Herbert Charles Brown

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Herbert Charles Brown (born May 22, 1912 as Herbert Brovarnik in London , † December 19, 2004 in West Lafayette ) was an American and British chemist .

Life

He was the son of Jewish emigrants from Ukraine . The family moved to the United States in 1914. In the fall of 1935, he began studying chemistry at the University of Chicago and graduated with a BS in 1936. In the same year, he became a US citizen. On February 6, 1937, he married Sarah Baylen. A year later in 1938 he received his Ph. D. from the University of Chicago. After a postdoc period, he became an instructor at the same university for four years. He then moved to Wayne University as an assistant professor. In 1946 he became an associate professor and finally in 1947 a full professor at Purdue University in West Lafayette, Indiana ( USA ). He held this position until his retirement in 1978 and as an emeritus until his death. In 1957 he was elected to the National Academy of Sciences , 1966 to the American Academy of Arts and Sciences . On December 19, 2004, he died of a heart attack in a hospital in Lafayette. He left a son and a granddaughter.

Scientific achievement

In 1979 he received the Nobel Prize for Chemistry together with Georg Wittig . The award was given for merits in the development of boron compounds for important reagents in organic synthesis. Brown discovered most of the reducing agents commonly used today for aldehydes and ketones , such as sodium borohydride and lithium aluminum hydride . He also worked on the addition of boranes to olefins .

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

Brown was embroiled in a decades-long debate with Saul Winstein about the classical or non-classical character of the 2-norbornyl cation (a derivative of norbornane ). He represented the classical interpretation as a carbenium ion , the charge of which changed quickly between two enantiomeric positions in the ring structure, and even wrote a book about it. However, by NMR studies by George A. Olah and colleagues and finally by X-ray structure analysis in 2013, the non-classical character (five-coordinate carbon atom, carbonium ion, the positive charge of which is delocalized between three carbon atoms) was demonstrated.

Web links

Individual evidence

  1. ^ Autobiography on Nobelprize.org .
  2. ^ Brown: The non classical ion problem . Springer, 1977, ISBN 978-1-4613-4120-8 .
  3. ↑ 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, doi : 10.1126 / science.1238849 .
  4. ↑ Mark Peplow: The nonclassical cation: a classic case of conflict . In: Chemistry World, July 20, 2013.
personal data
SURNAME Brown, Herbert Charles
ALTERNATIVE NAMES Brovarnik, Herbert
BRIEF DESCRIPTION American chemist and Nobel Prize winner
DATE OF BIRTH May 22, 1912
PLACE OF BIRTH London
DATE OF DEATH December 19, 2004
Place of death West Lafayette, Indiana