Marcus Theory proposes that the reaction rate of an electron transfer decreases when ΔG is too large. It was proposed by Rudolph Marcus in the 1950s and experimentally verified in the 1980s. Marcus would receive the Nobel Prize in Chemistry in 1992 for this theory. Electron transfer (ET) is the process by which an electron moves from one atom or molecule to another atom or molecule. ... In thermodynamics, free energy is a measure of the amount of mechanical work that can be extracted from a system. ... Rudolph Arthur Marcus (born July 21, 1923) received the 1992 Nobel Prize in Chemistry for discovering the theory of electron transfer reactions in chemical systems. ...

The free energy change of a reaction, ΔG, is the driving force behind a reaction and determines the extent to which it proceeds. Usually, the more negative ΔG is, the faster the reaction proceeds. In dealing with electron transfers, this is true up until a certain point (called the Normal region), however after this point a more negative ΔG yields a slower reaction rate (called the Inverted region), which is quite counterintuitive. The graph of reaction rate vs. free energy change therefore produces a parabola, with the maximum rate of ET occuring when ΔG=λ, where λ is defined as the reorganization energy of the reaction. In thermodynamics, free energy is a measure of the amount of mechanical work that can be extracted from a system. ...

Marcus Theory is used in various aspects of chemistry and biology, including photosynthesis, corrosion, certain types of chemiluminescence and more. Leaf. ... Corrosion, atmospheric and biologic (Barnacles) Corrosion is deterioration of useful properties in a material due to reactions with its environment. ... Chemoluminescence (sometimes chemiluminescence) is the emission of light (luminescence) as the result of a chemical reaction. ...

Additional Information

Biography of Marcus and explanation of his contribution

Marcus' Nobel Lecture