Science & People

August Kekule | Biography, education, discoveries, quotes, and facts

Friedrich August Kekule was the chief creator of the chemical structure theory, a method to follow the detailed architecture of complex molecules. One of the most obvious applications of this theory was related to chemicals known as "aromatic". This new understanding accelerated the chemical industry that flourished at the end of the 19th century.

I turned my chair towards the fireplace and sank into half-sleep. Again the atoms fluttered before my eyes … But look, what was that? One of the snakes had seized its own tail, and the figure whirled mockingly before my eyes. I awoke in a flash, and this time, too, I spent the rest of the night working out the consequences of the hypothesis.

From August Kekule's speech in 1890

Who is August Kekule?

Kekule was born in Darmstadt, the capital of Hesse, a small, independent country in central Germany. His father was a member of the cabinet of the Grand Duke, and since he wanted his son to be an architect, August began to study architecture in a small university in the country in the north of Giessen. At that time, one of the best-known chemists was among the faculty members; After attending Justus von Liebig's lessons, August became passionate about chemistry.

As the Kekule approached the end of his education, Liebig advised him to take postdoctoral training, partly because there was not an available position for chemists. Finally, Kekule made three training trips, one to Paris, one to Switzerland, Chur, and the last to London. He was later admitted to Heidelberg University as a faculty member. After two and a half years in this position, in the fall of 1858, he was appointed chemistry professor at Ghent University in the French-speaking region of Belgium.

Nine years later, when he was then one of the most famous chemists in Europe, he called to the University of Bonn and completed the rest of his professional life in this city in the Rhine region. Although Kekule was happy to return to his country, he was unhappy in his private life. His young and beautiful wife died while giving birth to his first children, and he could not find happiness in his second marriage.

Forward-thinking theorist

The formula expressing the two equivalent forms of the ring-like structure of the Kekule's benzene molecule.
The formula expressing the two equivalent forms of the ring-like structure of the Kekule's benzene molecule.

In the 1840s, chemists began developing possible ways to detect the sequence of atoms in molecules, but there were also many opposing ideas and confusions in this regard. The young theoretical chemist Kekule found himself at the forefront of these discussions. He had the advantage of having an intense professional practice not only in Germany, but also in France, England, Switzerland, and Belgium. A number of European scientists were just beginning to develop a theory about the valence of atoms—for example, a hydrogen atom combines with another atom only with one bond, where oxygen atoms with two, and nitrogen atoms with three, or carbon atoms with four (even to four different atoms).

According to the story that Kekule told in his old age, during his third post-doctoral educational trip, a molecule image appeared before his eyes while dreaming on the upper floor of the London bus, which was pulled by horses on a summer evening in 1855. When he got home, he wrote in detail how many molecules could be separated into atoms one by one. The important thing here was not each carbon atom connected to only four other atoms, but the linear carbon atom bonds they formed once linked. He published this theory three years later; The main doctrine of a chemical theory soon became an invaluable guide to chemical analysis and synthesis.

In the same speech, Kekule talked about the second dream he saw in the evening of 1862 while half-asleep in front of the fireplace in his own apartment in Ghent. He saw a snake seized its own tail. This molecular dance, which this time appeared in front of his eyes and not in his mind, gave him the clue that the benzene molecule—the main structure of chemicals called "aromatic"—could be in the shape of a ring, not a straight line. This idea formed the essence of his benzene theory, published in 1865.

August Kekule and organic chemistry

Coincidentally, the synthetic dye industry was turning into a huge market at that time, especially in Germany, and almost all new paints were benzene derivatives. In fact, not only dyes, but drugs, food chemicals, ammunition, plastics, and all kinds of synthetic materials were built on aromatic structure. Kekule's newer and better scientific understanding of these substances played a key role in the production research and was the main factor in the sudden growth of many new chemical industries.

Kekule was one of the most creative scientists of the 19th century. His extraordinary energy and sense of humor, bright personality, and scientific charisma attracted international students, friends, and fans. But it was his own citizens who were most grateful to him, as Kekule approached the end of his life, Germany had become an international leader in organic chemistry, led by his ideas. These ideas form the basis of organic chemistry today.

August Kekule quotes

  • "Let us learn to dream, gentlemen; then we shall perhaps find the truth."
  • "We define organic chemistry as the chemistry of carbon compounds."
  • "Originally a pupil of Liebig, I became a pupil of Dumas, Gerhardt and Williamson: I no longer belonged to any school."