Question

Which among the following is Claus formula of benzene?
A.

B.

C.

D.

Answer 1

Claus benzene molecule is a hexagon with six carbon (C) atoms with a hydrogen (H) atom positioned at the corners, with each carbon connected to its two ortho carbons (the nearest carbons) and the one para carbon connected diametrically.

Complete step by step answer:
Claus benzene $\left( {{C_6}{H_6}} \right)$ is a hypothetical hydrocarbon and it is an isomer of benzene. It was proposed by a German chemist, Adolf Karl Ludwig Claus in the year 1867 as a possible structure for benzene at a time when there was still a debate on the structure of benzene. In his model, the six carbon (C) atoms of benzene form a hexagonal shape with a hydrogen atom positioned to every corner. The opposite corners of the hexagon are connected by single bonds to preserve 4 valances for carbon atoms i.e. each carbon is connected to its two ortho carbons and the one para carbon connected diametrically. High strain energy makes Claus benezene’s synthesis impossible. Although it is often referred to alongside Dewar benzene which is option (B) and Prismane, it is not possible to synthesise it, which Dewar benzene and Prismane can be.

Therefore, the correct answer is option (A).

Note: It took many years of research before the three postulated structures of benzene, by Albert Ladenburg in 1869, August Kekulé in 1865 and by Claus in 1867 found their place in organic chemistry. Ladenburg's prismane and Claus' benzene were both proven to be wrong, on the other hand, the prismane was synthesized in 1973. The calculations showed that the synthesis of Claus' benzene is impossible.