open access

https://hdl.handle.net/2115/45146

Nonlinear dynamical effects on reaction rates in thermally fluctuating environments

英語

2010-07-21

Royal Society of Chemistry

Physical Chemistry Chemical Physics

12(27)

7636-7647

A framework to calculate the rate constants of condensed phase chemical reactions of manybody systems is presented without relying on the concept of transition state. The theory is based on a framework we developed recently adopting a multidimensional underdamped Langevin equation in the region of rank-one saddle. The theory provides a reaction coordinate expressed as an analytical nonlinear functional of the position coordinates and velocities of the system (solute), the friction constants, and the random force of the environment (solvent). Up to moderately high temperature, the sign of the reaction coordinate can determine the final destination of the reaction in a thermally fluctuating media, irrespective of what values the other (nonreactive) coordinates may take. In this paper, it is shown that the reaction probability is analytically derived as the probability of the reaction coordinate being positive, and that the integration with the Boltzmann distribution of the initial conditions leads to the exact reaction rate constant when the local equilibrium holds and the quantum effect is negligible. Because of analytical nature of the theory taking into account all nonlinear effects and their combination with fluctuation and dissipation, the theory naturally provides us with the firm mathematical foundation of the origin of the reactivity of the reaction in a fluctuating media.

学術雑誌論文

Accepted Manuscript

Phys. Chem. Chem. Phys., 2010, 12, 7636-7647 - Reproduced by permission of the PCCP Owner Societies

1463-9076