Question

$p$-nitro - $N,N$ - dimethylaniline cannot be represented by the resonating structures

• A. I and II
• B. II and IV
• C. I and III
• D. III and IV

Answer 1

Answer: (B)

Both the structures are impossible as $N^{\star }$ is pentavalent and we known that $N$ can not expand its valency beyond $4$ due to absence of vacant $d$-orbitals in its valence shell.