Talk:Mod:FRC1510
Introduction
Absent.
Cope rearrangement
Few conformers successfully optimised not all of them. Any physical explanation for their relative energy? You should use the frequency calculation results to check whether the structure you optimised is indeed a minimum (only real frequencies). TS optimisations successful using the different methods. Good interpretation of the IRC calculations. Any conclusion about the preferred mechanism? Any comments about the agreement between computed activation energies and the experimental values?
Diel-Alder cycloaddition
How do the forming distances compare to 2x C vdW distance which indicates the limit at which the two electron clouds start interacting? The fact it is shorter than this but longer than the CC equilibrium distance shows the structure is between reactant and product, i.e. a TS. The lowest real frequency is symmetry breaking, suggesting that this motion is uphill in energy (and would not occur). Notice how the (C=O)2C group interacts with the C=C in the endo form. Why might this cause this form to be favoured over the exo (FMO explanation using secondary orbital overlap effects, sterics etc.) Can you see any SOO effects in the orbitals? Extra discussion on this: <http://pubs.acs.org/doi/abs/10.1021/ar0000152>