Which of the following compounds will not exist as resonance hybrid. Give reason for your answer.
(a) `CH_(3)OH`
(b) `R - CONH_(2)`
(c) `CH_(3) CH = CHCH_(2)NH_(2)`

Explanation

(a) `CH_(3)OH` As it lacks `pi-`electrons hence it will not exist as resonance hybrid.
(b) `R - CONH_(2)` due to the presence of `n-` electrons on N and `pi-` electrons on `C = O` bond, hence amide can be represented as a resonace hybrid of the following three resonating structures.

(c) `CH_(3)CH = CHCH_(2)NH_(2)` As the one pair of electrons on the N-atom is not conjugated with the `pi-`electrons of the double bond, thus, resonacne is not possible and hence no resonance hybrid will exist.