Marcus, Rudolph Arthur (1923-…), a Canadian-born theoretical chemist, now a U.S. citizen, studied the ways in which electrons (negatively charged particles that make up the outer layers of atoms) are transferred between one atom and another in chemical reactions. The progress he made in this topic earned him the 1992 Nobel Prize for chemistry.
Marcus was born in Montreal. He was fascinated by science and mathematics from an early age. He took his first degree and Ph.D. at McGill University, Montreal. Marcus then did postdoctoral experimental work at the National Research Council of Canada in Ottawa. His experiments concerned photochemistry, the chemistry of reactions in which light plays a part, such as the chemistry of photographic film or of photosynthesis in plants.
In 1948, Marcus moved to the United States and switched to theoretical chemistry at the University of North Carolina. After completing postdoctoral work there, he joined the Polytechnic Institute of New York (now the New York University Tandon School of Engineering) in New York City. A problem raised by a student in one of his classes in the mid-1950’s prompted him to study electrolytes, materials that break down when in liquid solution to form ions (atoms and molecules that have too few or too many electrons and are therefore electrically charged). He now did the work that was to bring him the Nobel Prize, clarifying the processes of transfer of electrons between atoms in chemical processes. He related the speed of progress of reactions to the changes in structure of the molecules taking part. Marcus was doing some experimental work at this time, feeling the need to supplement the scanty data available. But by 1960, he gradually stopped experimenting and concentrated instead on theory.
In 1964, Marcus continued his work at the University of Illinois at Urbana-Champaign, and even extended his reading to the motion of astronomical bodies in the search for ideas that would help him. In 1978, he became professor of chemistry at the California Institute of Technology. Marcus became a naturalized U.S. citizen in 1958.
