elektrofilowi

Elektrofil, in chemistry, is a species that seeks electrons and forms bonds by accepting an electron pair from a nucleophile. In Polish, the base form of the word is elektrofil, with elektrofilowi being the dative singular form used when the word appears as an indirect object. Electrophiles are typically electron-poor, positively charged, or highly polarizable, and they include protons (H+), carbocations, and various Lewis acids such as BF3, AlCl3, or NO2+.

Electrophiles play a central role in many reaction types. They react with nucleophiles, which donate electron pairs, to form new covalent bonds. Classic examples include electrophilic aromatic substitution, where a benzene ring reacts with a strong electrophile like NO2+ or a sulfonium species, and electrophilic addition to alkenes, such as the addition of Br2 to an alkene. In nitration, the nitrating agent NO2+ electrophilically attacks an aromatic ring, yielding nitro-substituted products.

Reactivity of electrophiles is influenced by factors such as charge, polarity, and polarizability, as well as the stability of any positive charge developed during the reaction transition state. Solvent effects, temperature, and the presence of electron-donating or withdrawing substituents can alter their strength. The concept of electrophiles is often discussed alongside nucleophiles, with reactions proceeding via electron-pair donation from nucleophiles to electrophiles.

See also: nucleophile, Lewis acid, electrophilic aromatic substitution, electrophilic addition.