Competitive electron transfers in model ionic triad systems: MD simulations

We present the second part of the work [J. Phys. Chem. 100 (1996) 8815] devoted to electron transfer (ET) reactions in model triad systems. A model supramolecule is the ionic triad D+–A1−–A2 immersed in acetonitrile solvent at room temperature. The ET rate constants for both the charge separation (the forward ET) and the charge recombination (the backward ET) are expressed in terms of the two-dimensional (2D) statistical distribution of the respective solvent polarization coordinates. This distribution for the triad with various angular arrangements of the subunits has been evaluated by the MD computer simulation for the molecular model of the solvent. The dependence of the yield of the charge-separated state D+–A1–A2− on the triad geometry and the free energy changes of the forward and the backward ETs as well as the conditions that maximize the yield of the forward ET have been considered.