Lewis acids

Lewis Acids

A Lewis acid is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. The term was first introduced by the American chemist Gilbert N. Lewis in 1923.

Definition

In the Lewis theory of acid-base reactions, acids and bases are defined by the way they react with each other, which allows for a broader definition than the classical concept of acids and bases. A Lewis acid is defined as a species that accepts a pair of electrons from a Lewis base to form a coordinate covalent bond.

Examples

Common examples of Lewis acids include all metal cations, and electron-deficient molecules such as boron trifluoride (BF3), aluminium trichloride (AlCl3), and hydrogen chloride (HCl).

Applications

Lewis acids have many practical applications. They are used in the production of many important chemicals, including polymers, pharmaceuticals, and dyes. They also play a crucial role in many biological processes, such as enzyme catalysis.

See also

• Bronsted-Lowry acid
• Acid-base reaction theories
• Chemical bonding
• Coordination complex