(2E)-3-(3,5-Dichloro-4-meth­oxy-2,6-di­methyl­phen­yl)-1-(2,4-dichloro­phen­yl)­prop-2-en-1-one

In the title mol­ecule, C₁₈H₁₄Cl₄O₂, the angle between the mean planes of the 3,5-dichloro-4-meth­oxy-2,6-dimethyl­phenyl and 2,4-dichloro­phenyl groups is 47.6 (2)°. The 4-meth­oxy group, with a torsion angle of 91.9 (9)°, is twisted away from the plane of the 3,5-dichloro-2,6-dimethyl­phenyl ring in an anti­clinal conformation. The ketone O atom of the prop-2-en-1-one group is twisted in a synclinal conformation with the 2,4-dichloro­phenyl group [torsion angle = 45.5 (11)°]. The crystal packing is stabilized by inter­molecular C—H...O hydrogen bonding between the ketone O atom from the prop-2-en-1-one group and an H atom from a nearby 2,4-dichloro­phenyl group, which link the mol­ecules into chains along the a axis. The 3,5-dichloro-4-meth­oxy-2,6-dimethyl­phenyl and 2,4-dichloro­phenyl groups are aligned obliquely parallel to the ac face, with the benzene rings stacked obliquely along the b axis for both groups.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.011 Å
• R factor = 0.081
• wR factor = 0.239
• Data-to-parameter ratio = 18.7

checkCIF/PLATON results

No syntax errors found



Alert level B
ABSTM02_ALERT_3_B  The ratio of expected to reported Tmax/Tmin(RR') is < 0.75
            Tmin and Tmax reported:      0.502     1.000
            Tmin(prime) and Tmax expected:      0.777     0.858
            RR(prime) =      0.554
            Please check that your absorption correction is appropriate.
PLAT061_ALERT_3_B Tmax/Tmin Range Test RR' too Large .............       0.55
PLAT340_ALERT_3_B Low Bond Precision on C-C Bonds (x 1000) Ang ...         11

Alert level C
PLAT034_ALERT_1_C No Flack Parameter Given. Z .GT. Si, NonCentro .          ?
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.86

Alert level G
ABSTM02_ALERT_3_G  When printed, the submitted absorption T values will be
            replaced by the scaled T values. Since the ratio of scaled T's
            is identical to the ratio of reported T values, the scaling
            does not imply a change to the absorption corrections used in
            the study.
            Ratio of Tmax expected/reported      0.858
            Tmax scaled      0.858 Tmin scaled      0.431
REFLT03_ALERT_4_G  WARNING: Large fraction of Friedel related reflns may
                     be needed to determine absolute structure
           From the CIF: _diffrn_reflns_theta_max           32.51
           From the CIF: _reflns_number_total               4142
           Count of symmetry unique reflns         3271
           Completeness (_total/calc)            126.63%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured       871
           Fraction of Friedel pairs measured     0.266
           Are heavy atom types Z>Si present        yes
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          2

   0 ALERT level A = In general: serious problem
   3 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   3 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
   5 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Chalcone is an unique template molecule that is associated with several biological activities. Chalcones can be easily obtained from the aldol condensation of aromatic aldehydes and aromatic ketones. This class of compounds presents interesting biological properties such as cytotoxicity (Pandey et al. 2005), antiherpes activity and antitumour activity and may be useful for the chemotherapy of leishmaniasis among others (Lawrence et al. 2001). Among several organic compounds reported to have NLO properties, chalcone derivatives are a recognized material because of their excellent blue light transmittance and good crystallization ability (Goto et al. 1991; Indira et al. 2002; Sarojini et al. 2006). Structures of a few dichloro substituted chalcones viz., (2E)-1-(2,4-dichlorophenyl)-3-(quinolin-8-yl)prop-2-en-1-one (Sarojini et al. 2007), (2E)-1-(2,4-dichlorophenyl)-3-(4,5-dimethoxy-2-nitrophenyl) prop-2-en-1-one (Yathirajan, Mayekar, Narayana et al. 2007c), (2E)-1-(2,4-dichlorophenyl)-3-(6-methoxy-2-naphthyl)prop-2-en-1-one (Yathirajan, Mayekar, Narayana et al. 2007b), (2E)-1-(2,4-dichlorophenyl)-3-(2-hydroxy-3-methoxyphenyl) prop-2-en-1-one (Yathirajan, Mayekar, Narayana et al. 2007a), (2E)-1-(2,4-dichlorophenyl)-3-(4-nitrophenyl)prop-2-en-1-one (Yathirajan, Mayekar, Sarojini et al. 2007a) and (2E)-1-(2,4-dichlorophenyl)-3-(2-hydroxyphenyl)prop-2-en-1-one (Yathirajan, Mayekar, Sarojini et al. 2007b) have been published. In continuation of our work on chalcones, a new chalcone C₁₈H₁₄Cl₄O₂ was synthesized and its crystal structure is reported.

