This project is in the general area of analytical and surface chemistry and in the subfield of electrochemistry. During the tenure of this three-year continuing grant, Professor Creager and his students will study electron transfer over long distances in organized monolayers. This research will focus specifically on the role that the local medium, particularly the bridging structure between reactants, plays in dictating the rate and pathway for electron transfer. Using novel ferrocene-capped rigid polyphenylene oligomers attached to gold microelectrodes via thiol termini, the temperature dependence of electron transfer rates on ion pairing and other local medium effects will be investigated. The structure of these rigid monolayers will be characterized by surface x-ray scattering experiments that will be carried out at Brookhaven National Laboratory. %%% This research is expected to enhance the current understanding of long range electron transfer processes that are of central importance to many biological functions such as photosynthesis and cellular energy transduction involving redox proteins.