Electronic structure and dynamics

Dr. Adrian Mulholland

 

The barrier for the Claisen rearrangement of chorismate to prephenate reaction can be calculated as the difference in energy between chorismate and the transition state structure. 

 

Energy of chorismate: -837.247612027 H

Energy of transition state: -837.208675153 H

Barrier to reaction:      0.038936874H

(per molecule)

 

which is equivalent to 102.2 kJ mol-1

 

This compares to an activation free energy (DG) in solution of 101.2 kJ mol-1, so the agreement is good. 

 

(This result was calculated using ‘density-functional theory’). 

 

Next: other contributions to the barrier