The distance dependence of the electronic coupling for hole transfer in cation radical systems. A comparison with results obtained by the use of Koopmansʹ theorem

The electronic coupling for hole transfer between two double bonds connected by a variety of saturated hydrocarbon bridges was calculated using ΔSCF, ΔDFT (ΔUB3LYP), ΔUMP2 and Koopmansʹ theorem (KT) methods at the HF and DFT (B3LYP) levels. The results suggest that the constructive and destructive interference effects on the strength and the distance decay dependence of the electronic coupling found previously at the KT HF level are still present at the DFT, ΔSCF, ΔDFT and ΔMP2 levels of theory.