The angle between the mean planes of the 3,5-dichloro-4-methoxy-2,6-dimethylphenyl and 2,4-dichlorophenyl groups is 47.6 (2)° (Fig. 1). The 4-methoxy group, with a C15–O2–C14–C13 torsion angle of 91.9 (9)°, is twisted away from the plane of the 3,5-dichloro-2,6-dimethylphenyl ring in an anti-clinal conformation. The ketone oxygen of the prop-2-en-1-one group is twisted in a syn-clinal conformation with the 2,4-dichlorophenyl group [C6–C1–C7–O1 torsion angle = 45.5 (11)°]. Crystal packing is stabilized by intermolecular C—H···O hydrogen bonding between the ketone oxygen from the prop-2-en-1-one group and a hydrogen atom from a nearby 2,4-dichlorophenyl group [C3–H3A···O1] which link the molecules into chains along the a axis of the unit cell (Fig. 2). Both of the 3,5-dichloro-4-methoxy-2,6-dimethylphenyl and 2,4-dichlorophenyl groups are aligned obliquely parallel to the ac face with the phenyl rings stacked obliquely along the b axis for both groups (Fig. 3).

Related literature

For related structures, see: Sarojini et al. (2007); Yathirajan, Mayekar, Narayana et al. (2007a,b,c; Yathirajan, Mayekar, Sarojini et al. 2007a,b). For related literature, see: Goto et al. (1991); Indira et al. (2002); Lawrence et al. (2001); Pandey et al. (2005); Sarojini et al. (2006).

S2. Experimental

3,5-Dichloro-4-methoxy-2,6-dimethylbenzaldehyde (2.33 g, 0.01 mol) in ethanol (30 ml) was mixed with 1-(2,4-dichlorophenyl)ethanone (1.89 g, 0.01 mol) in ethanol (20 ml) and the mixture was treated with 8 ml of 10% KOH solution (Fig. 4). The reaction mixture was then kept for constant stirring. The solid precipitate obtained was filtered, washed with ethanol and dried. The crystal growth was carried out from a 1:1 mixture of acetone and toluene by the slow evaporation technique (m.p.: 401–403 K). Analysis found: C 53.41, H 3.43%; C₁₈H₁₄Cl₄O₂ requires: C 53.50, H 3.49%.

S3. Refinement

All H atoms were placed in their calculated places and refined using a riding model with C—H = 0.93 to 0.96 Å, and with U_iso(H) = 1.19–1.50U_eq(C).

Computing details

Data collection: CrysAlis PRO (Oxford Diffraction, 2007); cell refinement: CrysAlis PRO (Oxford Diffraction, 2007); data reduction: CrysAlis PRO (Oxford Diffraction, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2000); software used to prepare material for publication: SHELXTL (Bruker, 2000).

Figures

	Fig. 1. Molecular structure of the title compound, showing atom labeling and 50% probability displacement ellipsoids.
	Fig. 2. Packing diagram of the title compound, viewed down the b axis.
	Fig. 3. Packing diagram of the title compound, viewed down the a axis.
	Fig. 4. Synthetic scheme for C18H14Cl4O2.

(2E)-3-(3,5-Dichloro-4-methoxy-2,6-dimethylphenyl)-1-(2,4-dichlorophenyl)prop- 2-en-1-one

Crystal data

C18H14Cl4O2	F(000) = 412
Mr = 404.09	Dx = 1.492 Mg m^−3
Monoclinic, Pc	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P -2yc	Cell parameters from 3151 reflections
a = 7.8036 (4) Å	θ = 4.7–32.4°
b = 4.3526 (2) Å	µ = 0.67 mm^−1
c = 26.6839 (11) Å	T = 296 K
β = 97.020 (4)°	Chunk, colourless
V = 899.55 (7) Å^3	0.37 × 0.31 × 0.23 mm
Z = 2

