Talk:Mod3:BMWWiki

Cope Rearrangement:

Presentation:

Data generally tabulated (TS state section could be made clearer). Good use of Jmol. Animations of negative vibrations v.good. Appropriate use of file-sharing.

Results:

Optimised both anti and gauche conformers, correctly noted gauche 3 as lowest energy isomer. Reoptimised a number of isomers using B3LYP to show gauche 3 is not the lowest energy isomer at a higher level of theory – v.good. More reasoning for why certain conformers may be lower in energy e.g. using vdW interactions, MOs etc. to explain would enhance report. Frequency analysis for anti 2 v. good – included IR spectra and thermochemical data for 298K and 0K.

Chair/Boat TS: Results generally good and TSs found. Investigated using the QST3 method as additional work – v.good. IRC calculatations carried out for chair AND boat! Activation energy table a little confusing, but calculated for both chair and boat TSs using both levels of theory at 0K and 298K, using both anti 1 and anti 2 as reactant – v.thorough. Is the activation energy for the boat TS at 0K missing?

Understanding:

Good concise introduction and conclusion. Steps taken clear and well understood. Good understanding of the levels of theory/methods used and why. A lot of individual thought has been put into this work – well done.

Diels Alder:

Presentation:

As above.

Results:

MOs of reactants and TS good and correct symmetry noted. Good explanation of HOMO/LUMO interactions. Good analysis of C-C bond distances. Could have noted C-C bond forming distance is < 2 x vdW radius suggesting a bond is forming/showing shared electron density.

Endo/exo: Thorough investigation of TSs. Correctly noted endo lower in energy. Good analysis of the MOs. As additional work has carried out IRC calculations and calculated activation energies! Has also taken into consideration kinetic and thermodynamic control of the reaction – excellent! Good consideration of secondary orbital overlap (why do you think this is apparent in LUMO+1? Unsure what is meant by ‘IRC also shows endo to be the most thermodynamically stable product, when exo should be’

Understanding:

Could do with a brief introduction, but very good conclusion. Good analysis of results. Clear explanation of HOMO/LUMO interactions and allowed/forbidden reactions. As well as making improvements to the script, student has also suggested further improvements including using higher levels of theory.

Student has clearly carried out lots of extra work significantly improving the investigation – Well done!