Talk:Mod:lkb110mod3

Introduction

Short introduction.

Cope rearrangement

Successful optimisations of the different conformers at the low level. Good idea to reoptimise the 3 lowest conformers with a higher level method. Be careful: energies are negative so Egauche3(B3LYP)=234.57046507 > Eanti1(B3LYP)=234.57119837 ! So you actually managed to reproduce experimental energy differences. Good interpretation of the frequency calculation. TS optimisations successful using the different methods but you could have presented the different methods used, their advantages/drawbacks. Good interpretation of the IRC calculations and good conclusion about the preferred mechanism. Any comments about the agreement between computed activation energies and the experimental values?

Diels-Alder cycloaddition

The important distance is if the forming bond distance is less than twice the vdWs radius as this indicates the two electron clouds are interacting. If the distance is greater than a CC bond length then we expect the structure is half way between reactant and product, i.e. a TS. The lowest real frequency is symmetry breaking, suggesting that this motion is uphill in energy (and would not occur). Can you label the SOO interactions in the computed MO diagrams? Extra discussion on this: <http://pubs.acs.org/doi/abs/10.1021/ar0000152>