Dynamics in ionic solutions - Revisited

We used steady-state absorption, emission, and time-resolved fluorescence measurements of coumarin 153 in butyl acetate-LiClO(4) solutions to study the static and dynamic aspects of ion-probe interactions, We analyzed the low concentration data in terms of two distinct, solvate configurations. The first distinct solvate was a probe molecule surround by II solvent molecules in the first solvation shell; in the second distinct solvate, one of the surrounding solvent molecules was replaced by a Li(+) cation. We used a diffusive model to describe quantitatively the dynamics of the ion/solvent exchange reaction. At low concentration (less than or equal to 0.5 M), our model accounts for steady-state spectroscopic data and the viscosity dependence of the dynamics.