Saul Winstein

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Saul Winstein (born October 8, 1912 in Montreal , † November 23, 1969 in Los Angeles ) was a Canadian-American chemist who dealt with physical organic chemistry .

Winstein came to the USA in 1923, went to Jefferson High School in Los Angeles, studied at the University of California, Los Angeles (UCLA) with a bachelor's degree in 1934 and a master's degree in 1935 (while still a student he published with his professor William Gould Young ) and received his PhD from Caltech with Howard Lucas in 1938 (silver and mercury complexes of olefins). As a post-doctoral student he was with Paul D. Bartlett at Harvard University and then an instructor at the Illinois Institute of Technology and from 1941 at UCLA. In 1947 he was given a full professorship at UCLA, where he remained until his death.

He investigated the influence of neighboring groups on cation formation in organic chemistry and coined terms such as homoconjugation, homoaromaticity , non-classical ions and anchimeric support.

Non-classical (A) and classical (B) view of the 2-norbornyl cation

In 1949 he proposed the non-classical ion character of the 2-norbornyl cation, resulting in a decades-long dispute with Herbert C. Brown led. Winstein believed that the carbocation in norbornyl (a norbornane derivative) would be five-fold coordinated and that the positive charge would be distributed over three carbon atoms (two-electron, three-center bond). A related approach sees this as an intramolecular alkene- carbenium complex. Following Winstein's suggestion, there were soon numerous structural interpretations of non-classical ions in the literature. Brown, on the other hand, criticized this and interpreted the structure classically as a carbenium cation (i.e. three-coordinate carbon atom) that quickly switched between two enantiomeric positions. George A. Olah and co-workers convinced most chemists of the non-classical concept through NMR studies up until the 1980s. The non-classical interpretation in this decades-long dispute was finally proven in 2013 (the molecule was successfully examined by X-ray crystallography).

He received the ACS Award in Pure Chemistry in 1948 , the James Flack Norris Award in 1967 and the Franklin Memorial Award in Chemistry in 1968. In 1970 he received the National Medal of Science . Winstein was a member of the National Academy of Sciences (1955) and the American Academy of Arts and Sciences (1966). Since 1964 he was a corresponding member of the Bavarian Academy of Sciences .

A professorship for organic chemistry at UCLA is named after him.

He had been married since 1937 and had a son and a daughter. In 1929 he became a US citizen.

Web links

Individual evidence

  1. ↑ biographical data, publications and Academic pedigree of Saul Winstein at academictree.org, accessed on January 1, 2018th
  2. ↑ F. Scholz, D. Himmel, FW Heinemann, P. v. R. Schleyer, K. Meyer, I. Krossing: Crystal Structure Determination of the Nonclassical 2-Norbornyl Cation, Science, Volume 341, 2013, pp. 62-64, abstract
  3. ↑ Sylvia Feil, Non-Classical Carbocation Proven, Chemistry in Our Time, Volume 47, 2013, p. 341
  4. ^ Mark Peplow, Chemistry World, July 20, 2013
  5. ^ Saul Winstein obituary by Rolf Huisgen in the 1970 yearbook of the Bavarian Academy of Sciences (PDF file).
personal data
SURNAME Winstein, Saul
BRIEF DESCRIPTION Canadian-American chemist
DATE OF BIRTH October 8, 1912
PLACE OF BIRTH Montreal
DATE OF DEATH November 23, 1969
Place of death los Angeles