Dynamics of hydrogen bond exchange in carboxylic acid dimers

Abstract

The simultaneous hydrogen bond exchange within carboxylic acid dimers is investigated by ab initio quantum chemical calculations and by computations of nuclear dynamics. A significant lowering of the potential barrier to ∼60 kJ/mol has been achieved by extensive structure optimization. The calculations suggest that the proton motion is coupled to a deformation motion of the frame of heavy nuclei. The flexible model treatment of this cooperative nuclear motion yields low vibrational and tunneling frequencies.