External electric field to control the Diels-Alder reactions of endohedral fullerene.

The present work investigates the role of External Electric Field (EEF) on a Diels-Alder reaction of endohedral fullerene by means of chemical kinetics and quantum chemical calculations. The investigation suggests that by combining two strategies, first encapsulating the cation inside the fullerene followed by applying EEF, one can easily manipulate the energy barrier of the Diels-Alder reaction. To illustrate this general strategy, we have chosen the reaction of fullerene (C 60 ) and 1,3 cyclohexadiene, which is associated with a high energy barrier height of ∼11.2 kcal mol -1 . Our calculation reveals that this reaction can be turned into a barrierless reaction by applying the EEF oriented along a suitable direction, and at the same time by changing the direction of EEF, the EEF can also act as an inhibitor.