Chemical Equilibrium Probed by Two-Dimensional IR Spectroscopy: Hydrogen BondDynamics of Methyl Acetate in Water

摘要

The solvation dynamics of methyl acetate in heavy water are analyzed by means of two-dimensional infraredspectroscopy, in conjunction with Car—Parrinello molecular dynamics simulations. The C=O stretching infraredband of methyl acetate in water splits into a doublet as a consequence of the hydrogen bond interaction withthe solvent, which leads to the equilibrium between two solvated species, consisting of one methyl acetatemolecule bonded to one and two water molecules. The structure and dynamics of the water molecules boundto methyl acetate are characterized by means of experiments and simulations, allowing an accurate descriptionof the kinetics of the exchange process and the lifetime of the hydrogen bond.