Electron binding energy and long‐range electronic coupling: A theoretical study

Electronic couplings in long‐range electron transfer have been calculated using ab initio molecular orbital theory to investigate the effect of the binding energy of the electron on the decay of through‐space and through‐bond couplings. Through‐space and through‐bond couplings for anions and cations of the CF3 dimer and of CnH2n and CnF2n chains were calculated by ab initio molecular orbital theory. The anions and cations provide systems for which the electron binding energies, Be, differ by about a factor of 10. Through‐space couplings decay exponentially, exp(−βR), with increasing distance, R, between the donor/acceptor carbon atoms. The decay coefficient β varies approximately as B1/2e. In contrast, the decay coefficients for through‐bond coupling in CnF2n and CnH2n chains are not affected significantly by the binding energy of the electron.