Question

Why is $NO_{2}^{+}$ an electrophile?

Answer 1

There are two types of molecules that take place in the reaction, i.e., electrophiles and nucleophiles. Phile means loving, so electrophiles mean electron loving.

Complete step by step answer:
In electrophile, Phile means loving, so electrophiles mean electron loving, therefore, if the compound has fewer electrons, then it will be electrophile, whereas, nucleophiles mean nucleus loving, if the compound has an excess of electrons then it will be a nucleophile.
So, as the name suggests electrophiles, electron seeking, can be neutral and have a positive charge. As the given compound is $NO_{2}^{+}$, it is a nitronium ion and in the reactions, it is used as electrophile because there are one nitrogen and the oxygen atom in this molecule, so the nitrogen atom is attached with one oxygen atom through a double bond while with another oxygen atom there is a coordinate bond, and the lone pair on the nitrogen atom gets ionized. Due to this ionization, there is a positive charge on the nitrogen and the octet is incomplete. Therefore, to complete its octet, it acts as an electrophile in the reactions.

Note: Some other examples of positive electrophiles are ${{H}^{+}}$, $C{{l}^{+}}$, $N{{O}^{+}}$, carbocation, etc and some examples of neutral electrophiles are $B{{F}_{3}}$, $AlC{{l}_{3}}$, Carbenes, free radicals, etc.