Question

Explain +R effect by using aniline as example.

Answer 1

Explanation:

The -NH2 group in aniline also exhibits +R effect. It releases electrons towards benzene ring through delocalization. As a result, the electron density on benzene ring increases particularly at ortho and para positions. Thus aniline activates the ring towards electrophilic substitution.

Answer 2

Answer:

If the substitute group has a lone pair of electrons to donate the attached pi bond or conjugate system of Pi bonds the effect is called + R effect. Group such as -OH,-OR,-O(-ve),-NHR,-halogen,etc. having lone pair of electrons show +R effect. The +R effect increases electron density at certain position in a molecule. Figure shows how the +R effect in aniline increases the electron density at Ortho and para position.