Hans Freiherr[a] von Pechmann (1 April 1850 – 19 April 1902) was a German chemist, renowned for his discovery of diazomethane in 1894.[1][2] Pechmann condensation[3][4] and Pechmann pyrazole synthesis.[5] He also first prepared 1,2-diketones (e.g., diacetyl), acetonedicarboxylic acid, methylglyoxal and diphenyltriketone; established the symmetrical structure of anthraquinone.

Hans von Pechmann
Born1 April 1850
Died19 April 1902(1902-04-19) (aged 52)
NationalityGerman
Alma materUniversity of Greifswald
Known forPechmann condensation Diazomethane
Scientific career
Fieldsorganic chemistry
InstitutionsUniversity of Munich University of Tübingen
Doctoral advisorHeinrich Limpricht
Doctoral studentsWilliam Hobson Mills Julius B. Cohen

Von Pechmann also produced the first example of solid polyethylene serendipitously in 1898, via the decomposition of diazomethane.

Life edit

Von Pechmann was born in Nürnberg, the only son of a doctor, who was also named Hans. The von Pechmanns had distinguished themselves as soldiers; in 1702, von Pechmann's ancestor Martin Günther von Pechmann, a general of artillery in the Bavarian army, had been raised to the rank of a baron of the Holy Roman Empire by Leopold I.[6] After studying with Heinrich Limpricht at the University of Greifswald he became professor at the University of Munich till 1895. He was professor at the University of Tübingen from 1895 until his death. He killed himself by taking cyanide, aged 52.[6]

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  1. ^ Regarding personal names: Freiherr is a former title (translated as Baron). In Germany since 1919, it forms part of family names. The feminine forms are Freifrau and Freiin.

References edit

  1. ^ H. von Pechmann (1894). "Ueber Diazomethan". Berichte der deutschen chemischen Gesellschaft. 27 (2): 1888–1891. doi:10.1002/cber.189402702141.
  2. ^ H. von Pechmann (1895). "Ueber Diazomethan". Berichte der deutschen chemischen Gesellschaft. 28 (1): 855–861. doi:10.1002/cber.189502801189.
  3. ^ H. von Pechmann, Carl Duisberg (1883). "Ueber die Verbindungen der Phenole mit Acetessigäther". Berichte der deutschen chemischen Gesellschaft. 16 (1): 2119–2128. doi:10.1002/cber.188301602117.
  4. ^ H. von Pechmann (1884). "Neue Bildungsweise der Cumarine. Synthese des Daphnetins". Berichte der deutschen chemischen Gesellschaft. 17 (1): 929–936. doi:10.1002/cber.188401701248.
  5. ^ H. von Pechmann (1898). "Pyrazol aus Acetylen und Diazomethan". Berichte der deutschen chemischen Gesellschaft. 31 (3): 2950–2951. doi:10.1002/cber.18980310363.
  6. ^ a b Koenigs, Wilhelm (1903). "Hans von Pechmann". Berichte der Deutschen Chemischen Gesellschaft. 36 (4): 4417–4511. doi:10.1002/cber.190303604134.