(2E)-1-(4-Bromo­phen­yl)-3-(4-fluoro­phen­yl)prop-2-en-1-one

Grzegorz Dutkiewicz; K Veena; B Narayana; H S Yathirajan; Maciej Kubicki

doi:10.1107/S1600536810015485

. 2010 Apr 30;66(Pt 5):o1243–o1244. doi: 10.1107/S1600536810015485

(2E)-1-(4-Bromophenyl)-3-(4-fluorophenyl)prop-2-en-1-one

Grzegorz Dutkiewicz ^a, K Veena ^b, B Narayana ^b, H S Yathirajan ^c, Maciej Kubicki ^a,^*

PMCID: PMC2979273 PMID: 21579262

Abstract

The title compound, C₁₅H₁₀BrFO, is isostructural with (2E)-1-(4-chlorophenyl)-3-(4-fluorophenyl)prop-2-en-1-one [Qiu et al. (2006 ▶). Acta Cryst. E62, o3525–o3526], but the structures of other dihalogen analogues, without fluorine, are different, although they are also isostructural within the series. The molecule is approximately flat, the dihedral angle between the ring planes being 8.49 (13)°. In the crystal structure, intermolecular C—H⋯O, C—H⋯F and C—H⋯Br hydrogen bonds link molecules into V-shaped ribbons running parallel to [101] and stacked with an interplanar distance of approximately 3.53 Å (centroid–vcentroid distance = 3.857 Å)..

Related literature

For general background to chalcones, see: Dhar (1981 ▶); Goto et al. (1991 ▶); Uchida et al. (1998 ▶); Indira et al. (2002 ▶); Sarojini et al. (2006 ▶). For a description of the Cambridge Structural Database, see: Allen (2002 ▶). For the isostructurality index, see: Kálmán et al. (1991 ▶). For related halogen derivatives, see: Ng, Razak, et al. (2006 ▶); Ng, Shettigar et al. (2006 ▶); Qiu et al. (2006 ▶); Wang et al. (2005 ▶); Yang et al. (2006 ▶).

Experimental

Crystal data

C₁₅H₁₀BrFO
M _r = 305.14
Monoclinic,
a = 4.0060 (5) Å
b = 23.1253 (12) Å
c = 13.4933 (9) Å
β = 96.344 (6)°
V = 1242.36 (19) Å³
Z = 4
Cu Kα radiation
μ = 4.49 mm⁻¹
T = 295 K
0.4 × 0.2 × 0.1 mm

Data collection

Oxford Diffraction SuperNova (single source at offset) Atlas diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009 ▶) T _min = 0.386, T _max = 1.000
4548 measured reflections
2435 independent reflections
2299 reflections with I > 2σ(I)
R _int = 0.018

Refinement

R[F ² > 2σ(F ²)] = 0.043
wR(F ²) = 0.116
S = 1.12
2435 reflections
203 parameters
All H-atom parameters refined
Δρ_max = 0.73 e Å⁻³
Δρ_min = −0.50 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR92 (Altomare et al., 1993 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XP (Siemens, 1989 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810015485/rz2439sup1.cif

e-66-o1243-sup1.cif^{(16.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810015485/rz2439Isup2.hkl

e-66-o1243-Isup2.hkl^{(117.2KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C7—H7⋯O9ⁱ	0.98 (3)	2.62 (3)	3.512 (3)	151 (2)
C3—H3⋯O9ⁱ	0.99 (3)	2.41 (3)	3.358 (3)	160 (2)
C15—H15⋯Br1ⁱⁱ	1.02 (3)	2.92 (3)	3.845 (2)	151 (2)
C12—H12⋯F1ⁱⁱⁱ	1.00 (3)	2.55 (3)	3.351 (3)	137 (2)

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

BN thanks the UGC, New Delhi, Government of India, for the purchase of chemicals through the SAP-DRS-Phase 1 programme.