Data collection

Oxford Diffraction Gemini R CCD diffractometer	4142 independent reflections
Radiation source: fine-focus sealed tube	2501 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.045
Detector resolution: 10.5081 pixels mm^-1	θmax = 32.5°, θmin = 4.8°
φ and ω scans	h = −10→11
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2007)	k = −6→6
Tmin = 0.502, Tmax = 1.000	l = −39→39
8039 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.081	H-atom parameters constrained
wR(F^2) = 0.239	w = 1/[σ^2(Fo^2) + (0.128P)^2 + 0.8404P] where P = (Fo^2 + 2Fc^2)/3
S = 1.03	(Δ/σ)max = 0.001
4142 reflections	Δρmax = 0.80 e Å^−3
221 parameters	Δρmin = −0.55 e Å^−3
2 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.090 (11)

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
Cl1	−0.1343 (3)	−0.2032 (6)	0.41662 (8)	0.0672 (6)
Cl2	−0.2962 (4)	0.4321 (8)	0.57611 (11)	0.0929 (9)
Cl3	0.63088 (19)	0.5365 (4)	0.21399 (6)	0.0454 (4)
Cl4	0.0016 (2)	−0.0404 (5)	0.17461 (7)	0.0546 (5)
O1	0.3767 (9)	−0.067 (2)	0.4676 (2)	0.083 (2)
O2	0.3069 (7)	0.3112 (13)	0.15441 (19)	0.0585 (13)
C1	0.1023 (9)	0.1380 (17)	0.4771 (2)	0.0471 (15)
C2	−0.0731 (9)	0.0404 (17)	0.4674 (3)	0.0488 (16)
C3	−0.1907 (10)	0.120 (2)	0.4978 (3)	0.0542 (17)
H3A	−0.3032	0.0465	0.4920	0.065*
C4	−0.1405 (10)	0.317 (2)	0.5384 (3)	0.0590 (19)
C5	0.0273 (13)	0.405 (2)	0.5501 (3)	0.067 (2)
H5A	0.0606	0.5270	0.5782	0.080*
C6	0.1454 (11)	0.309 (2)	0.5198 (3)	0.061 (2)
H6A	0.2606	0.3620	0.5285	0.073*
C7	0.2420 (9)	0.0391 (17)	0.4465 (2)	0.0479 (15)
C8	0.2188 (10)	0.099 (2)	0.3920 (3)	0.0564 (18)
H8A	0.1153	0.1870	0.3780	0.068*
C9	0.3307 (11)	0.038 (2)	0.3625 (3)	0.0554 (18)
H9A	0.4312	−0.0550	0.3777	0.067*
C10	0.3237 (9)	0.0957 (17)	0.3066 (3)	0.0478 (15)
C11	0.4588 (10)	0.2643 (17)	0.2898 (3)	0.0515 (16)
C12	0.6065 (11)	0.383 (2)	0.3266 (3)	0.062 (2)
H12A	0.7138	0.3094	0.3170	0.092*
H12B	0.5936	0.3108	0.3599	0.092*
H12C	0.6060	0.6033	0.3263	0.092*
C13	0.4546 (10)	0.3347 (19)	0.2390 (3)	0.0525 (16)
C14	0.3116 (10)	0.2325 (17)	0.2042 (2)	0.0485 (15)
C15	0.3859 (13)	0.088 (2)	0.1242 (3)	0.062 (2)
H15A	0.3837	0.1642	0.0904	0.093*
H15B	0.3230	−0.1015	0.1238	0.093*
H15C	0.5032	0.0542	0.1386	0.093*
C16	0.1818 (9)	0.0693 (16)	0.2219 (3)	0.0462 (15)
C17	0.1824 (10)	−0.0016 (18)	0.2732 (3)	0.0501 (16)
C18	0.0396 (12)	−0.197 (2)	0.2895 (3)	0.062 (2)
H18A	0.0630	−0.2386	0.3250	0.093*
H18B	0.0332	−0.3872	0.2711	0.093*
H18C	−0.0682	−0.0899	0.2827	0.093*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0663 (12)	0.0760 (14)	0.0580 (10)	−0.0069 (10)	0.0026 (8)	−0.0058 (10)
Cl2	0.0866 (17)	0.123 (2)	0.0776 (14)	0.0037 (16)	0.0454 (13)	−0.0149 (15)
Cl3	0.0402 (8)	0.0484 (8)	0.0485 (8)	−0.0094 (7)	0.0093 (6)	0.0048 (8)
Cl4	0.0430 (9)	0.0764 (13)	0.0439 (8)	−0.0096 (9)	0.0032 (7)	−0.0044 (9)
O1	0.060 (4)	0.135 (6)	0.055 (3)	0.013 (4)	0.012 (3)	0.013 (4)
O2	0.076 (4)	0.053 (3)	0.048 (2)	0.001 (3)	0.013 (2)	0.012 (2)
C1	0.047 (4)	0.057 (4)	0.038 (3)	0.002 (3)	0.010 (3)	0.005 (3)
C2	0.037 (3)	0.063 (4)	0.047 (3)	0.016 (3)	0.003 (3)	0.006 (3)
C3	0.051 (4)	0.066 (4)	0.047 (3)	−0.004 (3)	0.012 (3)	0.017 (3)
C4	0.054 (4)	0.076 (5)	0.051 (4)	0.006 (4)	0.020 (3)	0.008 (4)
C5	0.073 (6)	0.084 (6)	0.045 (4)	−0.004 (5)	0.008 (4)	−0.011 (4)
C6	0.054 (5)	0.080 (6)	0.047 (3)	−0.007 (4)	0.004 (3)	0.002 (4)
C7	0.046 (4)	0.059 (4)	0.038 (3)	0.007 (3)	0.003 (3)	0.007 (3)
C8	0.048 (4)	0.083 (5)	0.038 (3)	0.004 (4)	0.006 (3)	0.003 (3)
C9	0.051 (4)	0.071 (5)	0.043 (3)	−0.002 (3)	0.001 (3)	−0.006 (3)
C10	0.041 (3)	0.057 (4)	0.047 (3)	0.007 (3)	0.016 (3)	0.000 (3)
C11	0.066 (4)	0.044 (4)	0.046 (3)	0.002 (3)	0.009 (3)	−0.011 (3)
C12	0.046 (4)	0.079 (6)	0.058 (4)	0.001 (4)	0.000 (3)	−0.011 (4)
C13	0.052 (4)	0.058 (4)	0.049 (3)	−0.003 (3)	0.014 (3)	−0.002 (3)
C14	0.060 (4)	0.048 (4)	0.038 (3)	0.011 (3)	0.006 (3)	0.007 (3)
C15	0.082 (6)	0.062 (5)	0.045 (4)	−0.002 (4)	0.015 (4)	0.000 (3)
C16	0.042 (3)	0.052 (4)	0.045 (3)	0.005 (3)	0.005 (3)	−0.003 (3)
C17	0.046 (4)	0.062 (5)	0.045 (3)	0.003 (3)	0.017 (3)	−0.003 (3)
C18	0.065 (5)	0.066 (5)	0.059 (4)	−0.005 (4)	0.025 (4)	−0.005 (4)

