Activity: Talk or presentation › Poster presentation › Science to science
The physical properties of the solvent influence the rate constant of Photoinduced electron transfer (PET) reactions in many ways. Dielectric constant ε and refractive index n influence the solvent dipole reorientations and contribute to the activation energy of the ET reactions . Electron-transfer kinetics is also influenced by diffusion and therefore by the solvent viscosity η. Unfortunately, most measurements published use different solvents in a not consequent way . We present here the results of experiments made in a series of solvent mixtures comprising propyl acetate (PA), butyronitrile (BN), and diethyl phthalate (DEP), spanning a wide range of dielectric constants, keeping the n and η constant . We used the PET reaction of singlet excited pyrene and indole whose solvent dependence is already described in the literature . Quenching rate constants were obtained from Stern-Volmer plots based on both static and dynamic (TCSPC) measurements. The ΔG-dependence of ln kq are reported for the solvent mixtures and compared with results reported in pure organic solvents .
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