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

In the meta-terphenyl fragment of the title molecule, C29H22F2O2, the two fluorophenyl rings are twisted from the central benzene ring by 46.72 (6) and 41.70 (6)°, respectively. In the crystal, weak C—H⋯O and C—H⋯F hydrogen bonds link the molecules into layers parallel to the ab plane. The crystal packing exhibits π–π interactions, the shortest distance between the centroids of aromatic rings being 3.6364 (7) Å.

In the meta-terphenyl fragment of the title molecule, C 29 H 22 F 2 O 2 , the two fluorophenyl rings are twisted from the central benzene ring by 46.72 (6) and 41.70 (6) , respectively. In the crystal, weak C-HÁ Á ÁO and C-HÁ Á ÁF hydrogen bonds link the molecules into layers parallel to the ab plane. The crystal packing exhibitsinteractions, the shortest distance between the centroids of aromatic rings being 3.6364 (7) Å .

Comment
In view of pharmacological importance of terphenyls (Liu, 2006) and chalcones, and in continuation of our works on the synthesis of various derivatives of 4,4'-difluoro chalcone (Samshuddin et al., 2011a,b;Fun et al., 2010a,b;Jasinski et al., 2010a,b;Baktir et al., 2011a,b), the molecular and crystal structure of the title compound (I) is reported.
In (I) (Fig. 1), 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 41.70 (6)° and 46.72 (6)°, respectively.
In the crystal structure, intermolecular C-H···O and C-H···F contacts are present (Table 1). While the C-H···O contacts are apparent between the ketonic oxygen atom and one of the phenyl-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. The shortest intercentroid distance between two aromatic systems was found at 3.6364 (7) Å and is apparent between one of the para-fluoro phenyl moieties and its symmetry-generated equivalent. The packing of the title compound in the crystal structure is shown in Figure 2.
Single crystals suitable for the X-ray diffraction study were grown from DMF by slow evaporation at room temperature.

Refinement
C-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 iso (H) set to 1.2U eq (C). The H atoms of the 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 iso (H) set to 1.5U eq (C). Fig. 1. The molecular structure of (I) with atomic labels and anisotropic displacement ellipsoids (drawn at 50% probability level).