What do Lewis acids do?

Lewis acids are substances that accept electron pairs during chemical reactions. The defining characteristic of a Lewis acid is its ability to function as an electron acceptor, which facilitates the formation of a coordinate covalent bond with a Lewis base, which donates an electron pair. This is fundamental in organic and inorganic chemistry, where understanding the behavior of acids and bases, according to Lewis’s definition, plays a crucial role.

When a Lewis acid accepts an electron pair, it can interact with a variety of substrates leading to new bond formation and the creation of more complex structures. This behavior is distinct from classic Brønsted-Lowry acids that donate protons; instead, Lewis acids broaden the understanding of acid-base chemistry beyond just proton transfer.

The other options, while related to acid-base chemistry, do not accurately describe the actions specific to Lewis acids. For example, donating protons is characteristic of Brønsted acids, donating electrons pertains to Lewis bases, and forming hydrogen bonds is a specific type of interaction that can involve both acids and bases, but does not fundamentally define a Lewis acid.