ABSTRACT
Electrophilicity [1] is the property of being electrophilic and a measure of the the relative reactivity of an electrophile. An electrophile is a reagent attracted to electrons that participates in a chemical reaction by accepting electrons to form a bond with the nucleophile. Because electrophiles accept electrons, they are Lewis acids [2] according to the general acid-base theory of Brönsted and Lowry [3,4]. Most electrophiles are positively charged, having an atom which carries a partial positive charge, or does not have an octet of electrons. Qualitatively, as Lewis acidity is measured by relative equilibrium constants, electrophilicity is measured by relative rate constants for reactions of different electrophilic reagents toward a common substrate (usually involving attack at a carbon atom). Closely related to electrophilicity is the concept of nucleophilicity, which is the property of being nucleophilic, the relative reactivity of a nucleophile. A nucleophile is a reagent that forms a chemical bond to its reaction partner (an electrophile) by donating bonding electrons. Because nucleophiles donate electrons, they are by definition Lewis bases. All molecules or ions with a free pair of electrons can act as nucleophiles, although anions are more potent than neutral reagents.
