August Kekule

August Kekulé was a German organic chemist who established the foundation for the structural theory in organic chemistry. He was one of the most prominent chemists in Europe from the 1850s until his death, especially in theoretical chemistry. He was the principal founder of the theory of chemical structure and in particular the Kekulé structure of benzene. Kekulé was born in Darmstadt, the capital of the Grand Duchy of Hesse, on September 7, 1829. He was the son of a civil servant and showed an aptitude for art and languages, as well as science subjects. He initially intended to study architecture at the University of Giessen, but after hearing the lectures of Justus von Liebig, he decided to study chemistry instead. He obtained his doctoral degree in 1852 under Liebig's supervision. After his graduation, Kekulé worked as an assistant in various places, such as Paris, Chur and London. In London, he was influenced by Alexander Williamson, who introduced him to the idea of linking atoms by valence bonds. Kekulé developed this idea further and proposed that carbon atoms can form chains by linking to each other with four valence bonds. He also suggested that carbon atoms can have different arrangements in space, leading to the concept of isomerism. In 1856, Kekulé became a lecturer at the University of Heidelberg and in 1858, he was appointed as a professor at the University of Ghent. There he continued his research on organic chemistry and published his famous paper on the structure of benzene in 1865. He proposed that benzene has a cyclic structure with alternating single and double bonds between six carbon atoms. He claimed that he had a dream of a snake biting its own tail, which inspired him to come up with this idea. In 1867, Kekulé moved to Bonn, where he remained until his retirement in 1896. He founded a chemical journal called Chemische Berichte and organized several international congresses of chemistry. He also wrote a textbook on organic chemistry, which was widely used by students and researchers. He received many honors and awards for his contributions to chemistry, such as the Copley Medal from the Royal Society and the Pour le Mérite from the Kaiser. Kekulé married Stephanie Drory in 1858 and they had six children. His wife died in 1894 and he himself died of pneumonia on July 13, 1896 in Bonn. He was buried at the Alter Friedhof cemetery in Bonn.