Electrofilicity

Electrofilicity is a chemical concept that describes the tendency of a chemical species to attract and react with electrons. The term "electrophile" is derived from Greek words meaning "electron-loving." Electrophiles are electron-deficient species that seek out regions of high electron density in other molecules. Common electrophiles include positively charged ions, neutral molecules with a polarized bond where one atom has a partial positive charge, and molecules with incomplete octets. Examples include the proton (H+), carbocations, Lewis acids like BF3, and halogens like Cl2. The strength of an electrophile is often related to its reactivity in a particular reaction. Reactions involving electrophiles are fundamental to organic chemistry, such as electrophilic addition to alkenes and electrophilic aromatic substitution. The electron-withdrawing nature of atoms or groups within a molecule can increase its electrofilicity. Conversely, electron-donating groups tend to decrease electrofilicity. Understanding electrofilicity is crucial for predicting reaction pathways and designing synthetic strategies.