Dr Samuel Isaac Weissman (June 25, 1912 – June 12, 2007) was an American chemist and professor best known for his work on the application of electron spin resonance (ESR) to chemistry.
/ref> Weissman was born in

South Bend, Indiana South Bend is a city in and the county seat of St. Joseph County, Indiana, on the St. Joseph River near its southernmost bend, from which it derives its name. As of the 2020 census, the city had a total of 103,453 residents and is the fourt ...

in 1912. He completed a chemistry degree at the

University of Chicago The University of Chicago (UChicago, Chicago, U of C, or UChi) is a private university, private research university in Chicago, Illinois. Its main campus is located in Chicago's Hyde Park, Chicago, Hyde Park neighborhood. The University of Chic ...

in 1933 and his doctorate from the same university in 1938.Marquis Who's Who, 2006, "Samuel Isaac Weissman" Weissman was working on a project on fluorescent energy transfer, which later led to some rare-earth

laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The firs ...

s, at the

University of California at Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant uni ...

when he was asked to join the

Manhattan Project The Manhattan Project was a research and development undertaking during World War II that produced the first nuclear weapons. It was led by the United States with the support of the United Kingdom and Canada. From 1942 to 1946, the project w ...

developing atomic weapons in 1943. He was among a group who asked unsuccessfully that the bomb not be dropped on civilian targets. After his Los Alamos stint, Weissman went to the

Washington University in St. Louis Washington University in St. Louis (WashU or WUSTL) is a private research university with its main campus in St. Louis County, and Clayton, Missouri. Founded in 1853, the university is named after George Washington. Washington University i ...

in 1946 becoming a full professor in 1955. At Washington University, Weissman worked with others developing the use of

electron spin resonance Electron paramagnetic resonance (EPR) or electron spin resonance (ESR) spectroscopy is a method for studying materials that have unpaired electrons. The basic concepts of EPR are analogous to those of nuclear magnetic resonance (NMR), but the s ...

. He was one of the first, probably in parallel with

Clyde Hutchison Clyde A. Hutchison III is an American biochemist and microbiologist notable for his research on site-directed mutagenesis and synthetic biology. He is Professor Emeritus of Microbiology and Immunology at the University of North Carolina at Chape ...

, to measure the hyperfine splitting of the ESR line caused by the interaction with nuclear spins. This hyperfine splitting is the main source of the sensitivity of ESR to the chemical environment of the electron, and hence it underlies the broad applications of ESR in chemistry. Much of his work concerned the way this interaction term behaves as molecules tumble around in solution or undergo chemical reactions. He also investigated the special non-equilibrium ESR effects which are found as reactions take place. Weissman was a member of the

United States National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nat ...

. Weissman retired from Washington University in 1980 and died in June 2007. He was married to a distinguished psychologist,

Jane Loevinger Jane Loevinger Weissman (February 6, 1918 – January 4, 2008) was an American developmental psychologist who developed a theory of personality which emphasized the gradual internalization of social rules and the maturing conscience for the orig ...

References

1912 births 2007 deaths 20th-century American chemists Members of the United States National Academy of Sciences Washington University in St. Louis faculty Jewish American scientists Manhattan Project people Rare earth scientists {{US-scientist-stub