supplementary crystallographic information

Comment

Chalcones or 1,3-diaryl-2-propen-1-ones (Ar—CH=CH—CO—Ar) are one of the major classes of natural products with widespread distribution in fruits, vegetables, spices, tea and soy based foodstuff. These compounds have been recently subjects of great interest for their interesting pharmacological activities (Dhar, 1981). They are finding application as organic nonlinear optical materials (NLO) for their SHG conversion efficiency (Sarojini et al., 2006). Among several organic compounds reported which have NLO properties, chalcones derivatives are recognized material because of their excellent blue light transmittance and good crystallization ability (Goto et al., 1991; Uchida et al. (1998); Indira et al., 2002).

In the Cambridge Structural Database (Allen, 2002; Version 5.31, Nov. 2009) there are structural data for a series of the (2E)-1-(4-X)-3-(4-Y)prop-2-en-1-ones (X, Y - halogen). Those which have chloro- and/or bromo-substituents (X = Y = Cl: Wang et al., 2005; X = Cl, Y = Br: Ng, Razak et al., 2006; X = Y = Br: Ng, Shettigar et al., 2006, and X = Br, Y = Cl: Yang et al., 2006) are isostructural (P2₁/c space group), and their crystal structure is similarly organized by π–π and halogen–halogen interactions. The only fluoro-derivative in the CCDC, (E)-1-(4-chlorophenyl)-3-(4-fluorophenyl)prop-2-en-1-one (i.e. X = Cl, Y = F, Qiu et al., 2006) does not fit into this scheme; although it crystallizes in the same space group, however in different setting (P2₁/n), both the molecular geometry and the crystal packing are different. Here we present the crystal structure of another fluoro-derivative, (2E)-1-(4-bromophenyl)-3-(4-fluorophenyl)prop-2-en-1-one (I, Scheme 1), which turned out to be isostructural with the latter example.

The crystal structure of I is isostructural with the F-Cl analogue; both compounds crystallize in the P2₁/n space group and their crystal packings are almost identical. The isostructurality index (Kálmán et al., 1991), which measures the differences in the positions of the atoms in the respective unit cell, is 0.9%, which is very close to the ideal value of 0.

The molecule of I is approximately planar (Fig. 1), the dihedral angle between the planes of the aromatic rings is 8.49 (13)°, and the central C=C-C=O fragment, is inclined by about 10° with respect to both rings. This conformation is of course similar to the F-Cl analogue, where the terminal planes make a angle of 9.1°, but is essentially different from the other group of halogeno- derivatives, where the conformation is much more folded, the dihedral angles being around 45°. It might be noted that there is also another difference: in the latter structures the angles between the central plane and the ring planes approximately sum up to the value of the angle between terminal planes. That means that in these cases the rings are twisted in opposite directions with respect to the central plane, while in I they are twisted in the same direction.

In the crystal structure, the molecules are connected by means of weak C—H···O hydrogen bonds into centrosymmetric dimers, and these dimers are connected by weak C—H···F interactions into two-molecule wide ribbons (Fig. 2). Neighbouring ribbons, inclined by an angle of approximately 58°, are connected by C—H···Br contacts (Fig. 3). In spite of the compounds without fluorine, there are no short halogen···halogen contacts. This might be regarded as another evidence of the essential difference between fluorine and other halogen atoms.

Additionally, thanks to the short unit cell parameter of 4.0060 (5)Å, the planes of molecules are stacked one onto another with an interplanar distance of about 3.53Å.

Experimental

10 ml of 10% KOH was added to a mixture of 4-bromoacetophenone (0.01 mol) and p-fluorobenzaldehyde (0.01 mol) in 40 mL of ethyl alcohol. The reaction mixture was then kept under constant stirring. The solid product was filtered and recrystallized from an ethyl acetate solution at room temperature. C₁₅H₁₀BrFO, calculated: C 59.04% 3.30%, found: C 58.98, H 3.25. M.P.: 362-366 K.