Talk:Mod:ht309mod3
Cope Rearrangement
Presentation:
Data generally tabulated (but TS section have to look through document to find important values). Good use of images/Jmol. Animations for imaginary frequencies good. Files shared where appropriate.
Results:
All anti and gauche conformers investigated – v.thorough. Correctly noted gauche 3 as lowest energy conformer at this level of theory – what reasoning for this could there be? Could consider MOs, vdW interactions etc. All isomers then reoptimised at higher level of theory at noted gauche 3 not lowest energy conformer at higher level of theory – v.good. Frequency analysis for anti 2 does not appear to have been put in.
Chair/boat TS: Results generally good. TSs found. IRC calculations carried out for chair and boat using a number of different methods. Activation energies calculated for chair and boat for both levels of theory at 0K and 298K – v.good.
Understanding:
Good introduction. Steps taken very clear – could explain further why these steps/methods/keywords were used. Good conclusion, showing some individual thought in the calculations.
Diels Alder
Presentation:
Slightly muddled ordering, but otherwise v.good. Data tabulated. Good use of images/Jmol. Animations for imaginary frequencies good. Files shared where appropriate.
Results
MOs of reactants good, correct symmetries assigned and diagrams of orbitals v.useful. MOs of TS good- HOMO/LUMO interactions clearly understood. Also included IRC calculations as additional work .
Endo/exo: Results generally good. TS found and MOs correct. Correctly noted endo lower in energy. Carried our additional work with IRC calculations – good. Discussed secondary orbital overlap – and applied this to results – v.good! Why do you think this effect is apparent in the LUMO+2?
Understanding
Concise introduction, but no conclusion. Steps taken clear – again explanation as to why these steps were taken would be beneficial. Good analysis of results: HOMO/LUMO interactions considered – could also mention allowed/forbidden reactions. Student also mentions thermodynamic and kinetic control – good. You could compare what your results tell you to what is experimentally known. Good understanding of secondary orbital overlap – and have considered this when looking at your results – v.good. Could also consider steric effects for the endo/exo.