What are electrophiles? Give one example …

 Electrophiles (Electrophilic reagents): Electrophiles are electron loving chemical species having an atom which is deficient in electrons. There are two types of electrophiles:

(a) Positively charged ions or positive electrophiles: These are deficient in electrons and carry a positive charge. For example H⁺ (hydrogen ion) H₃O⁺(hydronium ion),  (Nitronium ion),


(b) Neutral electrophiles. These are electrophilic reagents in which the electron deficient atom does not carry any charge. For example AlCl₃, FeCl₃, BF₃, SnCl₄. Carbenes also act as electrophiles because the carbon in them has only six electrons. 

Since both positively charged and neutral electrophiles are short by a pair of electrons, they have strong tendency to attract electrons from other sources and hence behave a Lewis acids.
 
Electrophiles always attack the substrate molecule at the point of high electron density.