Figure 9.
Solvent dependence of the association constant (Ka, top panel), the dissociation quantum yield of the exciplex (ϕdiss, center), and the fraction of excited fluorophore quencher pairs deactivating to solvent-separated ions (ϕI, bottom) as opposed to the exciplex. Trend lines have been added to guide the eye. The dissociation quantum yield has been evaluated from the exciplex lifetime under the assumption that for εr = 6 the exciplex does not dissociate and that its radiative and nonradiative rate constants do not change with solvent permittivity in the range accessible by the used solvent mixture (6 ≤ εr ≤ 25). Fitting the dissociation quantum yield ϕdiss did not give rise to significantly altered results for either Ka or ϕI.