Talk:Mod:LS1109crashbangwallopwhatavideo

Cope Rearrangement

Presentation:

Data all clearly tabulated. Excellent use of images and diagrams. Jmol used throughout. Appropriate use of file sharing. Animations assist report very well. All tables and images given appropriate legends.

Results:

Investigated a number of anti and gauche conformers - Gauche 3 correctly noted as lowest energy conformer according to the HF method. Frequency analysis carried out for anti 2 isomer- included IR spectra and thermochemical data. Thermochemical data also provided for a number of the lowest energy conformers at 0K – fantastic extra work. Also investigated how the thermochemical data varies with temperature – excellent!

Chair/boat TS – results good. IRC calculations carried out for both chair and boat using a number of methods. Activation energies calculated for both boat and chair at both levels of theory, at 0K and 298K – v.good. These results are then compared to the literature values.

Understanding:

Excellent introduction to report. Nice use of conclusion, and mini-conclusions in between. Steps taken very clear, as are the reasonings why. Good analysis of the results obtained. Rationalises lowest energy conformers well using vdW interactions, MOs, hyperconjugation – excellent! And good comparison to literature. Good understanding of the thermochemical data and what it represents. Student goes beyond what is asked of them and carries out some extremely interesting extra work. Mention in mini conclusion ‘AM1 level of theory’ – however I believe this is just a slip up as earlier you mention you use HF.

Diels Alder:

Presentation:

As above.

Results:

MOs for reactants good and correct symmetries noted. Optimised the TS state using 2 different levels of theory. Correctly noted C-C bond forming distance is < 2 x vdW radius of C suggesting bond forming. HOMO/LUMO interactions explained well. For TS HOMO from 6-31g* study, you’ve noted as antisymmetric, but this isn’t what the image shows – accidentally put in wrong image?

Endo/exo: MOs for reactants and TS good – correct symmetry assigned. Correctly noted endo is lower in energy. Analysis of secondary orbital overlap very good – applied to results. Student has also carried out additional work doing IRC calculations

Understanding:

V. good introduction and conclusion again. Appropriate references to primary literature. Steps taken clear and again well explained. Results analysed well : Good explanation of HOMO/LUMO interactions, could expand a bit on allowed/forbidden reactions. Good explanation of secondary orbital overlap vs. steric effects. Kinetic and thermodynamics control considered. Student also suggests improvements for this study, by using a higher level of theory ( and correctly noting the computational expense associated with this).

Overall this report was excellent. The results were analysed very well and the use of additional work has really enhanced this report.