Sangeetha Pulapaka

Nucleophiles – Literally ʻnucleus-lovingʼ, nucleophiles are atoms that are electron rich and are going to react to decrease their electron density. Nucleophiles have extra electrons and want to give them away. Nucleophiles can be neutral or charged, but tend to have partial or full negative charges, or if neutral will have a lone pair. The general abbreviation for nucleophiles is Nuwhen negative or :Nu when neutral. All Bronsted-Lowry bases and Lewis bases are nucleophiles and all nucleophiles are Bronsted-Lowry and Lewis bases. Nucleophiles donate electrons, Lewis bases donate electrons into an empty orbital, and Bronsted-Lowry bases donate electrons to H+ .Many neutral molecules are both electrophiles and nucleophiles. Any polar bond will tend to act nucleophilic at the more negative side and electrophilic at the more positive side of the dipole. 

Nucleophilic Acids – Acids can be classified as nucleophilic when the counterion is a good nucleophile (e.g. HCl, HBr, HI) or non-nucleophilic when the counterion is not a good nucleophile (e.g. H2SO4, H3PO4, HClO4). While all of these are fairly strong acids the presence or absence of the nucleophile significantly affects their reactivity and kinds of product formed (e.g. HBr tends to do substitution type reactions with an alcohol while H2SO4 tends to do elimination type reactions with the same alcohol).