Researched
Chemical Structure Theory (Kekulé)
In 1857-58 Kekulé shows that carbon forms four bonds and links into chains; in 1865 he proposes benzene as a ring. Molecules become structures that can be drawn, counted and predicted.
Open in the interactive tree →Kekulé announced carbon's four-fold valence in 1857 and the linking of carbon atoms into chains in May 1858; Couper and Butlerov reached the same idea at the same time. His six-membered ring of 1865 explained why benzene has only one monosubstituted and three disubstituted forms. Organic chemistry grew explosively afterwards, and three of the first five chemistry Nobel Prizes went to his students van 't Hoff (1901), Fischer (1902) and Baeyer (1905).
Prerequisites
- Atomic Theory (Dalton)1808Atoms combine in fixed numbers, so each has a fixed valence
- Organic Synthesis (Wöhler)1828Organic compounds are built from the same atoms as inorganic ones
Unlocks
- Plastics (Bakelite to Nylon)1907-1953Polymers and nylon are designed as chains of atoms joined by known bond patterns.
- Quantum Chemistry & Bonding1927Lewis, Heitler-London and Pauling explain the valences and bonds that structure theory drew as lines