Modeling copper(II) ion-water interaction using a reactive force field

PHYS 325

Obaidur Rahaman, ramie@udel.edu, Department of Chemistry and Biochemistry, University of Delaware, 114 Brown Laboratory, Newark, DE 19716, Douglas J. Doren, doren@udel.edu, Dept. of Chemistry & Biochemistry, U of Delaware, Newark, DE 19716, and Adri CT. van Duin, Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA 16802.
A polarizable and reactive force field, ReaxFF, has been parameterized to simulate the copper ion-water interaction. An ab-initio derived training-set of copper-water clusters and copper metal/metal oxide/metal hydroxide condensed phases was used to fit the force field parameters. An MD simulation successfully reproduced the experimentally observed radial distribution function with a six fold copper ion coordination. The detection of tetragonally distorted octahedral geometries confirmed the reproduction of the purely quantum Jahn-Teller distortion. Thermodynamic integration has been performed to estimate the solvation free energies of a copper ion in water. The result is in good agreement with the experimental hydration free energy of a copper ion. The forcefield is under development to extend it to copper-glycine binding and eventually copper-peptide binding free energy calculations which will help in designing more sensitive and selective bio-sensors of metal cations.
 

PHYS Poster Session - Water Mediated Interactions
7:30 PM-10:00 PM, Wednesday, August 20, 2008 Pennsylvania Convention Center -- Hall C, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, August 18, 2008 Pennsylvania Convention Center -- Hall C, Sci-Mix

Division of Physical Chemistry

The 236th ACS National Meeting, Philadelphia, PA, August 17-21, 2008