AM1 TIP3P MOLECULAR-DYNAMICS SIMULATION OF IMIDAZOLE PROTON-RELAY PROCESSES IN AQUEOUS-SOLUTION/

Molecular dynamics simulations using combined AMI and TIP3P potentials have been carried out to analyze the mechanism of a double proton tra nsfer in aqueous solution for the model system NH44-imidazole-NH3 with fixed N-N distances (2.5 Angstrom). The mechanism is shown to be step wise involving a few system configurations in which the protons are mo re or less delocalised. The characteristic time for the proton relay r eaction is of the order of 1-2 ps. (C) 1998 Elsevier Science B.V. All rights reserved.