In the following sets of resonance forms, label the major and minor contributors and state which structures would be of equal energy. Add any missing important resonance forms.
(d)
(e)

Verified step by step guidance

1. Identify the resonance structures in each set. For set (d), the structures involve a nitro group and a carbanion. For set (e), the structures involve an amine group and a carbocation.
2. Evaluate the stability of each resonance structure. In set (d), the carbanion is more stable when it is adjacent to the electron-withdrawing nitro group, making it a major contributor. In set (e), the resonance structure with the positive charge on the more substituted carbon is more stable.
3. Determine the major and minor contributors. In set (d), the structure with the carbanion next to the nitro group is the major contributor. In set (e), the structure with the positive charge on the more substituted carbon is the major contributor.
4. Check for any missing resonance forms. In set (d), consider if there are any other possible resonance forms involving the movement of electrons. In set (e), consider if there are any other possible resonance forms involving the movement of electrons.
5. State which structures would be of equal energy. In set (d), the two structures are not of equal energy due to the differing stability of the carbanion positions. In set (e), the two structures are not of equal energy due to the differing stability of the carbocation positions.

Key Concepts

Resonance Structures

Resonance structures are different ways of drawing the same molecule that illustrate the delocalization of electrons. They help in understanding the actual electronic structure of a molecule, which is a hybrid of all possible resonance forms. The stability and contribution of each resonance form depend on factors like the octet rule, charge distribution, and the presence of electronegative atoms.

Major and Minor Contributors

In resonance theory, major contributors are the resonance forms that are more stable and thus have a greater influence on the overall structure of the molecule. Minor contributors are less stable forms that contribute less to the resonance hybrid. Factors such as formal charge, octet fulfillment, and the presence of electronegative atoms determine the stability of these contributors.

Equal Energy Structures

Equal energy structures refer to resonance forms that have the same energy level and thus contribute equally to the resonance hybrid. These forms typically have similar stability and do not favor one over the other. Identifying these structures is crucial for understanding the reactivity and properties of the molecule, as they can influence the distribution of electron density.