Talk:Mod1:yz908

1.2.1 Cp dimers: Your energies are good, nice to see the differences clearly stated for the reader. Your explanation of kinetic vs thermodynamic control is a little shaky. Good to see you relating energy terms to structural features. It’s not usual to give energies in Hartrees (especially to 10 d.p., can you really be sure your calculations are that accurate?). In fact, you give energies in kcal, kJ and Hartrees, pick ONE. If you are quoting other people’s results it is good practice to name them and explain what they did. It is not valid to compare the fully hydrogenated dimer to the either partially hydrogenated dimer as they are not isomers!

1.2.2 NAD: Nicely presented minimisations. Also good to see you thinking about potential improvements to the method of calculations.

1.2.3 Taxol: Your answers are a little vague and circuitous. Try writing more directly and to the point, short sentences allow you to effectively communicate statements, such as answers, to your reader. Still, the analysis is sound.

1.3.1 Carbene: Introductions can sometimes be useful but they’re not really necessary in such length here. Your molecule has a plane of symmetry yet your orbitals are not symmetrical. This is something I would have expected you to pick up on. The problem is caused by a bug in MOPAC PM6. Moral of the story: question the results the computer gives you, learn to identify these errors and how cope with them. Your analysis is fine. I don’t really need to see the IR spectrums. Good analysis.

Mini-project: It is MUCH better practice to number molecules rather than give them names such as ‘H-pointing up’. You cannot state that H-up will have the lowest energy unless you know whether the reaction is under kinetic or thermodynamic control. Good to see you representing your results graphically, however a slightly better way to highlight the accuracy of your calculations would be to graph the differences alone. Those are some incredibly accurate NMR predictions. So do these results allow you to choose between different isomers? Are there any other analytical techniques that would allow you to do this?

Overall: A good attempt, although your English needs some work. In the future, pick only ONE unit of energy to use and quote your answers to fewer d.p.!