Question

Which conformation of \[{{{C}}_{{6}}}{{{H}}_{{6}}}{{C}}{{{l}}_{{6}}}\] is the most powerful insecticide?
A.aaeeee
B.aaaeee
C.aaaaee
D.aaaaaa

Answer 1

Hint:In the question, ‘a’ refers to an axial position. Axial positions or axial bonds are perpendicular to the plane of the ring. While ‘e’ stands for an equatorial position. Equatorial positions or equatorial bonds are around the plane of the ring. So these are two types of positions of bonds on a plane.

Complete step by step answer:
Out of the given four confirmations of \[{{{C}}_{{6}}}{{{H}}_{{6}}}{{C}}{{{l}}_{{6}}}\] whose IUPAC name is 1,2,3,4,5,6-hexachloro cyclobenzene.
The common name of \[{{{C}}_{{6}}}{{{H}}_{{6}}}{{C}}{{{l}}_{{6}}}\] is benzene hexachloride (BHC). It was first prepared in 1825. But its insecticidal properties were discovered later in 1944.
-aaaeee conformer or gamma-conformer of Benzene hexachloride is 1000 times more toxic than any other conformation of benzene hexachloride.
-When chlorine is made to react with benzene several stereoisomers of benzene hexachloride are formed. Gamma-isomer makes up about 20 to 25 percent of this mixture of products.
-The above conformer which acts as an insecticide is known as lindane or gammexane.
-The confirmation in which the compound is the most powerful insecticide is aaaeee. The structure of the confirmation is:

-Since gamma-isomer is more soluble as compared to other conformers in certain solvents, it is separated by dissolved mixtures of products in some solvents.
-Lindane is more volatile than DDT and thus has a faster but less protracted action on insects.
-The confirmation in which the compound is the most powerful insecticide is aaaeee.
Hence, the correct option is B.


Note:
Some discoveries prove that lindane gets accumulated in the food chain, this phenomenon is known as bio-accumulation. This phenomenon is coupled with biomagnification. This means as we move higher in the food chain, the concentration of lindane increases. Acute exposure to linden can cause nerve dysfunction.