, adducts describe a broad class of species formed by the union of two or more components, with significance across synthesis, analysis, and biomolecular science.