Nucleofiilien

Nucleofiilien is a term used in chemistry to describe a chemical species that donates an electron pair to form a chemical bond in reaction with an electrophile. The word "nucleophile" literally means "nucleus loving" because it is attracted to positively charged nuclei. Nucleophiles are typically molecules or ions that possess an electron-rich region, often due to the presence of a lone pair of electrons or a pi bond.

Common examples of nucleophiles include anions such as hydroxide (OH-) or cyanide (CN-), and neutral molecules with lone pairs of electrons like ammonia (NH3) or water (H2O). The strength of a nucleophile is determined by factors such as its basicity, polarizability, and the solvent in which it is present. Stronger nucleophiles react more readily and at a faster rate.

Nucleophiles play a crucial role in many organic reactions, most notably in nucleophilic substitution and nucleophilic addition reactions. In nucleophilic substitution, a nucleophile replaces a leaving group on a substrate. In nucleophilic addition, a nucleophile attacks an electrophilic center, typically a carbon atom in a carbonyl group, leading to the formation of a new bond. Understanding nucleophilicity is fundamental to predicting and controlling the outcomes of chemical transformations.