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Acta Crystallogr Sect E Struct Rep Online. 2009 April 1; 65(Pt 4): o893–o894.
Published online 2009 March 28. doi:  10.1107/S1600536809010496
PMCID: PMC2968789

(E)-1-(4-Bromo­phen­yl)-3-(2,4,6-trimethoxy­phen­yl)prop-2-en-1-one1

Abstract

The mol­ecule of the title chalcone derivative, C18H17BrO4, is twisted, the dihedral angle between the 4-bromo­phenyl and 2,4,6-trimethoxy­phenyl rings being 39.17 (6)°. The three meth­oxy groups are oriented in two different conformations whereby two meth­oxy groups are coplanar, whereas the third is twisted with respect to the attached benzene ring [C—O—C—C torsion angles of −2.84 (18), −2.80 (18) and −9.31 (18)°]. Weak intra­molecular C—H(...)O inter­actions generate two S(5) and one S(6) ring motifs. In the crystal structure, mol­ecules are linked into supra­molecular sheets parallel to the bc plane by weak C—H(...)O inter­actions. These sheets are stacked along the a axis. The crystal structure is further stabilized by weak C—H(...)π inter­actions.

Related literature

For bond-length data, see: Allen et al. (1987 [triangle]). For hydrogen-bond motifs, see: Bernstein et al. (1995 [triangle]). For a related structure, see: Suwunwong et al. (2009 [triangle]). For background to and applications of chalcones, see: Fayed & Awad (2004 [triangle]); Jung et al. (2008 [triangle]); Patil & Dharmaprakash (2008 [triangle]); Prasad et al. (2008 [triangle]); Sens & Drexhage (1981 [triangle]) and Xu et al. (2005 [triangle]). For the stability of the temperature controller used in the data collection, see Cosier & Glazer, (1986 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-65-0o893-scheme1.jpg

Experimental

Crystal data

  • C18H17BrO4
  • M r = 377.22
  • Triclinic, An external file that holds a picture, illustration, etc.
Object name is e-65-0o893-efi1.jpg
  • a = 6.3690 (1) Å
  • b = 9.2553 (1) Å
  • c = 14.1884 (2) Å
  • α = 104.397 (1)°
  • β = 93.748 (1)°
  • γ = 98.799 (1)°
  • V = 795.88 (2) Å3
  • Z = 2
  • Mo Kα radiation
  • μ = 2.60 mm−1
  • T = 100 K
  • 0.27 × 0.20 × 0.15 mm

Data collection

  • Bruker APEXII CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2005 [triangle]) T min = 0.541, T max = 0.701
  • 16214 measured reflections
  • 4607 independent reflections
  • 4118 reflections with I > 2σ(I)
  • R int = 0.023

Refinement

  • R[F 2 > 2σ(F 2)] = 0.024
  • wR(F 2) = 0.060
  • S = 1.02
  • 4607 reflections
  • 276 parameters
  • All H-atom parameters refined
  • Δρmax = 0.42 e Å−3
  • Δρmin = −0.23 e Å−3

Data collection: APEX2 (Bruker, 2005 [triangle]); cell refinement: SAINT (Bruker, 2005 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809010496/sj2593sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809010496/sj2593Isup2.hkl

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

Acknowledgments

The authors thank Prince of Songkla University for financial support through the Crystal Materials Research Unit and Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012. TS thanks the Graduate School, Prince of Songkla University for partial financial support.

supplementary crystallographic information

Comment

Chalcones are compounds which have a wide range of applications such as in non-linear optical (Patil & Dharmaprakash, 2008) and electro-active fluorescent materials (Jung et al., 2008) or materials with various biological activities (Prasad et al., 2008). Fluorescent compounds are used for various applications such as fluorescent dyes (Fayed & Awad, 2004), light-emitting diodes, LEDs, (Sens & Drexhage, 1981) and fluorescent probes (Xu et al., 2005). In general, fluorescent materials are aromatic compounds which are conjugated with a double bond and/or aliphatic/alicyclic carbonyl groups typified by the structures of chalcone derivatives. These interesting properties prompted us to synthesize the title chalcone derivative in order to study its fluorescent properties and to compare these properties with those of a closely related structure (Suwunwong et al., 2009). We report here the crystal structure of the title compound (I).

