Chapter 14, Problem 14.5P

Interpretation Introduction

Interpretation:

The charge of the MO picture of the allyl radical ${\text{(CH}}_{\text{2}}{\text{ = CH - CH}}_{\text{2}}^{\text{•}}\text{)}$ is to be determined and explained.

Concept introduction:

The overlap of the two atomic orbitals (AOs) results in the formation of two molecular orbitals (MOs), one of which is lower in energy than the original AOs and the other higher in energy than the original AOs. Two paired electrons can occupy the lower energy MO, resulting in pi bond formation. Two types of molecular orbitals are, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). The HOMO–LUMO gap represents the energy difference between the HOMO and LUMO. For a linear system of conjugated p orbitals, all nodal planes in a resulting π MO must be positioned symmetrically about the center of that set of p orbitals.