Talk:Mod:takasugi

Introduction absent

Cope rearrangement Several conformers optimised - not all of them. A table may have summarized better these results. Good discussion about their relative energy. Some discussions about the results of a frequency calculation were expected. How do you check that the optimised structure is a minimum? The result figure do not replace the interpretation. TS are optimised and you have checked the one imaginary frequency. No IRC calculation? Good comparison between the calculated and experimental results. What about the preferred mechanism?

Diels Alder Your optimized cis-butadiene structure has an imaginary frequency so is technically a TS (you explain this) but you wanted to find a minimum. As it happens this is very small and so would probably disappear if you optimized using a tighter convergence criteria. Your maximum displacement convergence criteria was 0.001800 Angstrom, so geometries can only be computed to within this accuracy, i.e. there is no point comparing bond lengths to the 4th decimal place.What does the transition state vector corresponding to the imaginary mode say about the likely mechanism of [4 + 2] addition (concerted or asynchronous?). There is no secondary orbital overlap effect in butadiene + ethene (that biases one reaction path over another in any case).

Secondary orbital overlap is not really explained and no evidence is used from ab initio calculations to demonstrate it.

Overall Some good diagrams backed up with understanding from FMO theory, would be good to see discussion of how ab initio results agree/ disagree with empirical theories of reactivity in these systems.