(2E)-3-(4-Bromophenyl)-1-(4,4′′-difluoro-5′-methoxy-1,1′:3′,1′′-terphenyl-4′-yl)prop-2-en-1-one

In the title compound, C28H19BrF2O2, the C=C double bond is E-configured. In the crystal, C—H⋯O and C—H⋯F contacts connect molecules into planes perpendicular to the c axis. The shortest centroid–centroid distance between two aromatic systems is 3.6745 (12) Å between one of the para-fluorophenyl rings and its symmetry-generated equivalent.

In the title compound, C 28 H 19 BrF 2 O 2 , the C C double bond is E-configured. In the crystal, C-HÁ Á ÁO and C-HÁ Á ÁF contacts connect molecules into planes perpendicular to the c axis. The shortest centroid-centroid distance between two aromatic systems is 3.6745 (12) Å between one of the parafluorophenyl rings and its symmetry-generated equivalent.

Hosten and Richard Betz Comment
The synthesis of polysubstituted aromatics has been and is a fascinating area in the field of organic chemistry (Astrue, 2002). In recent years, it has been reported that some terphenyls exhibit considerable biological activities such as anticoagulant, immunosuppressant, antithrombotic, neuroprotective, specific 5-lipoxygenase inhibitory and cytotoxic activities (Liu, 2006). Recently, the crystal structures of several terphenyl derivatives have been reported (Fun et al., 2012a,b,c,d,e;Betz et al., 2011a,b,c,d,e). In continuation of our ongoing interest in terphenyl derivatives, the title compound was prepared and its crystal structure determined.
The C=C double of the Michael system is (E)-configured. The least-squares planes defined by the carbon atoms of the para-fluoro phenyl rings of the terphenyl moiety and its central phenyl ring enclose angles of 41.74 (9)° and 46.49 (9)°, respectively ( Fig. 1).
In the crystal structure, C-H···O as well as C-H···F contacts are present whose range falls by up to 0.2 Å below the sum of van-der-Waals radii of the atoms participating in them. While the C-H···O contacts are apparent between the ketonic oxygen atom and one of the para-fluorophenyl-bonded hydrogen atoms, the C-H···F contacts are supported by one of the hydrogen atoms of the methoxy substituent on the terphenyl's central phenyl group. In terms of graph-set analysis (Etter et al., 1990;Bernstein et al., 1995), the C-H···O contacts necessitate a C 1 1 (10) descriptor on the unitary level and the C-H···F contacts necessitate a C 1 1 (11) descriptor on the same level. These two antidromic chains connect the molecules to planes perpendicular to the crystallographic c axis. Details about metrical parameters of these contacts as well as information about their symmetry can be found in Table 1. The shortest intercentroid distance between two aromatic systems was found at 3.6745 (12) Å and is apparent between one of the para-fluoro phenyl moieties and its symmetrygenerated equivalent (Fig. 2).

Refinement
Carbon-bound H atoms were placed in calculated positions (C-H 0.95 Å for aromatic and vinylic carbon atoms) and were included in the refinement in the riding model approximation, with U(H) set to 1.2U eq (C). The H atoms of the supplementary materials sup-2 Acta Cryst. (2012). E68, o3433-o3434 methyl groups were allowed to rotate with a fixed angle around the C-C bond to best fit the experimental electron density (HFIX 137 in the SHELX program suite (Sheldrick, 2008)), with U(H) set to 1.5U eq (C).