Talk:Mod:323

Introduction too short

Cope rearrangement Several conformers optimised. Good discussion about their relative energy. Too many figures: the only information that you looked at in the summary table is the energy and the symmetry point group. So you don’t need to show all of them.TS optimised and good interpretation of frequency calculations. You have run the IRC calculation but what do you conclude from it? Which conformers does the TS connect? Good interpretation of the activation energies and about the preferred mechanism.

Diels Alder The orbitals are symmetric/asymmetric wrt the Cs plane (derived from the molecules point group). In your figures this is not coincident with the yz plane. It would be better to depict the cis-butadiene orbitals wrt the symmetry element you are describing. The HOMO for the [4+2] addition TS looks symmetric but is labelled asymmetric. This calculation seems to have been done with B3LYP/6-31G*, you should explain this somewhere. The HOMO computed with AM1 is asymmetric. Maybe a correlation diagram could have been constructed to describe how the MOs are made up from the two fragments. What does the imaginary normal mode suggest about the mechanism (concerted or asynchronous?) As well as the basis set you should give the method used (HF, B3LYP etc.) Use your ab initio MOs to show secondary orbital overlap in a figure.

Overall Demonstrated understanding of how to locate critical points computationally but would have been nice to see a fuller discussion of how these calculations can be used to provide evidence for empirical models, e.g. secondary orbital overlap, Woodward-Hoffmann rules etc.