Marcus-Hush ideas

It is hardly possible to overestimate the impact that the Marcus-Hush ideas and their experimental exploitation, mainly by Sutin and his coworkers, have made on the study of redox reactions. The treatment here is necessarily brief. Other aspects have been discussed in the references cited. Some important points we have not considered are... 

The concepts outlined in the previous section can be based on a model Hamiltonian [7,13], which combines ideas from the Marcus-Hush [1,2] theory of electron transfer with the Anderson-Newns model [8,9], While the resulting theory explains the principles of electrocatalysis well, it suffers from the well-known defects of the Anderson-Newns-type models it does not account for many-body effects and is therefore not good enough for quantitative calculations. Therefore, we have developed a method to combine our theory with DFT calculations. In the following, we present the main ideas the mathematical details are given in the appendix. 

Marcus[195] gave a quantitative interpretation of this idea and above all, the role of solvent rearrangement within the framework of the absolute rate theory. Later, he also extended these concepts to electrochemical processes[196]. Similar concepts were also developed by Hush[197,198]. An important result of this work was the establishment of the relation between the transfer coefficient for adiabatic reactions and the charge distribution in the transient state. Gerischer[93,199] proposed a very useful and lucid treatment of the process of electron transfer in reactions with metallic as well as semiconductor electrodes. While the works mentioned above were mainly based on transition state theory, a systematic quantum-mechanical analysis of the problem was started by Levich, Dogonadze, and Chizmadzhev[200-202] and continued in a series of investigations by the same group. They extensively used the results and methods of solid state physics, and above all the Landau-Pekar polaron theory[203]. 

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