Talk:Mod:IRONLENSE

1.1 Part 1 (26.5/45%)

1.1.1 Formation and Hydrogenation of Cyclopentadiene Dimer (8.5/10%)

i. Well done obtaining the correct energies and also, good discussion about the energies and kinetic control of the reaction. (5/5%)

ii. Again, well done finding the correct conformation. You compare the different energy terms, however once you noticed the angle bending was the term contributing the most to the energy differences and you explained why, you could have compared the structure of your molecules to confirm your statement. (3.5/5%)

1.1.2 Atropisomerism in an Intermediate related to the Synthesis of Taxol (4/10%)

Compound 9 & 10 have a ciclohexane ring, therefore they have more than one possible conformation each. You should have explored this, as the molecules you obtained may not be the most stable conformation. As this is an organic exercise, this mistake is quite significant. (2/5%)

Well done comparing the energy terms and spotting the differences, however as you didn't obtain the correct conformation for compound 9, these observations are not very meaningful. You mentioned that they are less strained than the parent hydrocarbon, it would have been very interesting if you also have obtained the energy of the parent hydrocarbons and compared the energies to test your statement. (2/5%)

1.1.3 Taxol NMR - Spectroscopic Simulation using Quantum Mechanics (14/25%)

As before, there are more than one possible conformations for each compound! As you don´t provide any information about the energy, or the 3D model I don´t know which one you have done here. It would have been very interesting if you had modeled the different conformers and compared the energies. (2/5%)

HNMR: Well done finding literature values and obtaining the spectra. However, obtaining the spectra is not a hard work as you only need the input command provided in the script. The important part of this exercise is to assign the peaks, compare both spectra, provide a statistical comparison with the literature and a reasonable explanation for the differences.

The way you present the data of the spectra is not very informative. You should have compared both your spectra and the literature data perhaps with a table and then do a deviation analysis to spot the most meaningful differences. (6/10%)

CNMR: the same as before. (6/10%)

1.2 Part 2 (36/55%)

1.2.1 The Crystal Structures of the Shi Catalyst and the Jacobsen Catalyst (5/5%)

Good work finding the structures and discussing their features. (5/5%)

1.2.2 The Calculated NMR Properties of the Epoxides (4/5%)

Well done, even though you don´t show an analysis of the deviation of your values from the literature values. But good work spotting the most significant differences and discussing these. (4/5%)

1.2.3 The Assignment of the Absolute Configurations for Alkenes 2 and 4 (21/35%)

OR: Good, you found a lot of references. You have done a good job calculating the OR as you mentioned you obtained very good correlation with the literature values for all the molecules, but for stilbene oxide. (15/15%)

Assign the configuration of the product: well done the calculations for the Shi catalyst. But you could have added a couple of things that would have helped you getting the full mark: i.e. a discussion is missing, you don´t present any literature values, and also you could have explained better how you have calculated the enantiomeric excess. (6/10%)

You should have also done the Jacobsen catalyst calculations, as it´s very straight forwards because you are giving all the energy values!

(0/10%)

1.2.4&5 NCI and QTAIM Analysis for the Transition State (2/6%)

A discussion of both analysis is missing!

1.2.6 New Candidates (2/4%)

Well done finding an alkene to study, however the discussion is very vague!

Comments: You have done a good work, but I believe that you could have obtained a higher mark if you had spent a bit more time writing the report, specially for Part 2, where you don´t present a discussion in a number of questions. In part 1 is a shame you didn´t realize the different conformations that a ciclohexane motif can have, I suggest you to review this as it´s an important feature for the structure of organic compounds.

Total mark: 62.5 %