What is "adduct"

Adduct \Ad*duct"\, v. t. [L. adductus, p. p. of adducere. See Adduce.] (Physiol.) To draw towards a common center or a middle line.
--Huxley.

n. (context chemistry English) The product of an addition reaction vb. (senseid en move_midwise)(context transitive physiology English) To draw towards a center or a middle line.

n. a compound formed by an addition reaction

v. draw a limb towards the body; "adduct the thigh muscle" [ant: abduct]

An adduct (from the Latin adductus, "drawn toward" alternatively, a contraction of "addition product") is a product of a direct addition of two or more distinct molecules, resulting in a single reaction product containing all atoms of all components. The resultant is considered a distinct molecular species. Examples include the adduct between hydrogen peroxide and sodium carbonate to give sodium percarbonate, and the addition of sodium bisulfite to an aldehyde to give a sulfonate. It can just be considered as a single product resulting from direct addition of different molecules and constitutes all the reactant molecules' atoms.

Adducts often form between Lewis acids and Lewis bases. A good example is the formation of adducts between the Lewis acid borane and the oxygen atom in the Lewis bases, tetrahydrofuran (THF): BH•O(CH) or diethyl ether: BH•O(CHCH).

3 and THF" widths="100px" heights="100px" perrow="1"> Image:Tetrahydrofuran-3D-balls.png| THF molecule Image:Borane-3D-balls.png| BH molecule Image:Borane-THF-adduct-3D-balls.png|Lewis adduct between BH and THF,

Compounds or mixtures that cannot form an adduct because of steric hindrance are called frustrated Lewis pairs.

Adducts are not necessarily molecular in nature. A good example from solid-state chemistry is the adducts of ethylene or carbon monoxide of CuAlCl. The latter is a solid with an extended lattice structure. Upon formation of the adduct, a new extended phase is formed in which the gas molecules are incorporated (inserted) as ligands of the copper atoms within the structure. This reaction can also be considered a reaction between a base and a Lewis acid with the copper atom in the electron-receiving role and the pi electrons of the gas molecule in the electron-donating role.