Rudolph A. Marcus

Rudolph "Rudy" Arthur Marcus (born July 21, 1923) is a Canadian-born chemist who received the 1992 Nobel Prize in Chemistry for his theory of electron transfer. Marcus theory, named after him, provides a thermodynamic and kinetic framework for describing one electron outer-sphere electron transfer. A type of chemical reaction linked to his many studies of electron transfer would be the transfer of an electron between metal ions in different states of oxidation. An example of this type of chemical reaction would be one between a bivalent and a trivalent iron ion in an aqueous solution. In Marcus's time chemists were astonished at the slow rate in which this specific reaction took place. This attracted many chemists in the 1950s and is also what began Marcus's interests in electron transfer. Marcus made many studies based on the principles that were found within this chemical reaction, and through his studies was able to create his famous Marcus theory. This theory gave way to new experimental programs that contributed to all branches within chemistry.

Marcus was born in Montreal, Quebec. His interest in the sciences began at a young age. Rather it was math that first caught his interest for he excelled in it during his years at Baron Byng High School. The next step in his education lay in McGill University where he studied under Doctor Carl A. Winkler. Coincidentally Winkler had studied under another Nobel Prize winner, who was Cyril Hinshelwood at Oxford University. “During my McGill years, I took a number of math courses, more than other students in chemistry.” –Marcus. Marcus’s interest in math would later help him in creating his theory on electron transfer.

Electron transfer is one of the simplest forms of a chemical reaction. It consists of one outer-sphere electron transfer between substances of the same atomic structure likewise to Marcus’s studies between bivalent and trivalent iron ions. Electron transfer may be one of the most basic forms of chemical reaction but without it life cannot exist. Electron transfer is used in all respiratory functions as well as photosynthesis. In the process of oxidizing food molecules, 2 hydrogen ions,2 electrons, and an oxygen molecule react to make an exothermic reaction as well as H₂O (water). Due to fact that electron transfer is such a broad, common, as well as essential reaction within nature, Marcus's theory has become vital within the field of chemistry.

2H+ + 2e- + 1/2 O₂ → H₂O + heat

He earned a B.Sc. in 1943 and a Ph.D. in 1946, both from McGill University. In 1958, Marcus decided to become a naturalized citizen of the United States. He is an active professor at Caltech and Nanyang Technological University, Singapore. He is a member of the International Academy of Quantum Molecular Science.

University of Hyderabad, India conferred the degree of Doctor of Science (honoris causa) to him in 2012.