(2E,2′E)-1,1′-Bis(4-chloro­phen­yl)-3,3′-(1,4-phenyl­ene)diprop-2-en-1-one

In the centrosymmetric title compound, C₂₄H₁₆Cl₂O₂, the dihedral angle between the central and terminal benzene rings is 46.27 (9)°. Edge-to-face C—H...π inter­actions are observed, with H...centroid distances in the range 2.70–2.83 Å. Cl...Cl contacts of 3.3701 (14) Å are also present.

Key indicators

• Single-crystal X-ray study
• T = 120 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.061
• wR factor = 0.200
• Data-to-parameter ratio = 13.7

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT029_ALERT_3_B _diffrn_measured_fraction_theta_full Low .......       0.94

Alert level C
REFLT03_ALERT_3_C  Reflection count < 95% complete
           From the CIF: _diffrn_reflns_theta_max           25.99
           From the CIF: _diffrn_reflns_theta_full          25.99
           From the CIF: _reflns_number_total               1739
           TEST2: Reflns within _diffrn_reflns_theta_max
           Count of symmetry unique reflns         1851
           Completeness (_total/calc)             93.95%
PLAT022_ALERT_3_C Ratio Unique / Expected Reflections too Low ....       0.94
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          5

   0 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   4 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

As part of our ongoing studies of organic nonlinear optical materials derived from substituted chalcones (Harrison et al., 2007a,b), we report here the synthesis and structure of the title compound (Fig. 1).

The molecule is centrosymmetric and the dihedral angle between the mean planes of the central C1–C3/C1ⁱ–C3ⁱ [symmetry code: (i) -x, 1 - y, -z] and pendant C7–C12 benzene rings is 46.27 (9)°. The linking enone (C4/C5/C6/O1) fragment is substantially twisted, with a torsion angle of -19.3 (5)°.

In the crystal, the molecules lie in sheets in the (100) planes, with C—H···π interactions observed between molecules (Table 1, Figs. 2 and 3). Inter-sheet Cl1···Cl1ⁱⁱ contacts [symmetry code: (ii) 1 - x, 1 - y, -z] of 3.3701 (14) Å are formed, which are slightly short compared to the expected van der Waals separation of 3.50 Å.

Related literature

For related structures, see: Harrison et al. (2007a,b).

S2. Experimental

A mixture of methanol (25 ml) and 10% aqueous NaOH (5 ml) solution were taken in a conical flask. A previously prepared small portion of terephthalaldehyde (0.001 mol) and 1-(4-chlorophenyl)ethanone (0.002 mol) dissolved in methanol was added to the conical flask with stirring and the temperature of the solution was maintained between 298 and 303 K. A precipitate was obtained after stirring the solution for about five minutes. The remaining portion of the aldehyde and ketone mixture was added and the solution was stirred for a further 60 minutes. The separated product was filtered, washed with water and dried. The resulting compound was purified by recrystallization from DMF. Single crystals used for X-ray diffraction analysis were grown by slow evaporation of a DMF solution.

S3. Refinement

H atoms were placed in calculated positions (C—H = 0.95 Å) and refined as riding with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: COLLECT (Nonius, 1998); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: SCALEPACK and DENZO (Otwinowski & Minor, 1997), and SORTAV (Blessing, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The molecular structure of the title compound showing 50% displacement ellipsoids (H atoms are drawn as spheres of arbitrary radius). Symmetry code: (i) -x, 1 - y, -z.
	Fig. 2. Partial packing diagram showing the C—H···π interactions as dashed lines.
	Fig. 3. Unit-cell packing viewed down [010] with H atoms omitted for clarity.

(2E,2'E)-1,1'-Bis(4-chlorophenyl)-3,3'-(1,4-phenylene)diprop- 2-en-1-one

Crystal data

C24H16Cl2O2	F(000) = 420
Mr = 407.26	Dx = 1.438 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 8003 reflections
a = 22.9779 (19) Å	θ = 2.9–27.5°
b = 7.0369 (5) Å	µ = 0.36 mm^−1
c = 5.8425 (5) Å	T = 120 K
β = 95.229 (3)°	Plate, pale yellow
V = 940.76 (13) Å^3	0.24 × 0.12 × 0.02 mm
Z = 2

