This Account presents a theoretical formulation for proton-coupled electron transfer reactions. The active electrons and transferring protons are treated quantum mechanically, and the free energy surfaces are obtained as functions of collective solvent coordinates corresponding to the proton and electron transfer reactions. Rate expressions have been derived in the relevant limits, and methodol...

This review is focused on reactions that gate (control) the electron transfer between the primary quinone Q(A) and secondary quinone Q(B) in the photosynthetic reaction centre of Rhodobacter sphaeroides. The results on electron and proton transfer are discussed in relation to structural information and to the steered molecular dynamics simulations of the Q(B) ring flip in its binding pocket. De...

Femtosecond spectroscopy was used in combination with site-directed mutagenesis to study the influence of tyrosine M210 (YM210) on the primary electron transfer in the reaction center of Rhodobacter sphaeroides. The exchange of YM210 to phenylalanine caused the time constant of primary electron transfer to increase from 3.5 +/- 0.4 ps to 16 +/- 6 ps while the exchange to leucine increased the t...

Functional quantum dot (QD)-based nanostructures are often constructed through the self-assembly of QDs with binding partners (molecules or other nanoparticles), a process that leads to a statistical distribution of the number of binding partners. Using single QD fluorescence spectroscopy, we probe this distribution and its effect on the function (electron-transfer dynamics) in QD-C60 complexes...

A theoretical calculation was performed to evaluate the photo-induced electron transfer (PIET) rate between a gold atom and a gold ion solvated in carbon tetrachloride (CCl4) in the framework of Marcus electron transfer (ET) theory, including both solvent reorganization effects and electronic wavefunction coupling between the ET diabatic states. A novel component of this work involves calculati...

The effect of an applied electric field on the kinetics of the initial picosecond electron-transfer reaction in Rb. sphaeroides reaction centers has been measured in isotropic samples at 77 K. The net rate of formation of HL*is reduced upon application of an electric field of IO6 V/cm, consistent with the previously observed increase in the quantum yield of the competing prompt fluorescence. Th...