Select the least stble resonating structure in each of the following sets.

Options

A.
B.
C.
D.

Answer

A, C

Explanation

(i). In option (c) two positive charges are nearer, make this structure less stable.
(ii). `CH_(2)=CH-overset(o+)(CH)-overset(ɵ)(CH)-underset("Releasing gp.")(overset(..)(N)H_(2))`
In `-overset(..)(NH_(2))` gp. Nitrogen having 1.p. and increases `e^(-)` density on carbon atom, `(C^(-))`, make it unstable.
(iii).
Electron releasing group increases electron density more on `C^(-)`, make it unstable.