Fig. 4. Potential energy diagrams for 3 (a) in cyclohexane and (b) in acetone. The relative energies were calculated at the CAM-B3LYP/6-31+G(d) (N and O), 6-31G(d,p) (migrating H), and 6-31G(d) (all other atoms) levels of theory, and are given in eV relative to the optimized geometry in S₀.