Talk:Mod:dk27102

Introduction No general introduction.

Cope rearrangement All conformers were successfully identified. Short discussion about their relative energy. (6-31G* basis used from checking the log file, but 6-31G with no polarisation written in the text). Frequency calculation correctly interpreted in term of checking an optimized structure is a minima or a TS. What is the other aim of doing a frequency calculation? It is necessary to get the thermochemistry analysis. Chair and Boat structures successfully identified with the different methods proposed. IRC calculation successfully done and interpreted. Good conclusion about the preferred mechanism, but little discussion overall.

Diels-Alder The explanation of symmetry is correct. Construction of TS MO from fragments could be explained with the use of a correlation diagram. Table “Imaginary Frequencies of Endo & Exo Transition States” is a little misleading as it suggests products have an imaginary frequency associated with them. Dispersion would not change secondary orbital interactions with are pi-pi type. As it happens standard AM1 or PM6 does not have dispersion either. To model dispersion you would have to use MP2 (perturbation theory applied to HF wavefunction) or a dispersion corrected functional (e.g. B3LYP-D). Is there literature to support your ideas of absence of secondary orbital overlap? (http://pubs.acs.org/doi/abs/10.1021/ar0000152).