The molecule of (I) in Fig. 1 exists in an E configuration with respect to the C8//db C9 double bond [1.3486 (18) Å]. The molecule is twisted with the interplanar angle between the 4-bromophenyl and the 2,4,6-trimethoxyphenyl rings being 39.17 (6)° compared to the corresponding angle of 44.18 (6)° between the 4-bromophenyl and the 3,4,5-trimethoxyphenyl ring in the closely related structure, 2E-1-(4-bromophenyl)-3-(3,4,5-trimethoxyphenyl) prop-2-en-1-one (II) (Suwunwong et al., 2009). Atoms O1, C6, C7 and C8 lie on the same plane with a maximum deviation of -0.001 (1) Å for atom C7 and the mean plane through them makes dihedral angles of 27.54 (7)° and 12.35 (7)° with the 4-bromophenyl and the 2,4,6-trimethoxyphenyl rings, respectively. The three methoxy groups of the 2,4,6-trimethoxyphenyl unit adopt two different orientations. The C13 and C15 methoxy groups are co-planar with the attached benzene ring with torsion angles C17–O3–C13–C12 = -2.84 (18)° and C18–O4–C15–C14 = -2.80 (18)° whereas the C11 group is twisted with a torsion angle C16–O2–C11–C12 = -9.31 (18)° indicating (-)-syn-periplanar conformations. Weak intramolecular C9—H9···O1 and C9—H9···O2 interactions generate S(5) ring motifs whereas a weak intramolecular C8—H8···O4 interaction generates an S(6) ring motif (Bernstein et al., 1995) (Table 1). The different substitutional positions of the three methoxy groups in 2,4,6-trimethoxyphenyl of (I) compared to the 3,4,5-trimethoxy groups in (II) (Suwunwong et al., 2009), produced different weak intramolecular C—H···O interactions especially the weak C9—H9···O2 and C9—H9···O4 intramolecular interactions which help the molecule of (I) to be less twisted. Bond distances in the molecule are normal (Allen et al., 1987) and are comparable with those in the closely related structure (Suwunwong et al., 2009).

In the crystal packing (Fig. 2), molecules are linked by weak intermolcular C5—H5···O3 (symmetry code: 1 + x, -1 + y, z) and C18—H18A···O1 (symmetry code: x, 1 + y, z) interactions (Table 1) into supramolecular sheets parallel to the bc plane. These sheets are stacked along the a axis. The crystal structure is further stabilized by weak C—H···π interactions (Table 1); Cg1 is the centroid of the C10–C15 ring.

Experimental

The title compound was synthesized by the condensation of 2,4,6-trimethoxybenzaldehyde (0.4 g, 2 mmol) with 4-bromoacetophenone (0.4 g, 2 mmol) in ethanol (30 ml) in the presence of 10% NaOH(aq) (5 ml). After stirring for 4 h in an ice bath (278 K), a pale yellow solid appeared after leaving the mixture at room temperature for 4 h. The resulting pale yellow solid was collected by filtration, washed with distilled water, dried and purified by repeated recrystallization from acetone. Pale yellow block-shaped single crystals of the title compound suitable for x-ray structure determination were recrystalized from acetone/ethanol (1:1 v/v) by slow evaporation of the solvent at room temperature over several days, Mp. 425–426 K.

Refinement

All H atoms were located in a difference maps and refined isotropically. Uiso = 1.2Ueq(C) for aromatic and CH and Uiso = 1.5Ueq(C) for CH3 atoms. The highest residual electron density peak is located at 0.70 Å from C15 and the deepest hole is located at 0.63 Å from C15.

Figures

Fig. 1.
The molecular structure of the title compound, with 50% probability displacement ellipsoids and the atom-numbering scheme. Intramolecular hydrogen bonds are shown as dashed lines.
Fig. 2.
The crystal packing of the title compound, showing supramolecular sheets. Hydrogen bonds are shown as dashed lines.

Crystal data

C18H17BrO4Z = 2
Mr = 377.22F(000) = 384
Triclinic, P1Dx = 1.574 Mg m3
Hall symbol: -P 1Melting point = 425–426 K
a = 6.3690 (1) ÅMo Kα radiation, λ = 0.71073 Å
b = 9.2553 (1) ÅCell parameters from 4607 reflections
c = 14.1884 (2) Åθ = 2.3–30.0°
α = 104.397 (1)°µ = 2.60 mm1
β = 93.748 (1)°T = 100 K
γ = 98.799 (1)°Block, colorless
V = 795.88 (2) Å30.27 × 0.20 × 0.15 mm

Data collection

Bruker APEXII CCD area-detector diffractometer4607 independent reflections
Radiation source: sealed tube4118 reflections with I > 2σ(I)
graphiteRint = 0.023
[var phi] and ω scansθmax = 30.0°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 2005)h = −8→8
Tmin = 0.541, Tmax = 0.701k = −13→13
16214 measured reflectionsl = −19→19

