Acta Cryst. (2005). E61, o1061-o1063  [ doi:10.1107/S1600536805007634 ]

2,9-Dichloro-5,12-dihydroquino[2,3-b]acridine-7,14-dione

T. Senju, T. Hoki and J. Mizuguchi

Abstract: The title compound, C₂₀H₁₀Cl₂N₂O₂, is an industrially important red pigment. The molecule has inversion symmetry. The molecule is not entirely planar, as shown by the dihedral angle of 176.7  (3)° between the planes of the benzene ring at the center and that at the extremity. The molecules are stacked in a `hunter's fence' fashion (i.e. when viewed from the side, the molecules cross one another with an angle of about 50° in a grid-like structure) along the a axis.

Online 25 March 2005

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