Snakes, sausages and structural formulae

snake swallowing tail

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Mike Sutton tells the story of how August Kekulé dreamt up the structure of benzene

By the middle of the 19th century, Europe’s chemists knew there was something odd about benzene. Several suspected that its oddness arose from the spatial organization of its atoms, but what their arrangement was remained mysterious. In 1865 the German chemist August Kekulé proposed a cyclic formula which eventually became accepted, although his unwieldy ‘sausage’ symbols were soon discarded.