'Ball and stick’ model of benzene
- Maker: Friedrich August Kekulé (researcher)
- Date: ca. 1865
- Location: Ghent, Belgium
- Collection: History of Sciences
Who was Friedrich August Kekulé?
The German chemist Friedrich August Kekulé (1829-1896) owes his fame to the colourless liquid benzene. He was a professor of organic and inorganic chemistry at Ghent University from 1858 to 1867. During that period, he discovered that the hydrogen and carbon atoms in benzene are arranged in a hexagonal ring structure. This discovery caused nothing short of a revolution in structural organic chemistry.
What is benzene?
Benzene is a colourless liquid that boils at 80 °C. It is a highly flammable, carcinogenic substance, but it does have a pleasant smell. Benzene consists of six carbon and six hydrogen atoms (C6H6). Since its discovery by Faraday in 1825, however, its atomic structure had been a matter of guesswork. Kekulé came up with the hexagonal ring structure in 1865: a hexagon with alternate single and double bonds.
What gave Kekulé the idea for a ring structure?
It is said that during his time in Ghent, Kekulé dozed off in front of an open fire and drew inspiration for the ring structure from a dream in which he saw a snake biting its tail.
Why is this discovery revolutionary?
Kekulé’s insight that hydocarbons did not necessarily have a linear structure formed the basis for an entirely new branch of chemistry: aromatic chemistry. In fact, he is generally considered to be the father of structural organic chemistry. His insights also formed the scientific basis for the extremely rapid growth of the German chemical industry, particularly the dye industry, during the last decades of the 19th century.