Kekule, Emil

Shortly after the tetravalent nature of carbon was proposed, extensions to the Kekule-Couper theory were made w7hen the possibility of multiple bonding between atoms was suggested. Emil Erlenmeyer proposed a carbon-carbon triple bond for acetylene, and Alexander Crum Brown proposed a carbon-carbon double bond for ethylene. In 1865, Kekule provided another major advance when he suggested that carbon chains can double back on themselves to form rings of atoms. 

Kekule was not the only important protagonist in the rise of the set of ideas that was ultimately consolidated under the rubric "structure theory" for example, in addition to Williamson, Adolphe Wurtz, Emil Erlenmeyer, Hermann Kolbe, and Edward Frankland also played vital roles. At the time of the birth of the theory all of these men occupied respected positions in their field. Chapter 5 looks at four outsiders— Archibald Couper, Joseph Loschmidt, Aleksandr Butlerov, and Alexander Crum Brown—who at this time were relatively new to the science, but who made their marks in sometimes transformative ways during the years 1858-64. All four had definite ideas on how molecules should be conceived by the scientist and best represented for heuristic purposes. A tour of these figures provides a fuller understanding of the range of responses, opportunities, and creative options that were available during these tumultuous years in the science, and suggests par-... 

Fischer, Emil, 1852-1919 (p. 24, Plate 1), son of a merchant was born in 1852 in Euskirchen (Rhineland) studied chemistry in Bonn (Kekule), StraBburg (A. Baeyer, physics A. Kundt) where he graduated Dr. phil. in 1874. Assistant with Baeyer, from 1874 in Munich. Professor in Erlangen (1882-1885), then in Wurzburg until his call to the famous Chemical Institute of the University of Berlin as successor to A.W.v. Hofmann, in 1892. Amino acid and peptide research from 1900, after extremely successful research in the field of carbohydrates and purines. Fisher died in the summer of 1919 in Berlin. He was the second winner of the Nobel Prize for Chemistry in 1902, after van t Hoff in 1901. 

Emil Fischer (Euskirchen, nr. Bonn, 9 October 1852-Berlin, 15 July 1919), the son of a Protestant merchant, after some hesitation in the choice of a profession studied chemistry under Kekule in Bonn (1871). He graduated under... 

Erlenmeyer," whilst Kekule s, R-N—N-X was adopted by Emil Fischer in his work on phenylhydrazine (1875, P- He thought the formula of phenylhydrazine is more simply related to its preparation from a diazocompound if the formula of this is QH N N X, Blomstrand s formula... 

The start of Emil s higher education had to be delayed because the eighteen-year-old youth had to recover from gastric catarrh before he could leave home. The father sent Emil to the University of Bonn in 1871 to study chemistiy. At Bonn he attended the lectures of Kekule, Engelba, and Zincke. Emil still had a strong interest in physics, and only the peraistent persuasion of his cousin and fellow student, Otto Fischer (1852-1932) prevented him from deserting chemistry. 

One of the great pioneers in the development of carbohydrate chemistry was Emil Fischer, who was born near Bonn, Germany, in 1852. Although he went to the University of Strasbourg to study chemistry under Friedrich Kekule, he actually obtained his Ph.D. under Adolf von Baeyer in 1874. He moved with von Baeyer to Munich, where he received his Habilitation in 1878. He was then appointed as an Ausserordentlicher, or... 

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