organic papers o4618 Hussain et al. C 16 H 11 FO 4 doi:10.1107/S1600536806038189 Acta Cryst. (2006). E62, o4618–o4620 Acta Crystallographica Section E Structure Reports Online ISSN 1600-5368 (E)-3-(1,3-Benzodioxol-4-yl)-2-(4-fluoro- phenyl)acrylic acid Mukhtiar Hussain, a Saqib Ali, a * Tahira Zahur, a Muhammad Hanif a and Helen Stoeckli-Evans b a Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan, and b Institute of Microtechnology, University of Neucha ˆtel, Rue Emile-Argand 11, CH-2009 Neucha ˆtel, Switzer- land Correspondence e-mail: drsa54@yahoo.com Key indicators Single-crystal X-ray study T = 173 K Mean (C–C) = 0.004 A ˚ R factor = 0.044 wR factor = 0.122 Data-to-parameter ratio = 11.4 For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e. Received 16 September 2006 Accepted 18 September 2006 # 2006 International Union of Crystallography All rights reserved In the solid-state structure of the title compound, C 16 H 11 NO 4 , the double bond is E, and the mean planes through the two aromatic rings are inclined to one another by 64.81 (12) . In the crystal structure, symmetry-related molecules are linked by O—HO hydrogen bonds, forming centrosymmetric carboxylic acid dimers. The crystal structure is further stabilized by C—HO and C—HF intermolecular hydrogen bonds, leading to the formation of a slab-like structure, two molecules thick, extending in the ab plane. Comment Cinnamic acid derivatives are used in the Shikimic acid metabolic pathways of higher plants (Forgo ´ et al. , 2005). These compounds are also widely used as starting materials for the synthesis of antimalarial drugs. The presence of a fluoro group has been shown to increase their effectiveness in prototype medicinals (Nodiff et al. , 1971). The title compound, (I), a fluorinated phenylacrylic acid, was synthesized for such studies. The molecular structure of compound (I) is shown in Fig. 1, and selected bond distances and angles are given in Table 1. The bond lengths and angles are similar to those found in (E)- 3-(6-nitro-1,3-benzodioxol-5-yl)-2-phenylacrylic acid, (II) (Hussain et al., 2006), and 3-(4-nitrophenyl)-2-phenylacrylic acid, (III) (Kuleshova et al., 2003). The F1—C13 bond distance is quite normal (Allen et al., 1987). The central C C bond (C8 C9) shows clear double-bond character, and bonds C1— C8 and C9—C10 single-bond character, which confirms the localized bonding. The C1–C6 benzene ring is not perfectly planar and has a weighted average absolute torsion angle of 2.6 (Domenicano et al. , 1975) compared to 1.1 in (II). This is explained by the lower precision of the crystal structure analysis of compound (I) (see Experimental refinement section). The planar C10–C15 benzene ring is inclined to the mean plane through the C1–C6 benzene ring by 64.81 (12) , which is slightly less than the same dihedral angles in (II) or (III) [67.96 (7) and 68.7 , respectively].