Organic Chemistry: Orbitals

Problems: Molecular Orbital Theory

Problem : Draw MO energy diagrams for the molecular ions H2+ and H2-. Which ion has the stronger H-H bond?

Problem 1
Since both molecular ions have a bond order of 1/2, they are approximately equally stable.

Problem : Surprisingly, the hybridization of the starred oxygen in the following molecule is sp2, not sp3. Account for this observation using your knowledge of extended Π systems.

Problem 2

By adopting an sp2 hybridization, the lone pair in the p orbital can overlap with the adjacent Π bond. This can be illustrated using an orbital picture or with resonance structures:
Figure %: Solution