Archibald Scott Couper
and
August Kekule von Stradonitz

In 1857, Kekule proposed that carbon was tetravalent.

In 1858, Kekule and Couper, two very imaginative thinkers (remember they did not have the analytical tools like IR and NMR that we have available today!!), simultaneously and independently recognized that carbon atoms can link to each other to form chains. Prior to this thinking, it was believed that molecules could only have one central atom. This idea made it much easier to explain the multitude of organic compounds that were being discovered.

Couper was a Scot who was educated in Glasgow, Edinburgh, Berlin and Paris. Couper began with the study of classical languages and philosophy. It is believed that this background probably enabled him to make the connection between the letters in words and the atoms in molecules. He is credited with inventing the use of straight lines to indicate bonds which of course is still used today. Though he made his discovery at the same time as Kekule, he was technically scooped. Couper had given his important paper to Charles Adolphe Wurtz (another famous organic chemistry) for presentation at the French Academy. Wurtz procrastinated (he needed to attend a BMC procrastination workshop) in delivering the paper to the Academy and it was not presented until three weeks after that of Kekule. After this, Couper had sort of a emotional collapse and retreated to his home in Scotland. He never published another scientific paper.

Kekule was a German of Czech decent. His family had wanted him to study architecture, but he grew interested in chemistry after attending lectures by the famous chemist Liebig at the University of Giessen. While working as a research assistant in London, he was riding home on a bus after visiting a chemist friend. While daydreaming, he "saw" carbon atoms join together in a "giddy dance". This was the beginning of his idea for carbons linking together in chains.

Kekule is credited with writing the first organic chemistry textbook called "Lehrbuch der organischen chemie". Some people feel this book was the birth of organic chemistry as a separate and distinct subject. The following is a quote from Kekule about a dream he had while working on this book....

"I was sitting writing at my text book, but the work did not progress; my thoughts were elsewhere. I turned my chiar to the fire, and dozed. Again the atoms were gamboling before my eyes. This time the smaller groups kept modestly in the background. My mental eye, rendered more acute by repeated visions of this kind, could now distinguish larger structures of manifold conformations; long rows, sometimes more closely fitted together; all twisting and turning in snake-like motion. But look! What was that? One of the snakes had seized hold of its own tail, and the form whirled mockingly before my eyes. As if by a flash of lightning I woke;... I spent the rest of the night working out the consequences of the hypothesis. Let us learn to dream, gentlemen, and then perhaps we shall learn the truth."

The above gave Kekule the idea for the benzene ring structure......something we will soon be studying!!!!

[ B a c k t o H i s t o r y o f C h e m i s t r y ]