Charge on the move: how electron-transfer dynamics depend on molecular conformation

This tutorial review illustrates the many facets whereby the molecular conformation helps to control the rates of through-bond electron transfer. A brief introduction to Marcus theory is given, highlighting the importance of the coupling element and the super-exchange mechanism, before considering the reasons why the coupling element might depend on the molecular geometry. The methods currently available for determination of both the coupling element and the geometry are reviewed and various examples are given for systems where the structure controls the degree of electronic coupling along the molecular axis. The role of the bridge connecting the donor and acceptor is emphasized.