5-(4-Bromophenyl)-3-(4-fluorophenyl)-1-phenyl-4,5-dihydro-1H-pyrazole

In the title compound, C21H16BrFN2, the fluoro-substituted benzene ring is disordered over two orientations about the C—F bond and the C—C bond between the benzene and pyrazole groups with a site-occupancy ratio of 0.516 (8):0.484 (8). The central pyrazole ring [maximum deviation = 0.035 (3) Å] makes dihedral angles of 22.4 (2), 11.0 (2), 77.19 (16) and 7.44 (17)° with the two disorder components of the benzene ring, the bromo-substituted benzene ring and the phenyl ring, respectively. In the crystal, molecules are linked into a layer parallel to the bc plane through C—H⋯π interactions.

In the title compound, C 21 H 16 BrFN 2 , the fluoro-substituted benzene ring is disordered over two orientations about the C-F bond and the C-C bond between the benzene and pyrazole groups with a site-occupancy ratio of 0.516 (8):0.484 (8). The central pyrazole ring [maximum deviation = 0.035 (3) Å ] makes dihedral angles of 22.4 (2), 11.0 (2), 77.19 (16) and 7.44 (17) with the two disorder components of the benzene ring, the bromo-substituted benzene ring and the phenyl ring, respectively. In the crystal, molecules are linked into a layer parallel to the bc plane through C-HÁ Á Á interactions.
Cg1 is the centroid of the C10-C15 ring. Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009  In continuation of our work on synthesis of pyrazoline derivatives (Fun et al., 2010;Samshuddin et al., 2010Samshuddin et al., , 2011, the title compound was prepared and its crystal structure is now reported. The asymmetric unit of the title compound is shown in Fig. 1 lengths and angles are comparable to those found in a related structure . In the crystal, molecules are linked into a layer parallel to (100) through intermolecular C-H···π interactions (Table 1), involving Cg1 which is the centroid of the C10-C15 ring.

Refinement
All H atoms were positioned geometrically (C-H = 0.95, 0.99 and 1.00 Å) and refined using a riding model with U iso (H) = 1.2U eq (C). The fluoro-substituted benzene ring is statistically disordered over two conformations with a site-occupancy ratio of 0.516 (8):0.484 (8). Similarity (SAME), similar-ADP (SIMU) and FLAT restraints were used for the major and minor components of disordered fluoro-substituted benzene ring (C16-C21 and C16/C17X/C18X/C19/C20X/C21X). The highest peak is located at 0.31 Å from atom C17, whereas the deepest hole is located at 0.34 Å from atom C21.

Computing details
Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009   The molecular structure of the title compound with atom labels with 50% probability displacement ellipsoids. The minor component of disorder is indicated by the open bonds. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 1.26 e Å −3 Δρ min = −0.99 e Å −3 Special details Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K. Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq Occ. (