August Wilhelm von Hofmann - Biography

Chemist, born in Giessen, WC Germany. He became first director of the Royal College of Chemistry in London (1845), and was chemist to the Royal Mint (1856–65). He went to Berlin as professor of chemistry in 1865, founded the German Chemical Society (1868), and was ennobled in 1888. He obtained aniline from coal products, discovered many other organic compounds, including formaldehyde (1867), and devoted much labour to the theory of chemical types. His work was of importance to the aniline-dye industry.

August Wilhelm von Hofmann (April 8, 1818 – May 5, 1892) was a German chemist.

Biography

Hofmann was born at Gießen (Hesse). The general culture he thus gained stood him in good stead when he turned to chemistry, the study of which he began under Justus von Liebig. When, in 1845, a school of practical chemistry was started in London, under the style of the Royal College of Chemistry, Hofmann, largely through the influence of the Prince Consort, was appointed its first director. In 1864 he returned to Bonn, and in the succeeding year he was selected to succeed Eilhard Mitscherlich as professor of chemistry and director of the laboratory in Berlin University.

Hofmann's work covered a wide range of organic chemistry. His first research, carried out in Liebig's laboratory at Giessen, was on coal-tar and his investigation of the organic bases in coal-gas naphtha established the nature of aniline.

The Hofmann rearrangement and Hofmann elimination reaction bear his namesake. Hofmann was also the first to introduce molecular models into his public lectures around 1860, following the earlier (1855) suggestion by his colleague William Odling that carbon is tetravalent. This legacy is still remembered nowadays by continuing use of Hofmann's colour scheme: (nitrogen = blue, oxygen = red, chlorine = green, sulfur = yellow, hydrogen = white, as cited by W. Ollis, "Models and molecules", Proceedings of the Royal Institution of Great Britain, (1972), 45, 1-31). The models look rather odd nowadays, primarily because Hofmann had them built so that the carbon was planar, and smaller in size than the hydrogen! It was not until 1874, when Jacobus Henricus van't Hoff and (independently) Joseph Achille Le Bel suggested carbon can be tetrahedral, that molecular models assumed their modern appearance.

William Perkin was a student of his at the Royal College of Chemistry in London, when he discovered the first aniline dye, mauveine.