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.024Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.060All H-atom parameters refined
S = 1.02w = 1/[σ2(Fo2) + (0.029P)2 + 0.2809P] where P = (Fo2 + 2Fc2)/3
4607 reflections(Δ/σ)max = 0.001
276 parametersΔρmax = 0.42 e Å3
0 restraintsΔρmin = −0.23 e Å3

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 F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 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 (Å2)

xyzUiso*/Ueq
Br11.13952 (2)−0.293272 (16)0.461372 (11)0.02616 (5)
O10.44064 (16)−0.15866 (11)0.80334 (7)0.0216 (2)
O2−0.08941 (16)0.10051 (10)0.90599 (7)0.01977 (19)
O3−0.16385 (15)0.59990 (10)0.87549 (7)0.01789 (18)
O40.35439 (15)0.34158 (10)0.71793 (7)0.01744 (18)
C10.6621 (2)−0.08380 (15)0.59115 (10)0.0193 (2)
C20.8032 (2)−0.13463 (16)0.52476 (10)0.0213 (3)
C30.9448 (2)−0.22219 (14)0.55005 (10)0.0184 (2)
C40.9487 (2)−0.25950 (15)0.63902 (10)0.0197 (3)
C50.8037 (2)−0.21054 (14)0.70324 (10)0.0183 (2)
C60.6585 (2)−0.12259 (13)0.67994 (9)0.0153 (2)
C70.4967 (2)−0.07889 (14)0.74854 (9)0.0158 (2)
C80.4106 (2)0.06017 (14)0.74754 (9)0.0168 (2)
C90.2408 (2)0.08983 (14)0.79633 (9)0.0154 (2)
C100.13257 (19)0.21967 (13)0.81164 (9)0.0141 (2)
C11−0.0378 (2)0.22448 (13)0.87113 (9)0.0147 (2)
C12−0.1436 (2)0.34794 (14)0.89404 (9)0.0155 (2)
C13−0.0755 (2)0.47186 (14)0.85774 (9)0.0145 (2)
C140.0926 (2)0.47405 (14)0.79966 (9)0.0153 (2)
C150.19197 (19)0.34849 (13)0.77554 (9)0.0139 (2)
C16−0.2346 (2)0.10739 (16)0.97956 (10)0.0194 (3)
C17−0.3435 (2)0.60468 (16)0.93123 (10)0.0196 (3)
C180.4171 (2)0.46747 (15)0.67761 (11)0.0198 (3)
H10.562 (3)−0.026 (2)0.5736 (13)0.027 (4)*
H20.802 (3)−0.108 (2)0.4646 (14)0.029 (5)*
H41.047 (3)−0.321 (2)0.6562 (13)0.027 (4)*
H50.809 (3)−0.2327 (19)0.7633 (13)0.024 (4)*
H80.481 (3)0.1247 (19)0.7154 (12)0.017 (4)*
H90.185 (3)0.0164 (19)0.8273 (12)0.021 (4)*
H12−0.257 (3)0.3470 (19)0.9351 (13)0.022 (4)*
H140.134 (3)0.5637 (19)0.7793 (12)0.020 (4)*
H16A−0.182 (3)0.1914 (19)1.0344 (13)0.022 (4)*
H16B−0.233 (3)0.011 (2)0.9971 (14)0.030 (5)*
H16C−0.379 (3)0.1129 (18)0.9542 (12)0.016 (4)*
H17A−0.383 (3)0.700 (2)0.9308 (14)0.030 (5)*
H17B−0.455 (3)0.5210 (19)0.8990 (12)0.020 (4)*
H17C−0.302 (3)0.6012 (18)0.9976 (13)0.020 (4)*
H18A0.456 (3)0.561 (2)0.7289 (14)0.028 (5)*
H18B0.535 (3)0.444 (2)0.6459 (14)0.029 (5)*
H18C0.302 (3)0.4758 (19)0.6301 (13)0.023 (4)*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Br10.02155 (8)0.02786 (8)0.02793 (8)0.00852 (5)0.00972 (5)0.00087 (5)
O10.0250 (5)0.0186 (4)0.0258 (5)0.0072 (4)0.0092 (4)0.0105 (4)
O20.0227 (5)0.0166 (4)0.0246 (5)0.0054 (4)0.0119 (4)0.0106 (4)
O30.0185 (5)0.0176 (4)0.0220 (5)0.0089 (3)0.0091 (4)0.0081 (4)
O40.0197 (5)0.0152 (4)0.0211 (4)0.0062 (3)0.0102 (4)0.0078 (3)
C10.0199 (6)0.0216 (6)0.0183 (6)0.0097 (5)0.0017 (5)0.0053 (5)
C20.0223 (7)0.0260 (7)0.0170 (6)0.0081 (5)0.0033 (5)0.0054 (5)
C30.0158 (6)0.0168 (6)0.0204 (6)0.0033 (5)0.0036 (5)0.0002 (5)
C40.0178 (6)0.0161 (6)0.0271 (7)0.0065 (5)0.0030 (5)0.0067 (5)
C50.0196 (6)0.0161 (6)0.0213 (6)0.0046 (5)0.0031 (5)0.0076 (5)
C60.0154 (6)0.0118 (5)0.0180 (6)0.0021 (4)0.0021 (4)0.0027 (4)
C70.0168 (6)0.0140 (5)0.0164 (6)0.0031 (4)0.0018 (4)0.0030 (4)
C80.0203 (6)0.0137 (5)0.0176 (6)0.0044 (5)0.0042 (5)0.0051 (4)
C90.0171 (6)0.0131 (5)0.0158 (6)0.0022 (4)0.0013 (4)0.0039 (4)
C100.0143 (6)0.0141 (5)0.0137 (5)0.0023 (4)0.0021 (4)0.0031 (4)
C110.0155 (6)0.0137 (5)0.0149 (5)0.0012 (4)0.0019 (4)0.0049 (4)
C120.0143 (6)0.0175 (6)0.0155 (6)0.0037 (4)0.0038 (4)0.0047 (4)
C130.0143 (6)0.0149 (5)0.0149 (5)0.0047 (4)0.0011 (4)0.0036 (4)
C140.0171 (6)0.0147 (5)0.0157 (6)0.0040 (4)0.0035 (4)0.0057 (4)
C150.0135 (5)0.0151 (5)0.0132 (5)0.0027 (4)0.0030 (4)0.0036 (4)
C160.0197 (6)0.0206 (6)0.0203 (6)0.0026 (5)0.0082 (5)0.0087 (5)
C170.0172 (6)0.0228 (6)0.0212 (6)0.0076 (5)0.0070 (5)0.0061 (5)
C180.0229 (7)0.0165 (6)0.0244 (7)0.0062 (5)0.0125 (5)0.0093 (5)

