Activated Sterically Strained C=N Bond in N-Substituted p-Quinone Mono- and Diimines: XVII. Cyclohexene Polyhalogen Structures Originating from N-(Arylsulfonyl)-p-quinone Imines

Abstract

Sterical hindrances in N-(arylsulfonyl)-1,4-benzo(naphtho)quinone mono- and -diimines and in half-quinoid structures originating therefrom and having bulky equatorially located substituents in both α-positions are manifested in two competing ways: either by a deviation of the fragment C=N–S from the plane of the ring (therewith the torsion angle C=C–C=N may attain 36 deg, the distance of the sulfur atom from the plane 1.69 Å), or by the increased bond angle C=N–S to 132–133 deg. In all investigated cases the activated sterically strained bond C=N appeared at the value of the angle C=N–S >130 deg.