Elektrofylle

Elektrofylle is a term used in chemistry to describe a chemical species that is attracted to electron-rich centers. This attraction stems from the fact that elektrofylle are electron-deficient themselves, meaning they possess a partial positive charge or an incomplete valence shell. Consequently, they tend to seek out and form bonds with areas of high electron density in other molecules, often referred to as nucleophiles.

Common examples of elektrofylle include Lewis acids, such as aluminum chloride (AlCl3) and boron trifluoride (BF3), which can accept electron pairs. Carbocations, which are positively charged carbon atoms, and molecules with polar double or triple bonds where one atom carries a significant positive partial charge, like the hydrogen atom in a hydrogen halide (e.g., HCl), also function as elektrofylle. Halogens, such as bromine (Br2) and chlorine (Cl2), can act as elektrofylle in the presence of a Lewis acid catalyst.

The reaction between an elektrofylle and a nucleophile is a fundamental process in organic chemistry, known as electrophilic addition or electrophilic substitution. These reactions are crucial for synthesizing a wide range of organic compounds and are involved in many important chemical transformations, including halogenation, nitration, and Friedel-Crafts alkylation and acylation. The strength and reactivity of an elektrofylle depend on its electron-deficiency and its ability to accept electrons.