Three polychloromononitrobenzenes: C6H3Cl2NO2, C6H2Cl3NO2 and C6HCl4NO2

3,5-Dichloronitrobenzene (I), 3,4,5-trichloronitrobenzene (II) and 2,3,5,6-tetrachloronitrobenzene (III) are frequently used as intermediates in the manufacture of dyes as well as phyto-sanitary and drug products. In both compounds (I) and (II), the NO 2 plane and the benzene ring plane are coplanar, but in (III) these planes have a mean dihedral angle of 88°