Theoretical study of electronic and solvent reorganization associated with a charging process of organic compounds. I. Molecular and atomic level description of solvent reorganization

The electronic and solvation structures of N,N-dimethylaniline in acetonitrile are examined by means of the ab initio reference interaction site model self-consistent-field theory coupled with the method to evaluate nonequilibrium solvation free energy developed by Chong [J. Phys. Chem. 99, 10 526 (1995)]. The key quantities characterizing the solvation process-the free-energy profile governing the solvent fluctuations and solvent reorganization-are evaluated from first principles. A new scheme, which enables us to partition solvent reorganization into atomic contributions in the solute molecule, is proposed and used to analyze the process at the atomic level. We found that the linear response approximation holds well and the overall observable lambda(s) is not much affected by solute geometry, while the individual atomic contribution is significantly changed, especially by the wagging motion of the amino group. (C) 2003 American Institute of Physics.