Johannes Thiele (chemist)

Source: Wikipedia, the free encyclopedia.
Friedrich Karl Johannes Thiele
University of Munich,
University of Straßburg
Doctoral advisorJacob Volhard
Doctoral studentsHeinrich Otto Wieland,
Jakob Meisenheimer,
Hermann Staudinger,
Otto Dimroth,
Sir Robert H. Pickard[1]

Friedrich Karl Johannes Thiele (May 13, 1865 – April 17, 1918) was a German chemist and a prominent professor at several universities, including those in Munich and Strasbourg. He developed many laboratory techniques related to isolation of organic compounds. In 1907 he described a device for the accurate determination of melting points,[2] since named Thiele tube after him.[3]

Thiele was born in Ratibor,

University of Munich from 1893 to 1902, when he was appointed professor of chemistry at Strasbourg.[5]

He developed the preparation of glyoxal bis(guanylhydrazone).[6]

After

Kekulé's proposal for benzene structure in 1865, Thiele suggested a "Partial Valence Hypothesis", which concerned double and triple carbon-carbon bonds with which he explains their particular reactivity. In 1899 this led to the prediction of the resonance that existed in benzene, and he proposed a resonance structure, by using a broken circle to represent the partial bonds.[7] Later this problem was completely solved with the advent of quantum theory
.

In 1899, Thiele was head of

Organic Chemistry at the Bavarian Academy of Sciences in Munich. With his associate Otto Holzinger, he synthesised an iminodibenzyl nucleus: two benzene rings attached together by a nitrogen atom and an ethylene bridge.[8]

He discovered the condensation of ketones and aldehydes with cyclopentadiene as a route to fulvenes. He also recognized that these deeply colored species were related to but isomeric with benzene derivatives.[9]

According to one of his students Heinrich Otto Wieland, Thiele had a dislike of the chemistry of natural products.[10]

References

  1. ISBN 978-0-8122-8207-8
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  2. ISSN 1099-0682
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  3. doi:10.1002/ange.19180314901
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  4. doi:10.1002/cber.19270600633
    .
  5. ^ Thiele, Friedrich Karl Johannes (1999). A Dictionary of Scientists. Vol. 1. Oxford: Oxford University Press.
    ISBN 9780192800862
    .
  6. PMID 13523604
    .
  7. ^ Thiele, Johannes (1899) "Zur Kenntnis der ungesättigten Verbindungen" (On our knowledge of unsaturated compounds), Justus Liebig’s Annalen der Chemie,306: 87-142; see: "VIII. Die aromatischen Verbindungen. Das Benzol." (VIII. The aromatic compounds. Benzene.), pages 125-129.
  8. ISBN 978-0-19-517668-1
    .
  9. doi:10.1002/cber.190003301113
    .
  10. ISBN 978-0-19-861443-2
    .
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