Electrophile vs. Nucleophile (an overview)

•  Electrophile: (literally electron lovers), Electron deficient, affinity towards electron, Lewis acid

•  -Most of them are positively charged, have an atom that carries a partial positive charged or an atom with an incomplete octet.-participates in a chemical reaction by accepting an electron pair in order to bond to a nucleophile

• -They may be:

• 1.Cations like H+, NO+

• 2.Polarized neutral molecules like HCl, alkyl halides, acyl halides and carbonyl compounds

• 3.Polarizable neutral molecules like Cl2, Br2

• 4.Oxidizing agents like organic per acids

• 5.Chemical species that do not satisfy the octet rule like carbenes and radicals

• Some Lewis acids like BH3

• Nucleophile: (literally nucleus lovers), Electron rich, affinity towards nuclei, Lewis bases

• -donates an electron pair to an electrophile to form a chemical bond in a reaction.

• -All molecules or ions with a free pair of electrons or at least one pi bond can act as a nucleophile

• -They may be:

• 1. ions such as Cl- or molecule like NH3

• 2. Carbon nucleophiles: alkyl metal halides (as in Grignard reaction and anion of a terminal alkyne) and Enols (as in condensation reactions like in aldol condensation).

• 3. Oxygen nucleophiles: water (H2O), hydroxide anion, alcohols, alkoxide anions, hydrogen peroxide, and carboxylate anions.

• 4. Sulphur nucleophiles: Hydrogen sulphide and its salts like thiols.

• 5. Nitrogen nucleophiles: ammonia, amines and nitrites.