Data collection

Nonius KappaCCD area-detector diffractometer	1739 independent reflections
Radiation source: fine-focus sealed tube	1556 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.035
ω and φ scans	θmax = 26.0°, θmin = 3.0°
Absorption correction: multi-scan (SADABS; Bruker, 2003)	h = −28→28
Tmin = 0.918, Tmax = 0.993	k = −8→8
6340 measured reflections	l = −7→7

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.061	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.200	H-atom parameters constrained
S = 1.16	w = 1/[σ^2(Fo^2) + (0.0964P)^2 + 1.6678P] where P = (Fo^2 + 2Fc^2)/3
1739 reflections	(Δ/σ)max < 0.001
127 parameters	Δρmax = 0.43 e Å^−3
0 restraints	Δρmin = −0.45 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
C1	−0.00124 (14)	0.4218 (4)	0.2158 (5)	0.0217 (7)
H1	−0.0022	0.3663	0.3636	0.026*
C2	0.05237 (13)	0.4808 (4)	0.1436 (5)	0.0200 (7)
C3	0.05293 (14)	0.5572 (4)	−0.0756 (6)	0.0220 (7)
H3	0.0889	0.5952	−0.1298	0.026*
C4	0.10477 (14)	0.4691 (4)	0.3076 (6)	0.0229 (7)
H4	0.0995	0.4224	0.4569	0.027*
C5	0.15882 (14)	0.5176 (4)	0.2671 (6)	0.0237 (7)
H5	0.1668	0.5538	0.1164	0.028*
C6	0.20686 (15)	0.5159 (4)	0.4554 (6)	0.0246 (7)
C7	0.26819 (14)	0.5103 (4)	0.3861 (6)	0.0217 (7)
C8	0.28095 (14)	0.4390 (4)	0.1750 (6)	0.0241 (7)
H8	0.2501	0.4002	0.0659	0.029*
C9	0.33836 (15)	0.4239 (5)	0.1218 (6)	0.0264 (7)
H9	0.3471	0.3707	−0.0205	0.032*
C10	0.38278 (14)	0.4877 (5)	0.2800 (6)	0.0249 (7)
C11	0.37131 (15)	0.5624 (5)	0.4894 (6)	0.0282 (8)
H11	0.4023	0.6067	0.5947	0.034*
C12	0.31431 (15)	0.5719 (4)	0.5438 (6)	0.0256 (7)
H12	0.3060	0.6205	0.6891	0.031*
O1	0.19730 (10)	0.5193 (4)	0.6579 (4)	0.0313 (6)
Cl1	0.45434 (4)	0.47454 (16)	0.20782 (17)	0.0420 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0257 (15)	0.0183 (14)	0.0209 (15)	−0.0002 (12)	0.0004 (12)	−0.0028 (12)
C2	0.0198 (14)	0.0192 (14)	0.0208 (15)	0.0006 (11)	0.0013 (11)	−0.0028 (12)
C3	0.0188 (14)	0.0203 (14)	0.0270 (16)	−0.0026 (11)	0.0024 (12)	−0.0008 (12)
C4	0.0239 (16)	0.0223 (15)	0.0215 (16)	0.0013 (12)	−0.0025 (13)	−0.0004 (12)
C5	0.0237 (16)	0.0262 (16)	0.0207 (16)	0.0030 (12)	−0.0012 (12)	0.0022 (13)
C6	0.0254 (16)	0.0203 (15)	0.0272 (18)	0.0025 (12)	−0.0034 (13)	−0.0014 (13)
C7	0.0215 (15)	0.0190 (14)	0.0235 (16)	0.0025 (12)	−0.0044 (12)	0.0021 (12)
C8	0.0244 (16)	0.0216 (15)	0.0250 (17)	0.0006 (12)	−0.0047 (13)	−0.0020 (13)
C9	0.0280 (17)	0.0244 (16)	0.0266 (17)	0.0039 (13)	0.0017 (13)	−0.0002 (13)
C10	0.0213 (15)	0.0271 (16)	0.0268 (17)	0.0005 (13)	0.0045 (13)	0.0034 (13)
C11	0.0261 (17)	0.0267 (17)	0.0302 (18)	0.0003 (13)	−0.0062 (14)	0.0018 (14)
C12	0.0312 (17)	0.0197 (15)	0.0245 (16)	0.0007 (12)	−0.0059 (14)	−0.0008 (13)
O1	0.0244 (12)	0.0489 (16)	0.0209 (13)	0.0015 (10)	0.0031 (9)	0.0000 (10)
Cl1	0.0227 (5)	0.0617 (7)	0.0423 (6)	0.0030 (4)	0.0066 (4)	0.0023 (4)

