Question. Draw all possible resonance structures for the following cation and indicate which structure makes the largest contribution to the resonance hybrid.

The group of Lewis contributing structures that represents all possible bond and charge shifts in a compound is known as the resonance structures.

The compound has a ‘three allyl system’, so that pi-electrons shift forming a new carbocation in which there is an electronegative atom with a lone pair of electrons.

The lone pair shifts forming a resonance structure with more number of bonds and less charge separation.

Possible resonance structures of the given cation

The resonance structure that best resembles the resonance hybrids in terms of bonds and charges separation is known as the major contributor of resonance hybrid.

The main contributor of resonance of the given cation is the one with the highest number of bonds and least charge separation

The major contributor of resonance