The dipole moments of the given compounds are | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) In compound $A$ ($N,N$-dimethyl-$p$-nitroaniline),the $-N(CH_3)_2$ group and $-NO_2$ group are in the para position. The lone pair on the nitrogen

Vedclass · Accepted Answer

$A = 6.87 \ D, B = 4.11 \ D$

Vedclass · Answer

(A) In compound $A$ ($N,N$-dimethyl-$p$-nitroaniline),the $-N(CH_3)_2$ group and $-NO_2$ group are in the para position. The lone pair on the nitrogen atom can effectively participate in resonance with the benzene ring,leading to a strong charge-transfer interaction with the $-NO_2$ group. This results in a higher dipole moment of $6.87 \ D$.In compound $B$ ($N,N,2,3,5,6$-hexamethyl-$4$-nitroaniline),the presence of four methyl groups at the ortho positions relative to the $-N(CH_3)_2$ group causes significant steric hindrance (Steric Inhibition of Resonance or $SIR$).This $SIR$ forces the $-N(CH_3)_2$ group out of the plane of the benzene ring,which inhibits the resonance of the nitrogen lone pair with the ring.Due to less effective resonance,the charge-transfer interaction is reduced,resulting in a lower dipole moment of $4.11 \ D$.Therefore,the dipole moment of $A$ is $6.87 \ D$ and $B$ is $4.11 \ D$.

The dipole moments of the given compounds are:

Similar Questions

Which compound among the following will have a permanent dipole moment?

Which of the following bonds will have the highest polarity?

For which molecules among the following,the resultant dipole moment $(\mu) \neq 0?$

In which of the following molecules is $\mu$ (observed) found to be greater than $\mu$ (theoretical)?

Which of the following is the correct order of dipole moment for the given molecules?

Vedclass Test Series

Exam Paper Generator

Online Exam Module