Friedrich August Kekulé was an important chemist born on September 7, 1829 in Germany. He developed formulas for organic compounds, created some postulates for the carbon atom, and formulated the structure of benzene.
He began his academic studies at the University of Giessen, studying architecture. Influenced by Justus von Liebig, he moved to the Chemistry course. He completed his doctorate in 1852 and went to study in Paris, France.
He became a university professor in Germany at the University of Heidelberg in 1856. In Belgium, at the University of Ghent in 1858, he was responsible for a chemistry chair.
In the same year, he proved that the carbon atom is tetravalent and that together they form carbonic chains. This idea paved the way for understanding open chain compounds. It was announced almost simultaneously, but independently, by Archibald Scott Couper.
In 1857, he described Kekulé's Postulates on the carbon atom. In 1865, he had a dream that made him formulate the structure of benzene. Said Kekulé:
“I was sitting at the table writing my compendium, but the work would not yield; my thoughts were elsewhere. I turned the chair over to the fireplace and started to sleep. Again the atoms began to somersault in front of my eyes. This time the smaller groups kept modestly at a distance. My mental vision, sharpened by repeated visions of this kind, could now distinguish larger structures with varying conformations; long lines, sometimes aligned and very close together; all twisting and turning in twisting motions. But look! What is that? One of the snakes had threaded its own tail and the shape it twirled mockingly before my eyes. As if lightning had taken place, I woke up; I spent the rest of the night checking the consequences of the hypothesis. Let us learn to dream, gentlemen, for then perhaps we will realize the truth. "
After this dream, he found the possibility of a benzene molecule having this snake-like behavior. He then concluded the cyclic and hexagonal formula of benzene.
He has also done work on organic, unsaturated and sulfur acids and mercury fulminate. He left a valuable work on Organic Chemistry divided into 4 volumes and several articles in scientific journals.
He died in Bonn on July 13, 1896.