Lewis concept

Lewis concept: (electronic concept.) Positively charged ions or neutral species having tendency to accept lone pair of electron are the Lewis acids. While, negatively charged ions or neutral molecules having tendency to donate lone pair of electrons are the Lewis bases. Some examples are,

Lewis Acids: Na⁺, Cl⁺, H₃o⁺, CO₂, SO₃, AlCl₃, BF₃, SnCl₄, ZnCl₂ and Electrophiles.

Lewis Base: CN^-, NO₂^-, R₃N, Cl^-, RNH₂, R-O-R, R-OH, SnCl₂, NH₃ and nucleophiles.