Question

Arrange the following resonating structures in order of increasing stability
`underset((I))(CH_(2)=overset(+)(N)=overset(-)(N))" "underset((II))(H_(2)overset(+)(C)=N=overset(-)(N))" "underset((III))(H_(2)overset(-)(C)-overset(+)(N) equiv N)" "underset((IV))(H_(2) overset(-)(C)-N=overset(+)(N))`

Answer 1

The correct order of increasing stability is : `(I) gt (III) gt (II) gt (IV)`
`*" "`Structure `(I)` is maximum stable because conjugation is maintained.
`*" "`Structure `(IV)` is least stable because electronegative carbon atom has negative charge.
`*" "` Out of structures `(II)` and `(III)`, the structure `(III)` is more stable because of the presence of triple bond between the two nitrogen atoms.