Auwers, Karl Friedrich von

(b. Gotha, Germany, 16 September 1863; d. Marburg, Germany, 3 May 1939)

chemistry.

Auwers was a master organic chemist who investigated problems in structural theory for more than fifty years. He was a student of A. W. von Hofmann at Berlin, an assistant to Victor Meyer at GŌttingen and Heidelberg, and then director of the chemical institute at the University of Marburg. On joining Victor Meyer, he became involved in stereochemical studies. In 1888 Auwers and Meyer substituted the name “stereochemistry” for van’t Hoff’s “chemistry in space.” At this time the concept of geometrical isomerism had not been extended to structures other than those involving carbon atoms. Auwers and Meyer found that there were three isomeric forms of benzildioxime

and proposed, contrary to van’t Hoff’s principle of the free rotation of single bonds, that the isomerism resulted from the restricted rotation about the singly bound carbon atoms. Arthur Hantzsch and Alfred Werner elaborated the presently accepted theory in 1890 by extending geometric isomerism from doublebonded carbon atoms to double-bonded carbon and nitrogen atoms. Auwers and Meyer themselves aided in the confirmation of the Hantzsch and Werner theory.

Auwers’ studies on isomerism led him into a lifelong investigation of stereochemical problems. He mastered the difficult art of assigning configuration to stereoisomers, establishing the configuration of the crotonic acids as well as many other geometric isomers. Auwers also investigated the spectrochemistry of organic compounds, the relation of physical properties to molecular structure, and molecular rearrangements, the most outstanding result of these studies being the determination of the keto-enol proportions in many tautomeric mixtures.

BIBLIOGRAPHY

Auwers was a prolific organic chemist, publishing over 500 papers in German journals from 1884 to 1938. A bibliography of his periodical publications, with a biographical notice by Hans J. Meerwein, is in Berichte der Deutschen chemischen Gesellschaft, 72 (1939), 111–121. His only book is Die Entwicklung der Stereochemie (Heidelberg, 1890). Among his important early papers with Victor Meyer on the stereochemistry of oxime compounds are “Untersuchungen ūber die zweite van’t Hoffsche Hypothese,” in Berichte....21 (1888), 784–817; “Weitere Untersuchungen über die Isomerie der Benzildioxime,” ibid., 3510–3529; and “Über die isomeren Oxime unsymmetrischer Ketone und die Konfiguration des Hydroxylamins,” ibid., 23 (1890), 2403–2409. His unraveling of the spatial configuration of the crotonic acids is found in “Über die Konfiguration der Crotonsāuren,” in Berichte..., 56 (1923), 715–791, written with H. Wissebach. Among the many important papers on the relation between physical properties and chemical constitution are “Zur Spektrochemie und Konstitutionsbestimmung tautomerer Verbindungen,” in Annalen der Chemie, no. 415 (1918), 169–232; “Über Beziehungen zwischen Konstitution und physikalischen Eigenschaften hydroaromatischer Stoffe,” ibid., no. 420 (1920), 84–111; and “Zur Bestimmung der Konfiguration raumisomerer Äthylenderivate,” in Zeitschrift fūr physikalische Chemie, 143 (1929), 1–20, written with L. Harres.

Albert B. Costa