Question

Which is not an electrophile?
A.$N{O_2}^ + $
B.$C{H_3} - C{H_2}^ + $
C.$PC{l_5}$
D.$C{H_3}^ + $

Answer 1

Hint: Electrophiles are those species which have a need for electrons. They have affinity towards electrons. It is likely that they have a need for electrons. Those species which have ‘love’ for electrons are known as electrophiles.’phile’ means loving.

Complete answer:
 These are electron loving species. They want electrons. Those species which have positive charge generally have affinity towards electrons. If in any molecule, the octet of its atoms are not complete, they will become electrophile. On the other hand, the opposite of electrophile is nucleophile. Electrophilic substitution reactions are very common in aromatic species.

- If we see option (A), there is a positive charge on the nitro group. Positive charges always have affinity towards electrons. That means it would like to gain electrons. That means this is an electrophile.
- In option (B), there is a positive charge again. That means this is also an electrophile.
- In option ( C ), there is no positive charge. It does not need electrons. Here, both phosphorus and chlorine have complete octet. That means this is not an electrophile.
- In option (D), there is a positive charge. This is methyl cation. This means it is also an electrophile.

Hence, we can say that option C is the correct answer.

Note:
Electrophiles and nucleophiles can be distinguished by their unique properties. We have to keep in mind their properties. Nucleophiles have affinity or ‘love’ towards the nucleus. They have negative charge or excess electron density or lone pairs of electrons that can be donated while Electrophile is affinity towards electrons.