 |
Kekule,
von Stradonitz, Friederich August German chemist Born: Darmstadt, Hesse, September 7, 1829 Died: Bonn, Prussia, July 13, 1896 | |||||||||
Arrhenius Berzelius Bunsen Cannizzaro Curie Dalton Kekule Lavoisier Lecoq De Boisbaudran Mendeleev |
Kekule had intended to be an architect, but found himself drawn more towards chemistry. He lectured at Heidelberg University and set up a private laboratory for his own work. In 1856 he obtained a professorship at Heidelberg. Kekule was interested in the valence theory proposed by Cannizarro and Frankland. While chemical symbols were in common use for compounds such as sodium chloride, NaCl, water H2O, ammonia NH3, according to the method advanced by Berzelius, Kekule got the idea that fixed combinations of atoms could be arranged in patterns, for example, water became H-O-H. Atoms could also be linked by double and triple bonds in a variety of ways. Kekule turned his attention to the element carbon, and was able to explain that it was tetravalent, i.e. one carbon atom can combine with four others. This also introduced the concept of molecule chains, where carbon molecules interlock in a successive structure. This discovery also explained the existence of isomers, different compounds with the same chemical composition, just arranged differently, e.g. ethyl alcohol and dimethyl ether. The advent of the structural formula created an opportunity for chemists to begin experimenting with the synthesis of new compounds. In 1861 Kekule published what is considered to be the first textbook of organic chemistry. In 1865, Kekule made a further breakthrough. While sitting on a bus, he began to see atoms whirling in a dance. Suddenly the tail end of one atom attached itself to the head and formed a spinning ring. Kekule thus introduced the concept of rings of carbon atoms, solving a problem in connection with the atomic structure of benzene (C6H6). In 1867 Kekule moved to the University of Bonn, where he spent the remainder of his life. Atomic structure was later developed further into three-dimensional models which became the basis for the quantum mechanics of Planck. | |||||||||
| ||||||||||
vb-tech.co.za