Two New Isomers of Benzene Hexachloride

The Stereoisomerism of Cyclohexane Derivatives.

“…), if tetrahedral angles are conserved. The discovery of seven isomers of benzene hexachloride (156,162) demonstrates that the existence of at least one pair of meta polar chlorine substituents does not impart sufficient steric strain to prevent formation of that isomer, although some distortion of the molecule may result. In the case of -benzene hexachloride (pppeee) the steric effect results in a bending out of the lp, 3p carbon-chlorine bonds (315) (figure 8).…”

γ-BHC: Its history and mystery – why is only γ-BHC insecticidal?

“…The structures of β-BHC [16][17][18], γ-BHC [19,20], δ-BHC [21], and ε-BHC [22] were not only elucidated by electron diffraction and X-ray methods, but also by spectrophotometry and dipole moment techniques. Furthermore, these structures were chemically confirmed by the chlorination and/or alkaline dehydrochlorination of BHC isomers [23][24][25][26][27][28][29][30]. For example, Cristol reacted α-, γ-, and δ-BHC isomers with brucine and found that among these isomers, α-BHC is racemic [31].…”

Applications of Molecular Spectroscopy to Relationships Between Biological Activity and Structure.

“…Hexachlorocyclohexane is a mixture of stereoisomers formed by the addition of chlorine to benzene under the influence of actinic light. Seven of the eight expected isomers have been characterized (119); of these the -isomer, which represents about 12 per cent of the product, alone is a highly active insecticide. To obtain further information concerning the relation of structure to insecticidal activity, a critical study was undertaken of the infrared and Raman spectral data as they relate to the molecular configurations of the various isomers (221).…”