Alfred Stock

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Alfred Stock
Emil Fischer
Doctoral studentsH. J. Emeléus

Alfred Stock (July 16, 1876 – August 12, 1946) was a German

coordination chemistry, mercury, and mercury poisoning
. The German Chemical Society's Alfred-Stock Memorial Prize is named after him.

Life

Stock was born in Danzig (

Emil Fischer he got his doctoral degree.[2]

In 1899 he worked with the French chemist and toxicologist Henri Moissan in Paris for one year. He was given the task of synthesizing still unknown compounds of boron and silicon. Five years later he became professor at the

Technische Hochschule in Karlsruhe from 1926 to 1936. In 1932 he was a visiting professor at Cornell University in Ithaca, New York for four months.[2]

A member of the NSDAP (National Socialist German Workers' Party) since 1933, Stock was anti-Semitic.

Second World War damaged the house of Stock. In September 1943 he and his wife moved to Bad Warmbrunn in Silesia, but the flow of refugees forced them to move again towards west in February 1945. They found accommodation in Aken (near Dessau). After the war in 1946, Stock endeavoured to revitalize German chemistry by lectures and memoirs.[2] He was renowned for his pioneering research on boron hydrides.[4]

Research on the hydrides of boron and silicon

In 1909 Stock began studying the boron

Breslau. Due to their extreme reactivity and flammability in air, boron hydrides could not be purified until his development of methods for separation using high-vacuum manifolds around 1912. He performed similar work on the hydrides of silicon. The hydrides of boron and silicon represented the first family of binary compounds to approach the richness of hydrocarbons in terms of structural diversity. Not only did the boron hydrides exhibit challenging properties, their structures were also unusual. Elucidation of the structures and the associated bonding models dramatically expanded the scope of inorganic chemistry. Boron hydrides such as diborane later developed into a range of reagents for organic synthesis as well as a source of diverse ligands and building blocks for researchers. With Henri Moissan, Stock discovered silicon boride
.

Research in other areas of inorganic chemistry

In 1921, Stock first prepared metallic beryllium by electrolyzing a fused mixture of sodium and beryllium fluorides. This method made beryllium available for industrial use, such as in special alloys and glasses and for making windows in X-ray tubes.

He was also influential in

coordination chemistry. The term "ligand" (from ligare Latin, to bind) was first used by Stock in 1916.[5] H. Irving and R.J.P. Williams adopted the term in a paper published in 1948.[6] Monodentate, bidentate, tridentate characterized the number of ligands attached to a metal. Given the introduction of ligand concept, he was also able to further derive the idea of bite angle and other aspects of chelation
.

The "Stock system," first published in 1919, was a system of nomenclature on

binary compounds. In his own words, he considered the system to be "simple, clear, immediately intelligible, capable of the most general application." In 1924, a German commission recommended Stock system to be adopted with some accommodations. FeCl2, which would have been named iron(2)-chloride according to Stock's original idea, became iron(II) chloride in the revised proposal. In 1934 Stock agreed to the use of Roman numerals
but preferred keeping the hyphen and dropping the parentheses. Although this suggestion has not been followed, the Stock system remains in use worldwide.

Interests in mercury and mercury poisoning

Stock published over 50 papers on different aspects of

micromercurialism was first used.[8]

Retirement and death

After retirement in 1936, Stock moved from Karlsruhe to Berlin. He died in Aken, a small town near Dessau, in August 1946 at the age of 70.

Posthumous recognition

In recognition of his contributions to the field of inorganic chemistry, the German Chemical Society (Gesellschaft Deutscher Chemiker) created in 1950 the Alfred Stock Memorial Prize. The prize, consisting of a gold medal and money, is awarded every other year for "an outstanding independent scientific experimental investigation in the field of inorganic chemistry."[9]

Publications

  • Praktikum der quantitativen anorganischen Analyse. Berlin 1909, (6. Auflage, München 1979).
  • Ultrastrukturchemie. Berlin 1920.
  • Hydrides of boron and silicon. Ithaca(USA) 1933, (Neuausgabe Ithaca(UAS) 1957).
  • Die Gefährlichkeit des Quecksilbers und der Amalgam-Zahnfüllungen. Berlin 1928.
  • Das Atom In: Angewandte Chemie Band 37, Nr. 6, 1924,
    doi:10.1002/ange.19240370602
    , S. 65–67.

Inventions and discoveries

  • the tension thermometer[2]
  • the Stock high vacuum apparatus - an apparatus made of glass which allows work with highly combustible and poisonous substances to be undertaken in high vacuum.[2]
  • the principles of the chemistry of metal-chelate complexes
  • Stock nomenclature or the Stock system - the system of naming the oxidation state of an atom in a compound[10]

References

  1. ^ A. Piloty, A. Stock: Über eine quantitative Trennung des Arsens vom Antimon. Band 30, 1649, 1897
  2. ^
    doi:10.1002/cber.19500830619
    .
  3. ISSN 1868-0054
    , S. 633–637.
  4. ^ Stock, Alfred (1933). The Hydrides of Boron and Silicon. New York: Cornell University Press.
  5. doi:10.1016/S0277-5387(00)88023-7
    .
  6. S2CID 6943144
    .
  7. ^ Sella, Andrea (2014-05-20). "Stock's valve".
  8. doi:10.1002/ange.19260391502.. Translated by Birgit Calhoun Archived 2012-10-21 at the Wayback Machine
    .
  9. ^ "Gesellschaft Deutscher Chemiker e.V., GDCh-Preise 2008". de:Gesellschaft Deutscher Chemiker. 2007. Archived from the original on 2008-03-05.
  10. ^ Alfred Stock: Zur Nomenklatur und Registrierung anorganischer Stoffe. In: Chem.-Ztg. Band 33, 205, 1909.

External links

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