Talk:Mod:cr810module3

Introduction short introduction - could be more developed.

Cope rearrangement Some conformers identified - not all of them. Good discussion about their relative energy. You have run a frequency calculation on a conformer geometry. One point of doing was also to check the structure is a minimum on the potential energy surface -> no imaginary frequency ? TS optimised. Good discussion about the different methods used. “visually there was no bond between the central two atoms (C3-C4)”: Gaussview draws lines between atoms according to their distance with a pre-defined view of bond. But if there is no line, it doesn’t mean there is no bond. Good interpretation of the IRC calculation. Good interpretation of the energy difference and conclusion about the preferred mechanism.

Diels Alder You should only have computed the MOs of cis-butadiene and ethylene with either AM1 of HF (or both if you wanted to compare the difference) but not one for one fragment and one for the other, be consistent with the method used. It is easier to understand the discussion if you orientate the orbitals in figures wrt the symmetry element you are discussing. Good to see discussion of literature discussing secondary orbital overlap effects, but would be nice to see fuller discussion of what the secondary orbital effect is (diagram). Hydrogen bonding is accounted for with Hartree Fock, where would the donor and acceptor be in this system?

Overall Some good work, able to compute stationary points on a surface and characterize them using normal mode analysis. Remember ab initio methods do not require knowledge about the molecular connectivity so you should concern yourself with the measured inter-atomic distance, not with the bonding that Gaussview (or any other visualization software) decides to draw based on some arbitrary criteria.