Elektrofíli

Elektrofíli are chemical species that are attracted to and react with electron-rich centers. The name comes from "electro-" meaning electron and "phile" meaning loving. In chemical reactions, elektrofíli act as electron acceptors. They are typically positively charged or have a region of partial positive charge, making them susceptible to attack by nucleophiles, which are electron-rich species.

Common examples of elektrofíli include carbocations (carbon atoms with a positive charge), Lewis acids (electron-pair acceptors), and molecules with polar double or triple bonds, such as carbonyl compounds. Halogens like bromine and chlorine can also act as elektrofíli, especially when polarized by a catalyst or another molecule.

Elektrofíli play a crucial role in many organic reactions, most notably electrophilic addition and electrophilic substitution reactions. In electrophilic addition, an elektrophile adds across a double or triple bond, breaking the pi system and forming new sigma bonds. In electrophilic substitution, an elektrophile replaces another atom or group on a molecule, often a hydrogen atom, typically on an aromatic ring. The strength and reactivity of an elektrophile are determined by its electron deficiency and its ability to accept an electron pair.