Alexander Butlerov

Aleksandr Butlerov developed and named the theory of chemical structure in 1861, proposing that the properties of a substance depend on the arrangement of atoms within its molecules and that atoms bond according to specific valences. This theory established that molecular architecture—not just composition—determines chemical behavior.

Butlerov presented his theory of chemical structure at a scientific congress in Speyer, Germany, in 1861. His formulation was developed around the same time that August Kekulé and Archibald Couper were independently proposing similar structural ideas.

The reaction that Butlerov reported in 1861 involves the formation of sugar-like compounds from formaldehyde under basic conditions, later known as the formose reaction. This was one of the earliest demonstrations that complex organic molecules could be synthesized from very simple precursors.

Butlerov was born in 1828 in the region of Kazan in the Russian Empire and was a professor at Kazan University, where he established a significant school of Russian organic chemistry. He later moved to St. Petersburg University, continuing his influential work in both theoretical and synthetic chemistry.