The history of the discovery of benzene_Kain Industrial Additives

Benzene was first synthesized in the early 19th century when coal gas was studied as a lighting gas.

G. T. Accum produced many products from 1803 to 1819, some of which were found to contain a small amount of benzene using modern analytical methods.

In 1825, Michael Faraday (Michael Faraday) isolated higher-purity benzene from the thermal cracking products of fish oil and other similar substances, which he called It is "Bicarburet of hydrogen" (Bicarburet of hydrogen). And some physical properties of benzene and its chemical composition were measured, and it was stated that the carbon-hydrogen ratio of benzene molecules is C:H=1:1, and the experimental formula (the simplest formula) is CH.

In 1833, Milscherlich determined the experimental formula (C6H6) of 6 carbons and 6 hydrogen atoms in the benzene molecule.

In 1845, German chemist Hoffmann discovered benzene from the light fraction of coal tar, and his student C. Mansfield subsequently processed and purified it. Later he invented the crystallization method to refine benzene. He also conducted research on industrial applications and pioneered ways to process and utilize benzene.

In 1861, chemist Johann Jasef Loschmidt first proposed the alternating single and double bond structure of benzene, but his results were not taken seriously.

In 1865, Friedrich Kekulé reconfirmed the structure of benzene four years earlier in his paper "Research on Aromatic Compounds". For this reason, benzene's This structure is named "Kekulé type". He explained this structure by saying that the position of the double bond in the ring is not fixed and can move quickly, so 6 carbons are equivalent. Through research on the monochlorinated and dichlorinated species of benzene, he discovered that benzene has a ring structure, with each carbon connected to a hydrogen.

In addition, James Dewar discovered an analogue of benzene; named "Dewar's benzene", it has been confirmed that it can be obtained from benzene by illuminating light.

In 1865, benzene became an industrial product. Originally recovered from coal tar. As its use expanded, its output continued to rise, and by 1930 it had become one of the top ten products in the world.