Ladenburg, Albert

Ladenburg, Albert. Vortrdge tiber die Entwicklungsgeschichte der Chemie von Lavoisier zur Gegenwart. Braunschweig Vieweg, 1869. 

The puzzling behavior of benzene, its unreactivity, and the inference that all six carbon atoms must be linked in the same way could not be described by an open carbon chain (or vertebrate), nor was it satisfactory to write one true "rational" formula for "empirical" C6H6 benzene. Albert Ladenburg s nonplanar prism formula was the best single representation,... 

For a time the prism formula VI, proposed in 1869 by Albert Ladenburg of Germany, was considered as a possible structure for benzene, on the grounds that it would yield one monosubstitution product and three isomeric disubstitution products. 

Albert Ladenburg, born Jul. 2, 1842, in Mannheim, Germany, died Aug. 15, 1911, in Breslau, now Poland. 

The story was told years later, in letters to Anschutz, by Adolf Lieben, who was there at the time, and by Albert Ladenburg, who had the story directly from Wurtz (Anschutz, "Couper," 200-201). Lieben also mentioned that Couper had privately shown him the manuscript of the paper for comment, even before he had given it to Wurtz for publication. Lieben could therefore verify Couper s independence from Kekul at first hand. 

Jungbunziauer Ladenburg GmbH, Dr. Albert-Reimann-Strasse 18, 68526 Ladenburg, Germany (Tel 49 6203 104 0 FAX 49 6203 104 210 E-mail Jungbunzlauer Jungbunzlauer.de)... 

Ladenburg benzene An (erroneous) structure for benzene proposed by Albert Ladenburg (1842-1911), in which the six carbon atoms were arranged at the comers of a triangular prism and linked by single bonds to each other and to the six hydrogen atoms. 

For more complicated atoms Bohr, by ingenious methods, arrived at a scheme for the structure of atoms which corresponds with the periodic table. He assigned incomplete inner groups of electrons to the atoms of the so-called transitional elements , which explained the anomalous behaviour of the rare-earth elements. This had been foreshadowed in a periodic table proposed by Julius Thomsen, in which the transitional elements occur in the middle of long rows, and was suggested by Rudolf Ladenburg (son of the chemist Albert Ladenburg), professor of physics in Breslau. Successive electrons added to the atomic structure of such elements fill shells below the valency electrons, and hence the chemical properties remain fairly constant as the atomic numbers increase. 

Although these criticisms might seem to us to be very serious, to the chemists of the day the hexagonal structure for benzene solved so many problems that it was widely accepted. The reason for the equivalence of the carbon-carbon bonds and for the lack of reactivity remained matters for speculation, but the fundamental concept of the hexagonal ring encountered little opposition. The only serious alternative was the prism formula of Albert Ladenburg (1842-1911), but, while this... 

Albert Ladenburg (1842-1911) was a student of Kekule vide infra) who showed, by chemical reactions, the equivalence of the hydrogens of benzene. Ladenburg eventually became Professor at University of Breslau. 

Ladenburg benzene An incorrect structure for BENZENE in which the six carbon atoms are at the corners of a triangular prism. It is named for Albert Ladenburg (1842-1911). The actual compound, known as prismane, was synthesized in 1973. 

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