August KekulöL von Stradonitz (Kekule von Stradonitz Friedrich August)( German chemists - organics.)
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Biography August KekulöL von Stradonitz (Kekule von Stradonitz Friedrich August)
(7.IX. 1829 - 13.VII.1896)
German organic chemist. Showed that carbon atoms are tetravalent and can connect with each other in the chain (1858). Sformultroval initial of the theory of valence.
German chemist - organic. Born in Darmstadt. Graduated Gisensky University (1852). I listened to a lecture in Paris F. Dumas, W. Wurtz, W. Zhepapa. In 1856-1858 he. taught at the University of Heidelberg, in 1858-1865 he. - Professor of the University of Ghent (Belgium), from 1865. - University of Bonn (in 1877-1878. - Rector).
His research interests are mainly concentrated in the field of theoretical organic chemistry and organic synthesis.
Received tiouksusnuyu acid and other sulfur compounds (1854), glycolic acid (1856). First, by analogy with the type of water introduced (1854) type of hydrogen sulfide. Suggested (1857) idea of valence as a whole number of units of affinity, which has the atom. Pointing to the "dibasic" (bivalence), sulfur and oxygen. Divide (1857) all elements except carbon, on the one-, two-, and tribasic; carbon is carried to chetyrehosnovnym elements (along with L. V. G. Kolbe).
Launched (1858) position that the constitution of compounds is determined by a "core", ie the valence elements. For the first time (1858) showed that the number of hydrogen atoms associated with n carbon atoms is 2n + 2. Based on the theory of types formulated the original theory of valence. Considering the reaction mechanism of double exchange, suggested a gradual weakening of the original bonds and led (1858) scheme, which is the first model of the activated state. Offered (1865) cyclic structural formula of benzene, thus extending the theory of chemical structure Butlerova of aromatic compounds.
Experimental work KekulöL von Stradonitz closely linked to his theoretical studies. In order to test the hypothesis of the equivalence of all six hydrogen atoms in benzene received his halogen-, nitro-, amino-and karboksiproizvodnye.
Undertook (1864) cycle of transformations acids: natural apple - bromyantarnaya - optically inactive malic. Opened (1866) regrouped in diazoamino-aminoazobenzene. Synthesized trifenilmetan (1872) and anthraquinone (1878). To prove the structure of camphor taken work to transform it into oksitsimol, and then in tiotsimol. Studied the crotonic condensation of acetaldehyde and the reaction of obtaining karboksitartronovoy acid. A new method for thiophene on dietilsulfida and succinic anhydride.
President of the German Chemical Society (1878, 1886, 1891 gg.), One of the organizers of the I International Congress of Chemists in Karlsruhe (1860). Foreign Cor-Cor. St. Petersburg Academy of Sciences (since 1887).
On materials of biographical reference book "Eminent chemists of the world" (by Volkov VA, etc.) - Moscow, "High School", 1991