Comments

Cyclopentadiene 80

Good! A bit of discussion about the angle bending energy for 3 and 4 would have been nice. How do the structures differ? What is the reason for this increase in energy? Also, your title is "The Hydrogenation of Cp dimer" - but in your discussion you don't even describe the molecules or the hydrogenation reaction. This part needs more discussion, mentioning that it's the two hydrogenation products, maybe a bit about the chemistry behind that and which product is preferred in literature.

Taxol 100

Good effort on finding all the different structures.

NMR 80

"For example, the multiplet reported in literature at 5.21 ppm occurs at 5.97 ppm in the calculated spectrum." Well done on seeing that this is a difference that is not neglible. Discussion: Why do you think that is? Different reasons for that could be (not all likely): literature value is wrong, calculational method doesn't apply for this molecule, the lowest energy geometry is different in the solvent system used in literature. Try to discuss a find like that in a bit more detail, by asking questions and making assumptions. You might get to the wrong conclusion (hey, it's science), but a more in-depth discussion will always show that you have thought about possible reasons for this and will improve any report/paper/thesis you write.

You need to explain why there's a difference in 13C NMR. The calculational method doesn't consider the heavy atom effect of the sulphur atoms.

Epoxide 90

Good section. I like you reasoning about the Jacobsen catalyst how one has to be careful of conclusions from the crystal structure data. But you also should discuss how this steric interaction might effect the catalyst.

So, basically you say that one has to be careful when analyzing this data, and there you stop. You could for example assume the lowest energy conformation is the same in solution and discuss how the tBu groups would affect the catalysis. You might reason that the data is not enough to base any theories on, which would be equally good. Just write down your thoughts.

NMR 100

Rotations 70

Averaging the values seems like a very good idea, but it's wrong, I'm afraid.

Also, and very importantly: You can't just go about changing all the signs! a) That might be considered faking data. b) You're saying the optical rotation is the opposite of what is actually reported - which is just a wrong thing to say. I'll try to explain below.

Basically what this section shows you, all the different values show that literature is not always reliable and that it can be difficult to interpret your findings. Some of the literature might be wrong, some might have had a mix of both enantionmers, some might have used a sample that wasn't clean.

The values might be obviously wrong, but it still is data that was gathered and published by someone else and that has on top of that been peer-reviewed by other scientists. You can't go about changing that, no matter how wrong those results are. Especially, when you have no idea about how the experiments were conducted in the first place. The way it usually works, is to run experiments yourself, maybe backed by computations, which conclusively! show you have a right OR value. Then you can say that the rest of the literature is wrong and try to explain why they might have been wrong in the first place. Also, there's no need to make rubbish data any better. If it's rubbish, it's rubbish

Having said all that, one can see all the effort you put into finding all the literature. Also, well done on trying to find an explanation for your findings - it wasn't the right one, but it's good effort nonetheless because you a) tried to explain your findings in the first place, b) made good assumptions (by taking samples with Chloroform only) and c) you're transparent about how you analyzed everything, allowing your reader to understand your reasoning. And this is how science works. So full points on for the discussion part!

TS 100

Excellent work.

QTAIM and NCI 100

Good discussion!