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Kharasch, Morris Selig

Kharasch, Morris Selig

(b. Kremenets, Ukraine, Russia [formerly Krzemieniec, Poland], 24 August 1895; d. Chicago, lllinois, 7 October 1957)

organic chemistry.

Although his parents, Selig and Louise Kneller Kharasch and his brothers immigrated to the United States when he was thirteen years old. An older brother in Chicago helped care for the children upon their arrival. Kharasch received his B.S. degree from the University of Chicago in 1917 and his Ph. D. from th same institution two years later, despite his service in 1918 with the Gas Flame Division of the Army. There he worked on toxic gases at Johns Hopkins and the Edgewood Arsenal. He was later (1926) a consultant with the Chemical Warfare Service.

After graduation Kharasch became a research fellow in organic chemistry at Chicago. From 1922 until 1924 he was at the University of Maryland, first as an associate professor and then as a full professor. He returned to the University of Chicago as associate professor of chemistry in 1928 and remained with that institution until his death; in 1935 he was promoted to professor. just prior to his death in 1957 he became director of the Institute of Organic Chemistry, which had been created in his honor by the university. He was one of the founders of the Journal of Organic Chemistry and late in life became American editor of Tetrahedron, an international journal of organic chemistry. He married Ethel May Nelson in 1923 and had two children.

Kharasch is best known for his studies, begun in 1930, on the addition of hydrogen bromide to unsaturated organic compounds. He and his student Frank Mayo carefully determined that in the absence of peroxides, “normal” Markovnikov addition occurs—that is, the hydrogen adds to that largest number of hydrogen atoms. When peroxides are present, however (even in small amounts such as in the use of old reagents), reverse addition occurs. An understanding of the free radical mechanism of this peroxide effect soon followed, and Kharasch applied these ideas to other chemical systems.

During World War II Kharasch collaborated with Frank Westheimer, his colleague at the University of Chicago, in the investigation, greatly aiding the U.S. government’s synthetic rubber program. For his efforts he received the Presidential Merit Award in 1947. For his synthetic of alkyl mercury compounds (developed in 1929) he received the John Scott Award in 1949. His varied chemical interests are shown by his patents for a treatment of fungus disease in small grains and his isolation of the active principle (ergotocine) in ergot. He also assisted in preparation of the thermochmical section of the International Critical Tables.


I. Original Works. The first of Kharasch’s on the peroxide effect is M. S. Kharasch’s and Frank R. Mayo, “Peroxide Effect in the Addition of Reagents to Unsaturated Compounds . I The Addition of Hydrogen Bromide to Allyl Bromide,” in Journal of the American Chemical Society, 55 (1933), 2468-2468. Many of his other important research results appear in the patent literature.

II. Secondary Literature. Details of Kharasch’s personal life can be found in early edition of American Men of Science. His scientific contributions are discussed in detail in Cheves Walling, “The Contributions of Morris S. Kharasch to Polymer Chemistry,” in Tetrahedron, supp. 1 (19590, pp. 143-150; this article also cites his pertinent papers. An elementary discussion of his discovery of the papers, An elementary discussion of his discovery of the peroxide effect is R. D. Billinger and K. Thomaas Finaley, “Morris Selig Khaarasch, a Great American Chemist, “Chemistry, 38 (June 1965), 19-20.

Sheldon J. Kopperl

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