Talk:Mod:brapbrap

1.1 Good energies for all four compounds. Thermodynamic vs kinetic control is well discussed. Good analysis of the contributions to the energies of the different hydrogenated products.

1.2 Well answered question. The energy values are good and your explanation of the observed stereoselectivity is well reasoned.

1.3 Your energy values and related ideas are good and the definition of hyperstable alkene is well researched. Take care with your jmol images as the CO-up image is labelled as CO-down and vice versa.

1.4 Some of the energies are a little high; it’s possible that the best hydrogen bond was missed. Discussion about the optimisation was good. As you state, for reaction, the distance and angle of approach are important. In spite of the assertions of the report in the literature, it seems possible to get all of the different conformers in a position to react. Therefore, MM2 calculations cannot give the complete story.

1.5 The analysis of the stretching frequencies is done well; as well as the HOMO implying which groups are nucleophilic, the LUMO implies that the exo double bond may react as an electrophile.

MP – It was not necessary to do two mini-projects! Nevertheless, both projects are presented well and some good avenues of investigation are followed. The tabulation of calculated and experimental data is good, but it w have been beneficial to see the differences between the data listed to show how good a match it is.

NB: It is not usual to integrate peaks in a 13C spectrum because the intensity of the peak is dependent on the relaxation time of the nucleus in question which differs depending on the chemical environment; hence quaternary carbon peaks are smaller than others because relaxation of the nuclear spin is slow.