PASADENA, Calif.—Nelson J. Leonard, one of the most important chemists of the 20th century, died Monday, October 9, at his home in Pasadena, California. He was 90.
Leonard was born on September 1, 1916, in Newark, New Jersey, and attended Lehigh University in Bethlehem, Pennsylvania, before moving to Oxford University as a Rhodes Scholar. The beginning of World War II in September 1939 forced Leonard's return to the United States.
Upon his return, Leonard continued his graduate education in chemistry, concluding with a Ph.D. in 1942 from Columbia University. His research, which focused on structure establishment and partial synthesis of alstonine, a naturally occurring antimalarial compound, was performed under the direction of Robert C. Elderfield.
A postdoctoral research assistantship brought Leonard to the University of Illinois Urbana-Champaign, where he worked with professor Roger Adams on Senecio alkaloids. Teaching duties were added to his research responsibilities in 1943, and his students eventually included U.S. Navy and U.S. Army units passing through the University of Illinois. He joined a team led by professors Charles C. Price III and Harold R. Snyder engaged in research to forward the synthesis and production of the important antimalarial drug chloroquine in time for its use in the Pacific theater.
At the end of the war, during 1945 and 1946, Leonard served as a scientific consultant and special investigator in the Field Intelligence Agency Technical (FIAT), U.S. Army and U.S. Department of Commerce, European Theater. He then returned to the University of Illinois and remained on the teaching staff until his retirement in 1986. Beginning in 1992, he held the position of faculty associate in chemistry at the California Institute of Technology.
From 1943 until 1955, Leonard combined his academic work in chemistry with a flourishing musical career, as he performed as a bass-baritone soloist in choral works with the Chicago, Cleveland, and St. Louis symphony orchestras. When in 1955 Leonard was elected to membership in the National Academy of Sciences, he felt that if his peers had chosen to recognize him as a chemist, then he had "better do something about it." The heavy professional demands of chemistry would take precedence, and there would be no more singing performances.
In collaboration with professor Folke Skoog, a plant physiologist at the University of Wisconsin, Leonard carried out extensive investigations of organic compounds that initiate plant, flower, and tree growth from tissue culture, technology that is central to horticultural and agricultural development. His techniques for derivatization of nucleosides, nucleotides, and coenzymes, and to prepare fluorescent probes, placed him among the most often quoted scientists.
Over the course of his career, he published more than 400 scientific papers and trained more than 200 Ph.D. students and postdoctoral scholars. In addition to his early election to membership in the National Academy of Sciences, Leonard was a fellow of the American Academy of Arts and Sciences and a member of the American Philosophical Society. His research distinctions included the prestigious Roger Adams Award in Organic Chemistry (1981) and Arthur C. Cope Scholar Award (1995) of the American Chemical Society.
Chemistry was not the only part of Leonard's life that was interrupted by the war. Through family connections, he had met and fallen in love with Louise Cornelie Vermey of the Netherlands. They were engaged, but were not able to see each other again until the end of the war in 1945, and were unable to arrange for her journey to the United States and marriage until 1947. She died in 1987.
Leonard is survived by his wife, Peggy Phelps, of Pasadena; his daughter, Marcia, of Maplewood, New Jersey; his sons Kenneth, of Agoura Hills, James, of Olympia, Washington, and David, of Seattle, Washington; and seven grandchildren.
A memorial service is planned for 3 p.m. Monday, November 13, at All Saints Church, 132 North Euclid Avenue, Pasadena. Memorial donations should be made to the Nelson J. Leonard Fund at the Pasadena Symphony.