A classical molecular dynamics study of a Diels Alder cycloaddition in supercritical water

Molecular dynamics simulations were performed to investigate the Diels Alder cycloaddition of cyclopentadiene and methyl vinyl ketone in high pressure, high temperature water. It was found that the reaction was favoured by high temperatures at 1000 atm due to increasing entropy. Similarly, at 400 atm, the entropy caused both the equilibrium and rate constant to increase to a peak at 698 K before rapidly falling once more with increasing temperature. At a constant temperature of either 598 K or 898 K, increasing pressure resulted in a lowering of the equilibrium constant. This effect was significantly more pronounced for 898 K, caused by less favourable solvation of the products and an increasing amount of work required for reaction.