FOKKER-PLANCK INTERPRETATION OF PICOSECOND INTRA-MOLECULAR DYNAMICS IN SOLUTION

The application of the unabbreviated Fokker-Planck equation to the interpretation of conformational relaxation in solution is discussed. The model incorporates a coupling between viscous and inertial effects in addition to thermally induced motion for the description of the rate coefficient for passage over the barrier in a double-minimum potential. With viscous effects evaluated by hydrodynamics, including hydrodynamic interaction, and a conformational potential determined from spectroscopic and computational data, the model successfully interprets the non-linear viscosity/relaxation time dependence observed in 1,1-binaphthyl A criterion is derived for the applicability of the simpler Smoluchowski equation for such a system, showing that this equation is invalid for the binaphthyl conformation change. © 1979.