Question

The strongest ortho- para and strongest meta-directing groups respectively are

• A. $-N{O}_{2}and-N{H}_2$
• B. $-N{H}_{2}and-N{O}_2$
• C. $-N{H}_{2}and-CON{H}_2$
• D. $-Cland-CON{H}_2$

Answer 1

The correct option is B $-N{H}_{2}and-N{O}_2$

$-N{H}_2$ is one of the strongest and powerful ortho/para directing group due to the electron donating ability of $-N{H}_2$. It shows +R effect. Hence it more activating group than others.

$-N{O}_2$ is one of the strongest deactivating group, it reduce the electron density at ortho and para position by -R effect effect. Hence it the strongest meta-directing group than others.

$-Cl$ and $-CON{H}_2$ are weak meta directing group due to -I effect.