Rudolph A. Marcus and His Theory of Electron Transfer Reactions
Rudolph A. Marcus was awarded the 1992 Nobel Prize in Chemistry "for his contributions to the theory of electron transfer reactions in chemical systems". 'According to Chemistry Chairman Norman Sutin, some of the early definitive tests of Marcus's theoretical work were done … at [Brookhaven National Laboratory (BNL)] … .
Marcus's Nobel Prize-winning work is a mathematical analysis of how the overall energy in a system of interacting molecules changes and induces an electron to jump from one molecule to another. It sheds light on many complex chemical reactions, including photosynthesis, corrosion and electrical conductivity in polymers. …
Marcus ... was on the faculty of Polytechnic Institute of Brooklyn from 1951 to 1964. He started working on his electron-transfer theory in the early 1950s and soon discovered … a strong experimental program at Brookhaven on electron-transfer reactions. …
Beginning in 1958, Marcus had a series of formal appointments at BNL, ranging from consultant to visiting senior chemist to research collaborator. …
[Sutin said] "Theory is not cut- and-dried; it's an evolving thing. We had a lot to do with getting Marcus's theory accepted because our experimental work provided the first verification of several of the predictions of his theory. This, in turn, gave him confidence that it was worth pursuing." …
Early BNL studies of electron- transfer reactions used radioactive isotopes to examine the simplest class of reactions, the electron-exchange reaction, In which there is no net chemical change. Such reactions are most conveniently studied by using a radioactive isotope to label the chemical form containing the electron. The chemical forms with and without the electron are then separated as a function of time and their radioactivity determined. This provides a measure of the electron transfer rate. …
"Marcus was intrigued by the early exchange results," said Sutin, "and they, in turn, reinforced his interest in electron-transfer theory. He soon extended his early electron-transfer work to include reactions accompanied by a net chemical change, in theoretical work that came to be called the Marcus cross-relation."
In the late 1980s, a group at Argonne National Laboratory … provided the best confirmation of a remaining prediction of the Marcus theory, namely, experimental evidence for the so-called "inverted region" where rates decrease with increasing driving force.'
Additional information about Rudolph Marcus and the Marcus theory is available in electronic documents and on the Web.
Generalization of the Activated Complex Theory of Reaction Rates. I. Quantum Mechanical Treatment, DOE Technical Report, 1964
Generalization of the Activated Complex Theory of Reaction Rates. II. Classical Mechanical Treatment, DOE Technical Report, 1964Application of Electron-Transfer Theory to Several Systems of Biological Interest, DOE Technical Report, 1985
Additional Web Pages:
Interview with Rudolph Marcus, nobelprize.org (video)
Interview with Rudolph A. Marcus, Oral History Project, California Institute of Technology Archives, Pasadena, California
Perspective on the "M" in RRKM Theory: an Interview with the Nobel Laureate Rudolph A. Marcus, The Spectrum, Volume 16, Issue 2, Summer 2003, Page 4
Rudolph A. Marcus, (video)