KOH Walter

KOH, WALTER (Kohn, Walter) (p. 1923) (USA). Nobel Prize in Chemistry, 1998 (jointly with D. Pople).

Born in Vienna on March 9, 1923 to a wealthy Jewish family. His father, Solomon Kohn - publisher of books on art, mother, Gittel, received an excellent education and sought to give his children. Con 5 years went to an academic high school, where he was attracted by the Greek and Latin. It all ended when the Anschluss took place in 1938. The boy briefly studied at school, intended for the Jews, where, incidentally, physics professor, former assistant of Einstein. Parents Kohn, and teachers were killed during the Holocaust. Unlike other members of the family nurse in 1938 could leave the country and Cohn joined her in England. He could not get a higher education during the war, because, like other people from a hostile country, was interned in Canada. The war ended, but stay in Canada for formal reasons, delayed. Kohn and three of his peers took a Canadian family, and then he served a year in the army. All this time he studied mathematics at the University of Toronto and graduated with honors in 1946.

He was granted a scholarship for graduate school at Harvard University (USA), where he defended his thesis in 1948 and stayed for a couple of years as an instructor. In 1950 he was accepted to work at Carnegie Mellon University.

In 1960, Cohn moved to the University of California at San Diego, where he headed the physics department from 1961 to 1963. Here he created the theory, which was subsequently awarded the Nobel Prize.

The method of molecular orbitals developed by RS Mulliken (Nobel Laureate, 1966), an understanding of the qualitative aspect of the formation of chemical bonds and electronic structure of molecules.

The invention of the computer scientists has provided a powerful tool, and Mulliken himself and his colleagues first created a computer program to decipher the structure of molecules.

In 1964-1965 Kohn showed that the energy of the quantum-mechanical system is uniquely determined by its electron density. This quantity is easier to calculate than the complex wave function in the Schrodinger equation. Cohn has also developed a method (the theory of functions of density), which provided an opportunity to select the equation in such a way that their solutions gave values of electron densities and energies of the system. This method, like the method of English physicist D. Pople, widely used by chemists because of its simplicity.

Quantum mechanical calculations give the energy for each molecular structure, which may occur during a chemical reaction. Energy curve for this reaction route, . thus obtained, . taking into account the molecular structures of transition states (maxima on the graph) and intermediates (at least on the curve) provides an answer to the fundamental possibility of this transformation,
.

Methods of quantum-mechanical calculations of Pople and Kohn, nowadays routinely used for computer interpretation of data in all fields of chemistry. With the help of computer calculation methods to create new catalysts, drugs and polymeric materials. The correct choice of the active center of enzymes with the number of atoms of 20 to 60 allows to settle the mechanisms of its binding to metabolites (antimetabolites) and the subsequent biochemical transformation of the substrate, . is necessary for the needs of Biochemistry, . Toxicology, . pharmacology and clinical medicine,
. The structure surrounding the active site of the enzyme protein part is described simply. For example, was designed mechanism to protect muscle myoglobin of carbon oxide poisoning. It turned out that this can be achieved only through the formation of hydrogen bond with one oxygen molecule from the amino acids of the protein molecule myoglobin, which can not occur with a molecule of CO.

In 1979, Cohn became the director of the Institute of Theoretical Physics, University of California at Santa Barbara, which released in 1984, to remain there as a professor. In 1991 he retired, but continues to work actively as a Distinguished Professor.

In 1998, Cohn and J. Pople was awarded the Nobel Prize 'for the development of the theory of functions of density'.

Cohn at different times on probation in Pennsilvanskom, Michigan, Washington, Paris, Jerusalem University, Imperial College in London and the Federal Institute of Technology in Zurich. For 50 years he has been consultant to the Atomic Energy Commission United States (1960-1972), . laboratories firms 'Vestingaus' (1953-1957), . 'Bell Telephone' (1953-1966) and IBM (1978), collaborated with national laboratories in Brukheyvene, . Argonne, . Oak Ridge, . with the Ames Laboratory, . with the department of physics at Tel Aviv University, . from Brown University and Simon Fraser, . Harvard, . Michigan and Tulane University, . with reactor department of the National Institute of Getisberge, . with the Academic Senate of South Dakota, a member of the Board Veytsmannovskogo Institute of Science and others,
.

Cohn at various times lived or visited in Austria, Britain, Canada, USA, France, Switzerland, Denmark, Israel. A lot of time given to protecting the world and is part of a series of public pacifist organizations. Hobbies - listening to classical music, weekly skating and sometimes cook something in the kitchen.