THE DOUBLE-WELL CAGE EFFECT FOR A FERROCYANIDE DIMETHYLVIOLOGEN ION-PAIR IN VISCOUS MEDIA - KINETIC AND THERMODYNAMIC PROBINGS THROUGH THE CT TRANSITION BAND/

The ion pair recombination kinetics following the electric field induc ed predissociation, and the ion pair formation kinetics following dire ct mixing, were studied by temperature jump and stopped-flow technique s, respectively, in viscous water/glycerol mixtures. The rate constant detected for the recombination process was virtually independent of t he glycerol concentration within 65-80% v/v, while direct mixing revea led viscosity-sensitive dispersive kinetics. Thermodynamic parameters for the ion pair formation pseudo-equilibrium under the high viscosity conditions were also determined, which, together with the kinetic dat a, point to at least a two-step mechanism for the ion pair formation. (C) 1998 Elsevier Science B.V.