Abstract
The effect of an inert salt on the time-resolved fluorescence from excited hydroxypyrene-trisulfonate is measured and compared quantitatively to the solution of the transient Smoluchowski equation for proton diffusion-reversible recombination in the excited-state. The data in water can be explained by the screening and mobility-diminishing effects of the added salt. In methanol-water mixtures we observe additionally an enhancement of proton dissociation. The microscopic mechanism for proton mobility in water and methanolic mixtures is discussed. Since the rate-limiting step for proton mobility is a hydrogen-bond cleavage, percolation properties of the hydrogen-bond network might lead to a discontinuous drop in proton mobility, possibly reflected in our data.
Original language | English |
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Pages (from-to) | 161-195 |
Number of pages | 35 |
Journal | Journal of Molecular Liquids |
Volume | 64 |
Issue number | 1-2 |
DOIs | |
State | Published - Aug 1995 |