Adduct: definition in chemistry
Adduct: A single product formed when two or more molecules join directly, with all of their atoms kept. It often forms when one molecule donates a pair of electrons to another.
In a typical adduct, a Lewis base with a lone pair of electrons bonds to a Lewis acid that has room to accept them, forming a coordinate (dative) covalent bond. Nothing is lost in the process, which distinguishes adduct formation from reactions that release a small molecule such as water. Adducts are common in synthesis and biochemistry, where a harmful chemical bound to DNA is called a DNA adduct.
Examples
- Ammonia + boron trifluoride → H₃N–BF₃
- Boron trifluoride etherate, BF₃ bonded to diethyl ether, a common lab reagent
- The ring-shaped product of a Diels–Alder reaction
- Chemicals from tobacco smoke bound to DNA in lung cells
On the periodic table
Boron and aluminum in group 13 often form compounds with only six valence electrons around them, such as BF₃ and AlCl₃, so they readily accept an electron pair to form adducts.