hemistry, an electrophile is a chemical SPECIES that forms bonds with nucleophiles by accepting an electron pair.[1] Because electrophiles ACCEPT electrons, they are Lewis acids.[2] Most electrophiles are positively charged, have an atom that carries a partial positive CHARGE, or have an atom that does not have an octet of electrons.Electrophiles mainly interact with nucleophiles through addition and substitution reactions. Frequently seen electrophiles in organic syntheses include cations such as H+ and NO+, polarized neutral molecules such as HCl, alkyl halides, acyl halides, and carbonyl compounds, polarizable neutral molecules such as Cl2 and Br2, oxidizing agents such as organic peracids, chemical species that do not satisfy the octet rule such as CARBENES and radicals, and some Lewis acids such as BH3 and DIBAL.(ii)Nucleophile is a word used to refer to substances that tend to donate electron pairs to electrophiles in order to form chemical bonds with them. Any ion or molecule having an electron pair which is free or a pi bond containing two electrons have the ABILITY to behave like nucleophiles.