Rudolph A. Marcus

He married Laura Hearne in 1949 and had three children. His wife died in 2003 after being together for more than five decades.

Rudolph Arthur Marcus was born on July 21, 1923, in Montreal, Quebec, to Esther (née Cohen) and Myer Marcus. The only son of the couple, he was raised in a loving environment and grew up admiring his father’s athletic abilities and his mother’s musical talents.

Two of his uncles were highly educated and the young boy idolized them. He loved going to school and became interested in both science and mathematics. After completing his schooling from Byng High School, he joined McGill University—the alma mater of the uncles he admired so much.

Studying under Dr. Carl A. Winkler at the university was an enriching experience for Marcus. Even though he was primarily a chemistry student, he also took several courses in mathematics which he later credited to have aided him in creating his theory on electron transfer. He earned a B.Sc. in 1943 and a Ph.D. in 1946 with a thesis titled ‘Studies on the conversion of PHX to AcAn.’

After receiving his doctorate, Rudolph A. Marcus joined the new post-doctoral program at the National Research Council (NRC) of Canada in Ottawa. The photochemistry group was headed by E.W.R. Steacie who was a major force behind the development of the basic research program at NRC.

In the late 1940s Marcus began applying to theoreticians in the US for a postdoctoral research fellowship and received a favorable response from Oscar K. Rice at the University of North Carolina. He joined the university in 1949 and was exposed to theoretical research which paved the way for his career as a theorist.

In the early 1950s he developed the RRKM theory ("Rice-Ramsperger-Kassel-Marcus") by blending statistical ideas from the RRK theory of the 1920s with those of the transition state theory of the mid-1930s. The work was first published in 1951, and the next year he wrote the generalization of it for other reactions.

In 1951, he joined the Polytechnic Institute of Brooklyn, beginning his life as a fully independent researcher. There he undertook an experimental research program on both gas phase and solution reaction rates, and wrote two papers on electrostatics in 1954-55.

In 1964, he joined the faculty of the University of Illinois in Urbana-Champaign where he became interested in varied aspects of reaction dynamics, including designing "natural collision coordinates." He went to Europe as a Visiting Professor at the University of Oxford in 1975 and later went to the Technical University of Munich as a Humboldt Awardee. It was at Munich that he was first exposed to the problem of electron transfer in photosynthesis.

Rudolph A. Marcus developed what became known as the Marcus theory, a theory that explains the rates of electron transfer reactions – the rate at which an electron can move or jump from one chemical species (called the electron donor) to another (called the electron acceptor). Originally formulated to address outer sphere electron transfer reactions, it was later extended to include inner sphere electron transfer contributions as well.

Marcus took the Rice–Ramsperger–Kassel theory developed by Rice and Ramsperger in 1927 and Kassel in 1928 and integrated it with the transition state theory developed by Eyring in 1935 to introduce the Rice–Ramsperger–Kassel–Marcus (RRKM) theory. The theory enables the computation of simple estimates of the unimolecular reaction rates from a few characteristics of the potential energy surface.