Isomerism of benzoquinone monoximes: XV The crystal structure of 2,6-di-tert-butyl-4-(p-bromophenyl)imino-2, 5-cyclohexadien-1-one†

Crystals of the title compound are monoclinic. The space group is P21//n, the lattice constants are a = 11.07, b = 11.38, c = 15.61 A, β = 98.9° and Z = 4. The structure was solved by the conventional heavy-atom technique based upon photographic X-ray data. Intramolecular bond distances and valency angles are listed and appear to be quite regular. The dihedral angle between the phenyl and the cyclohexadiene ring amounts to 56°. The latter ring is slightly distorted towards the boat form. The tert-butyl groups exhibiting a pronounced thermal libration about their bonds to the cyclohexadiene ring, are not disordered.