# Chloranilic acid: a redetermination at 100K

Dutkiewicz, Grzegorz and Yathirajan, H. S. and Al-arique, Q. N. M. Hakim and Narayana, B. and Kubicki, Maciej (2010) Chloranilic acid: a redetermination at 100K. Acta Crystallographica Section E, 66 (2). O497-O498. ISSN 1600-5368

The crystal structure of chloranilic acid, C\sb 6H\sb 2Cl\sb 2O\sb 4, was first described by Andersen in 1967 Andersen, E. K. (1967). Acta Cryst. {\bf 22}, 188{--}191 at room temperature using visually estimated intensities. Taking into account the importance of the title compound, we have redetermined the structure at 100(1)K. The approximately planar mol{\-}ecule the maximum deviation from the mean plane through the ring is 0.0014(9){\AA} for the ring atoms and 0.029(3){\AA} for the other atoms occupies a special position, lying across the center of symmetry. In the crystal structure, a two-dimensional hydrogen-bonded network sustained by O{---}H{$\cdots$}O inter{\-}actions runs approximately parallel to 101. The two-dimensional layers are further packed in a parallel fashion, stabilized by Cl{$\cdots$}Cl inter{\-}actions Cl{$\cdots$}Cl = 3.2838(8){\AA}, C{---}Cl{$\cdots$}Cl = 152.96(6){$^\circ$}.