Three-dimensional representations of photo-induced electron transfer rates in pyrene-(CH2)n-N,N′-dimethylaniline systems obtained by three electron transfer theories

Abstract

The observed rates of photo-induced electron transfer (ET) from N,N′-dimethylaniline (DMA) to the excited pyrene (Py) in confined systems of pyrene-(CH2)n-N,N′- dimethylaniline (PnD: n=1–3) were studied by molecular dynamic simulation (MD) and three kinds of electron transfer theories. ET parameters contained in Marcus theory (M theory), Bixon and Jortner theory (BJ theory) and Kakitani and Mataga theory (KM theory) were determined so as to fit the calculated fluorescence intensities with those obtained by the observed ET rates, according to a non-linear least squares method. Three-dimensional profiles of logarithm of calculated ET rates depending on two of three ET parameters, R, ɛ0 and −ΔG° were systematically examined with best-fit ET parameters of P1D. Bell shape dependencies of ET rate were predicted on R and on ɛ0, and on −ΔG° as well, by M theory and KM theory. The profiles of logarithm of ET rate calculated by BJ theory exhibited oscillatory dependencies not only on −ΔG°, but also on R and on ɛ0. Relationship between ET state and charge transfer complex was discussed with BJ theory.