Friedrich August Kekulé von Stradonitz

-: Friedrich August Kekulé von Stradonitz :-

Friedrich August Kekulé von Stradonitz

Friedrich August Kekule von Stradonitz (also August Kekulé; German pronunciation: [ˈfriːdrɪç ˈaʊɡʊst ˈkekuːle fɔn ʃtraˈdoːnɪts]) (7 September 1829–13 July 1896) was a German organic chemist. From the 1850s until his death, Kekule was one of the most prominent chemists in Europe, especially in theoretical chemistry. He was the principal founder of the theory of chemical structure.

Kekulé never used his first given name; he was known throughout his life as August Kekulé. After he was ennobled by the Kaiser in 1895, he adopted the name August Kekule von Stradonitz, without the French acute accent over the second "e". The French accent had apparently been added to the name by Kekulé's father during the Napoleonic occupation of Hesse by France, in order to ensure that French speakers pronounced the third syllable.

Kekulé was born in Darmstadt, the son of a civil servant. After graduating from secondary school, in 1847 he entered the University of Giessen, with the intention of studying architecture. After hearing the lectures of Justus von Liebig he decided to study chemistry. Following his education in Giessen, he took postdoctoral fellowships in Paris (1851–52), in Chur, Switzerland (1852–53), and in London (1853–55), where he was decisively influenced by Alexander Williamson.

In 1895 Kekulé was ennobled by Kaiser Wilhelm II of Germany, giving him the right to add "von Stradonitz" to his name, referring to a possession of his patrilineal ancestors in Stradonice, Bohemia. Of the first five Nobel Prizes in Chemistry, his students won three: van 't Hoff in 1901, Fischer in 1902 and Baeyer in 1905.

A larger-than-life size monument of Kekulé is situated in front of the former Chemical Institute at the University of Bonn. His monument is often decorated in by students, e.g. for Valentine's Day.

In 1856 Kekulé became Privatdozent at the University of Heidelberg. In 1858 he was hired as full professor at the University of Ghent, then in 1867 he was called to Bonn, where he remained for the rest of his career. Basing his ideas on those of predecessors such as Williamson, Edward Frankland, William Odling, Auguste Laurent, Charles Adolphe Wurtz and others, Kekulé was the principal formulator of the theory of chemical structure (1857–58).

This theory proceeds from the idea of atomic valence, especially the tetravalence of carbon (which Kekulé announced late in 1857) and the ability of carbon atoms to link to each other (announced in a paper published in May 1858), to the determination of the bonding order of all of the atoms in a molecule. Archibald Scott Couper independently arrived at the idea of self-linking of carbon atoms (his paper appeared in June 1858), and provided the first molecular formulas where lines symbolize bonds connecting the atoms.

For organic chemists, the theory of structure provided dramatic new clarity of understanding, and a reliable guide to both analytic and especially synthetic work. As a consequence, the field of organic chemistry developed explosively from this point. Among those who were most active in pursuing early structural investigations were, in addition to Kekulé and Couper, Frankland, Wurtz, Alexander Crum Brown, Emil Erlenmeyer, and Aleksandr Mikhailovich Butlerov.