1829-1896

German organic chemist who contributed to an understanding of the structure of molecules by the use of the concept of valence. Kekulé believed that each element had a fixed number of other atoms that it could combine with. This led to the development of structural formulas showing the way in which atoms are actually bonded to each other. Kekulé's most important contribution was his explanation of the unusual properties of benzene in 1865, in which he proposed that benzene existed as a ring of six carbon atoms with alternating single and double bonds.