Paul Havrez

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Paul Havrez (born July 19, 1838 in Herstal near Liège , † 1875 ) was a Belgian chemist.

Havrez attended the Athenaeum in Liège and studied at the École des Mines, des Arts et Manufactures in Liège with a diploma as a mining engineer in 1861. In the same year he became professor of physics and chemistry at the École des Mines et des Arts Industriels in Lille . In 1862 he moved to the École Professionelle de Verviers as a chemistry professor and director. He died of tuberculosis when he was only 37 . He dealt primarily with textile chemistry and the textile trade, but also retained an interest in basic chemical research and visited August Kekulé in Ghent around 1864 , but also other chemists such as Robert Wilhelm Bunsen in Heidelberg.

In a paper published shortly after Kekulé's announcement of the cyclical nature of benzene in 1865, he proposed symmetrical three-dimensional models of benzene (one with two triangles lying one above the other, the other cylinder shape) based on the "sausage models" for molecules that were common at the time. Since he published it in a technical journal, it received little attention then or later, with the exception of Kekulé himself, who mentions these models in his book Textbook of Organic Chemistry from 1866. In his work, Havrez refers to discussions with Kekulé, who also used "sausage models" in his publication, albeit linear ones with arrows to indicate cyclicality. Havrez also published other three-dimensional models of inorganic and organic molecules in his paper.

literature

  • E. Heilbronner, J. Jacques: Paul Havrez and his benzene formula . In: Chemistry in Our Time. 1998, 32, pp. 256-264.

Remarks

  1. ↑ hydrogen was spherical; Oxygen, nitrogen and carbon were cylinders, each with a length corresponding to the valency, i.e. two, three and four times the diameter of the sphere. According to John Dalton, the bond was imagined in such a way that particles of the same type repel each other and attract different types.
  2. ↑ Paul Havrez: Principes de la Chimie unitaire . Rev. Univers. Mines metal. Mec., 1865, vol. 18, 318, 433.
  3. ↑ Ferdinand Enke, Erlangen, pp. 514/515
personal data
SURNAME Havrez, Paul
BRIEF DESCRIPTION Belgian chemist
DATE OF BIRTH July 19, 1838
PLACE OF BIRTH Herstal near Liège
DATE OF DEATH 1875