Simulations of proton transfer reactions in solution

PHYS 448

Jill Zwickl,, Julian Tirado-Rives,, William L. Jorgensen,, and John C. Tully, Department of Chemistry, Yale University, New Haven, CT 06520-8107
Monte Carlo and molecular dynamics simulations have been carried out for proton transfer (PT) reactions in both polar and non-polar solvents. Semiempirical interaction potentials (AM1, PM3, and PDDG/PM3) were employed in order to realistically describe the PT solute molecules. Solvent-solute and solvent-solvent interactions were modeled using classical OPLS potentials. Free energy curves for the PT reactions were generated using a modified version of the Biochemical and Organic Simulation System (BOSS) Monte Carlo program; these curves were used to obtain Marcus theory parameters. Proton transfer rates calculated by Marcus theory will be compared to rates obtained using molecular dynamics with quantum transitions (MDQT) simulations, using the same interaction potentials noted above. Initial studies were based on the symmetric bimolecular PT reaction between trimethyl ammonium ion and trimethyl ammonia in water. Asymmetric and unimolecular PT systems will also be studied.

Poster Session
7:30 PM-10:00 PM, Wednesday, 13 September 2006 Moscone Center -- Hall D, Poster

Division of Physical Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006