Geometric parameters (Å, º)

C1—C3^i	1.388 (4)	C6—C7	1.502 (5)
C1—C2	1.401 (5)	C7—C8	1.387 (5)
C1—H1	0.950	C7—C12	1.408 (4)
C2—C3	1.390 (5)	C8—C9	1.387 (5)
C2—C4	1.471 (4)	C8—H8	0.950
C3—C1^i	1.388 (4)	C9—C10	1.388 (5)
C3—H3	0.950	C9—H9	0.950
C4—C5	1.330 (5)	C10—C11	1.379 (5)
C4—H4	0.950	C10—Cl1	1.737 (3)
C5—C6	1.486 (4)	C11—C12	1.377 (5)
C5—H5	0.950	C11—H11	0.950
C6—O1	1.223 (4)	C12—H12	0.950
C3^i—C1—C2	121.3 (3)	C8—C7—C12	119.1 (3)
C3^i—C1—H1	119.4	C8—C7—C6	121.9 (3)
C2—C1—H1	119.4	C12—C7—C6	119.0 (3)
C3—C2—C1	118.3 (3)	C9—C8—C7	120.6 (3)
C3—C2—C4	123.1 (3)	C9—C8—H8	119.7
C1—C2—C4	118.5 (3)	C7—C8—H8	119.7
C1^i—C3—C2	120.4 (3)	C8—C9—C10	118.8 (3)
C1^i—C3—H3	119.8	C8—C9—H9	120.6
C2—C3—H3	119.8	C10—C9—H9	120.6
C5—C4—C2	126.3 (3)	C11—C10—C9	121.7 (3)
C5—C4—H4	116.9	C11—C10—Cl1	119.8 (3)
C2—C4—H4	116.9	C9—C10—Cl1	118.4 (3)
C4—C5—C6	120.6 (3)	C12—C11—C10	119.1 (3)
C4—C5—H5	119.7	C12—C11—H11	120.5
C6—C5—H5	119.7	C10—C11—H11	120.5
O1—C6—C5	121.9 (3)	C11—C12—C7	120.6 (3)
O1—C6—C7	121.1 (3)	C11—C12—H12	119.7
C5—C6—C7	116.9 (3)	C7—C12—H12	119.7
C3^i—C1—C2—C3	−1.6 (5)	C5—C6—C7—C12	158.7 (3)
C3^i—C1—C2—C4	175.0 (3)	C12—C7—C8—C9	1.6 (5)
C1—C2—C3—C1^i	1.6 (5)	C6—C7—C8—C9	−175.7 (3)
C4—C2—C3—C1^i	−174.8 (3)	C7—C8—C9—C10	−2.3 (5)
C3—C2—C4—C5	−4.1 (5)	C8—C9—C10—C11	1.2 (5)
C1—C2—C4—C5	179.5 (3)	C8—C9—C10—Cl1	−178.1 (2)
C2—C4—C5—C6	174.1 (3)	C9—C10—C11—C12	0.7 (5)
C4—C5—C6—O1	−19.3 (5)	Cl1—C10—C11—C12	180.0 (2)
C4—C5—C6—C7	160.9 (3)	C10—C11—C12—C7	−1.4 (5)
O1—C6—C7—C8	156.2 (3)	C8—C7—C12—C11	0.3 (5)
C5—C6—C7—C8	−24.0 (4)	C6—C7—C12—C11	177.6 (3)
O1—C6—C7—C12	−21.1 (4)

Symmetry code: (i) −x, −y+1, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1···Cg1^ii	0.95	2.70	3.400 (3)	131
C9—H9···Cg2^iii	0.95	2.77	3.422 (4)	127
C12—H12···Cg2^iv	0.95	2.83	3.457 (3)	124

Symmetry codes: (ii) −x, y−1/2, −z+1/2; (iii) x, −y+1/2, z−1/2; (iv) x, −y+3/2, z+1/2.