Geometric parameters (Å, °)

Br1—C31.8963 (13)C8—H80.920 (17)
O1—C71.2321 (15)C9—C101.4524 (17)
O2—C111.3627 (14)C9—H90.936 (17)
O2—C161.4351 (15)C10—C111.4171 (17)
O3—C131.3634 (15)C10—C151.4205 (16)
O3—C171.4326 (16)C11—C121.3943 (17)
O4—C151.3591 (14)C12—C131.3927 (17)
O4—C181.4364 (15)C12—H120.957 (18)
C1—C21.3910 (19)C13—C141.3937 (17)
C1—C61.3939 (18)C14—C151.3870 (17)
C1—H10.953 (18)C14—H140.950 (17)
C2—C31.388 (2)C16—H16A0.953 (18)
C2—H20.943 (19)C16—H16B0.985 (19)
C3—C41.3888 (19)C16—H16C0.980 (17)
C4—C51.3858 (19)C17—H17A0.956 (18)
C4—H40.965 (18)C17—H17B0.961 (17)
C5—C61.3969 (18)C17—H17C0.971 (17)
C5—H50.924 (18)C18—H18A0.971 (19)
C6—C71.4954 (17)C18—H18B0.93 (2)
C7—C81.4768 (17)C18—H18C0.987 (18)
C8—C91.3486 (18)
C11—O2—C16118.40 (10)O2—C11—C12122.08 (11)
C13—O3—C17118.06 (10)O2—C11—C10115.23 (11)
C15—O4—C18117.90 (10)C12—C11—C10122.69 (11)
C2—C1—C6121.15 (12)C13—C12—C11118.12 (11)
C2—C1—H1118.8 (11)C13—C12—H12121.9 (10)
C6—C1—H1120.0 (11)C11—C12—H12120.0 (10)
C3—C2—C1118.35 (13)O3—C13—C12123.91 (11)
C3—C2—H2121.6 (11)O3—C13—C14114.39 (11)
C1—C2—H2120.1 (11)C12—C13—C14121.70 (11)
C2—C3—C4121.82 (13)C15—C14—C13119.29 (11)
C2—C3—Br1119.49 (10)C15—C14—H14123.6 (10)
C4—C3—Br1118.70 (10)C13—C14—H14117.1 (10)
C5—C4—C3118.94 (12)O4—C15—C14122.54 (11)
C5—C4—H4119.5 (11)O4—C15—C10115.72 (10)
C3—C4—H4121.5 (11)C14—C15—C10121.72 (11)
C4—C5—C6120.70 (12)O2—C16—H16A110.1 (11)
C4—C5—H5118.9 (11)O2—C16—H16B102.7 (11)
C6—C5—H5120.4 (11)H16A—C16—H16B110.8 (15)
C1—C6—C5119.01 (12)O2—C16—H16C112.1 (10)
C1—C6—C7121.73 (11)H16A—C16—H16C110.4 (14)
C5—C6—C7119.20 (11)H16B—C16—H16C110.5 (14)
O1—C7—C8122.63 (12)O3—C17—H17A103.5 (11)
O1—C7—C6119.49 (11)O3—C17—H17B108.7 (10)
C8—C7—C6117.87 (11)H17A—C17—H17B112.0 (15)
C9—C8—C7119.33 (11)O3—C17—H17C110.5 (10)
C9—C8—H8123.4 (10)H17A—C17—H17C110.8 (15)
C7—C8—H8117.2 (10)H17B—C17—H17C111.1 (14)
C8—C9—C10130.75 (12)O4—C18—H18A111.0 (11)
