(E)-3-(Biphenyl-4-yl)-1-(3-bromo­phen­yl)prop-2-en-1-one

Grzegorz Dutkiewicz; C S Chidan Kumar; H S Yathirajan; B Narayana; Maciej Kubicki

doi:10.1107/S1600536809043384

. 2009 Oct 28;65(Pt 11):o2856–o2857. doi: 10.1107/S1600536809043384

(E)-3-(Biphenyl-4-yl)-1-(3-bromophenyl)prop-2-en-1-one

Grzegorz Dutkiewicz ^a, C S Chidan Kumar ^b, H S Yathirajan ^b, B Narayana ^c, Maciej Kubicki ^a,^*

PMCID: PMC2971314 PMID: 21578444

Abstract

In the title compound, C₂₁H₁₅BrO, there are two planar rings connected through a conjugated double bond. As it crystallizes in a non-centrosymmetric space group it can be regarded as a good candidate for non-linear optical applications. The molecule adopts an E configuration and the C—C=C—C torsion angle is 177.1 (4)°. The overall conformation of the compound may be described by the values of dihedral angles between the approximately planar parts. The terminal rings are twisted by an angle of 51.52 (9)°, while the biphenyl part is almost planar, the dihedral angle between the planes of the rings being 4.44 (17)°. The unit cell has one long dimension, above 35 Å, characteristic also of a majority of related compounds. The molecules pack head-to-tail along this direction. C—H⋯π interactions are observed in the crystal structure.

Related literature

For applications of chalcones, see: Cho et al. (1996 ▶); Dinkova-Kostova et al., (1998 ▶); Fichou et al. (1988 ▶); Liu et al. (2003 ▶); Nielson et al. (1998 ▶); Rajas et al. (2002 ▶); Sarojini et al. (2006 ▶). For related structures, see: Fischer et al. (2007a ▶,b ▶,c ▶); Moorthi et al. (2007 ▶); Sarojini et al. (2007 ▶).

Experimental

Crystal data

C₂₁H₁₅BrO
M _r = 363.24
Orthorhombic,
a = 6.092 (1) Å
b = 7.295 (1) Å
c = 36.619 (2) Å
V = 1627.4 (4) Å³
Z = 4
Mo Kα radiation
μ = 2.53 mm⁻¹
T = 295 K
0.4 × 0.2 × 0.2 mm

Data collection

Oxford Diffraction Xcalibur Sapphire2 (large Be window) diffractometer
Absorption correction: multi-scan (CrysAlis Pro; Oxford Diffraction, 2006 ▶) T _min = 0.632, T _max = 1.000
5236 measured reflections
2766 independent reflections
2209 reflections with I > 2σ(I)
R _int = 0.022

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.085
S = 1.05
2766 reflections
208 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.45 e Å⁻³
Absolute structure: Flack (1983 ▶), 1133 Friedel pairs
Flack parameter: 0.059 (11)

Data collection: CrysAlis Pro (Oxford Diffraction, 2006 ▶); cell refinement: CrysAlis Pro; data reduction: CrysAlis Pro; program(s) used to solve structure: SIR92 (Altomare et al., 1994 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: Stereochemical Workstation Operation Manual (Siemens, 1989 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809043384/nk2009sup1.cif

e-65-o2856-sup1.cif^{(18.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809043384/nk2009Isup2.hkl

e-65-o2856-Isup2.hkl^{(133KB, 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
C3—H3⋯Cg1ⁱ	0.93	2.85	3.583 (5)	137
C6—H6⋯Cg1ⁱⁱ	0.93	2.78	3.516 (5)	137
C9—H9⋯Cg2ⁱ	0.93	2.87	3.544 (5)	131
C12—H12⋯Cg2ⁱⁱ	0.93	2.97	3.655 (5)	131
C21—H21⋯Cg3ⁱⁱⁱ	0.93	2.83	3.505 (5)	131

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) . Cg1, Cg2 and Cg3 are the centroids of the C1–C6, C7–C12 and C17–C22 rings, respectively.

Acknowledgments

CSC thanks the University of Mysore for research facilities.

supplementary crystallographic information

Comment

For such a structurally simple group of compounds, chalcones have displayed an impressive array of biological activities, among which antimalarial (Liu et al., 2003), antiprotozoal (Nielson et al., 1998), nitric oxide inhibition (Rajas et al., 2002) and anticancer (Dinkova-Kostova et al., 1998) activities have been cited in the literature. Also, among organic compounds reported for non-linear optical (NLO) properties, chalcone derivatives are notable materials for their excellent blue-light transmittance and good crystallizability. They provide the necessary configuration to show NLO properties, with two planar rings connected through a conjugated double bond (e.g., Sarojini et al., 2006). Substitution on either of the benzene rings greatly influences the non-centrosymmetric crystal packing. It is speculated that, in order to improve the activity, more bulky substituents should be introduced to increase the spontaneous polarization of non-centrosymmetric crystals (Fichou et al., 1988). The molecular hyperpolarizability is strongly influenced, not only by the electronic effect, but also by the steric effect of the substituent (Cho et al., 1996). Prompted by this, and in a continuation of our quest to synthesize new materials which can find use in the photonics industry, we have synthesized new chalcones and studied their SHG (second harmonic generation) efficiency.

(2E)-3-(biphenyl-4-yl)-1-(3-bromophenyl)prop-2-en-1-one (I) crystallizes in the non-centrosymmetric space group Pca2₁, which makes NLO activity possible. The overall conformation of the molecule can be described by the dihedral angles between the planar fragments: two rings of biphenyl system (A and B, cf. Fig. 1), the enone fragment (C) and the (bromo)phenyl ring (D). All these fragments are in a good approximation planar (maximum deviation from the least-squares plane is 0.018 (4)Å for the enone fragment). The biphenyl rings are almost coplanar, the dihedral angle between them is 4.44 (17)°; the enone fragment is significantly inclined with respect to both neighbouring rings, B/C angle is 30.74 (11)° and C/D - 16.34 (12)°.

The conformation for the ketone system is s–cis, as evidenced by the torsion angle O16—C15— C14—C13 of -21.7 (6)°. In general, the conformation of the molecule (I) is similar to the related compounds (e.g., Fischer et al., 2007a, b, c, Moorthi et al., 2007).

The unit cell of (I) has a long c axis of 36.619 (2) Å, and the molecules pack head-to-tail along this direction (Fig. 2). Such a long unit-cell parameter is observed in a number of similar compounds, even though they crystallize in different space groups and even in different crystal classes. For instance, 4-bromo (Fischer et al., 2007b), 4-chloro (Fischer et al., 2007a) and 4-methoxyphenyl (Fischer et al., 2007c) analogues crystallize all in the Cc space groups with the long parameter (ca. 36 Å) along c-direction, 4-fluoro derivative (Sarojini et al., 2007) - in P2₁ space group (Z' = 2) with the long b direction etc. It might be also noted, that other unit-cell parameters in all these structures are also similar to those observed in (I), and the comparison of the packing modes shows a significant degree of isostructurality. This suggests that the same interactions are responsible for the crystal packing in these structures: these can be some relatively short and linear C—H···π contacts, and van der Waals interactions.

Experimental

5 ml 40% KOH solution was added to a thoroughly stirred solution of 3-bromoacetophenone (1.0 g, 5 m mol) and 4-biphenylcarboxaldehyde (1.0 g, 5.4 m mol) in 15 ml of methanol. The mixture was stirred overnight and filtered. The product formed was crystallized in methanol. X-ray quality crystals were grown from slow evaporation of ethyl acetate solution (m.p.: 378 – 380 K).