Theoretical study of protic solvents hydrogen bonding effect, on the reaction of cyclopentadiene and vinyl acetate; apart from the bulk properties

Ab initio, DFT, Monte Carlo statistical mechanics and atom in molecule methods have been applied to investigate the hydrogen bonding effect of protic solvents, apart from the bulk properties, on the reaction of cyclopentadiene and vinyl acetate. The results show that methanol accelerates the rate of the reaction more than water. DFT calculations demonstrate that the interaction of the carbonyl group oxygen atom with solvent molecules in transition state is stronger and more effective than the ether-type oxygen atom. Also, when the solvent molecule is near the oxygen of the carbonyl group the rate of reaction is larger than when it is near the ether-type oxygen. In addition, methanol stabilizes the reacting system and increases the reaction rate more than the water molecule. Monte Carlo simulation indicates that the reacting system is preferentially solvated by water molecules in a mixture of water and methanol molecules. Hence, the rate enhancement in the mixture is nearly the same as for pure water. (C) 2009 Elsevier B.V. All rights reserved.