C8—C9—H9115.1 (11)O4—C18—H18B104.2 (11)
C10—C9—H9114.1 (11)H18A—C18—H18B110.1 (15)
C11—C10—C15116.44 (11)O4—C18—H18C110.9 (10)
C11—C10—C9118.69 (11)H18A—C18—H18C110.4 (15)
C15—C10—C9124.78 (11)H18B—C18—H18C110.0 (15)
C6—C1—C2—C3−1.6 (2)C15—C10—C11—O2−179.05 (11)
C1—C2—C3—C40.0 (2)C9—C10—C11—O2−2.38 (17)
C1—C2—C3—Br1−179.94 (10)C15—C10—C11—C12−0.09 (18)
C2—C3—C4—C51.4 (2)C9—C10—C11—C12176.58 (12)
Br1—C3—C4—C5−178.66 (10)O2—C11—C12—C13177.93 (11)
C3—C4—C5—C6−1.2 (2)C10—C11—C12—C13−0.96 (19)
C2—C1—C6—C51.8 (2)C17—O3—C13—C12−2.84 (18)
C2—C1—C6—C7−175.19 (12)C17—O3—C13—C14177.45 (11)
C4—C5—C6—C1−0.4 (2)C11—C12—C13—O3−179.38 (11)
C4—C5—C6—C7176.71 (12)C11—C12—C13—C140.31 (19)
C1—C6—C7—O1151.49 (13)O3—C13—C14—C15−178.89 (11)
C5—C6—C7—O1−25.51 (18)C12—C13—C14—C151.40 (19)
C1—C6—C7—C8−28.65 (18)C18—O4—C15—C14−2.80 (18)
C5—C6—C7—C8154.35 (12)C18—O4—C15—C10178.51 (11)
O1—C7—C8—C9−10.8 (2)C13—C14—C15—O4178.88 (11)
C6—C7—C8—C9169.35 (12)C13—C14—C15—C10−2.52 (19)
C7—C8—C9—C10176.36 (12)C11—C10—C15—O4−179.45 (10)
C8—C9—C10—C11−176.74 (13)C9—C10—C15—O44.10 (18)
C8—C9—C10—C15−0.4 (2)C11—C10—C15—C141.86 (18)
C16—O2—C11—C12−9.31 (18)C9—C10—C15—C14−174.59 (12)
C16—O2—C11—C10169.65 (11)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
C5—H5···O3i0.925 (18)2.497 (18)3.3572 (17)154.9 (15)
C8—H8···O40.920 (18)2.268 (18)2.8103 (16)117.2 (14)
C9—H9···O10.936 (18)2.449 (19)2.8128 (17)103.1 (13)
C9—H9···O20.936 (18)2.269 (19)2.6960 (16)107.1 (14)
C18—H18A···O1ii0.968 (19)2.566 (19)3.4518 (18)152.1 (15)
C17—H17C···Cg1iii0.971 (17)2.754 (18)3.6601 (14)155.6 (14)

Symmetry codes: (i) x+1, y−1, z; (ii) x, y+1, z; (iii) −x, −y+1, −z+2.

Footnotes

1This paper is dedicated to the late Her Royal Highness Princess Galyani Vadhana Krom Luang Naradhiwas Rajanagarindra for her patronage of Science in Thailand.

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: SJ2593).

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