Geometric parameters (Å, º)

Cl1—C2	1.741 (8)	C9—C10	1.509 (10)
Cl2—C4	1.743 (8)	C9—H9A	0.9300
Cl3—C13	1.825 (8)	C10—C17	1.396 (11)
Cl4—C16	1.834 (7)	C10—C11	1.402 (11)
O1—C7	1.221 (9)	C11—C13	1.386 (10)
O2—C14	1.369 (7)	C11—C12	1.511 (11)
O2—C15	1.445 (10)	C12—H12A	0.9600
C1—C6	1.367 (11)	C12—H12B	0.9600
C1—C2	1.426 (11)	C12—H12C	0.9600
C1—C7	1.503 (10)	C13—C14	1.432 (11)
C2—C3	1.342 (10)	C14—C16	1.367 (11)
C3—C4	1.400 (12)	C15—H15A	0.9600
C3—H3A	0.9300	C15—H15B	0.9600
C4—C5	1.363 (13)	C15—H15C	0.9600
C5—C6	1.364 (12)	C16—C17	1.402 (10)
C5—H5A	0.9300	C17—C18	1.508 (11)
C6—H6A	0.9300	C18—H18A	0.9600
C7—C8	1.468 (9)	C18—H18B	0.9600
C8—C9	1.272 (11)	C18—H18C	0.9600
C8—H8A	0.9300
C14—O2—C15	114.2 (6)	C13—C11—C12	119.1 (7)
C6—C1—C2	116.5 (7)	C10—C11—C12	120.9 (7)
C6—C1—C7	119.2 (7)	C11—C12—H12A	109.5
C2—C1—C7	124.0 (6)	C11—C12—H12B	109.5
C3—C2—C1	121.6 (7)	H12A—C12—H12B	109.5
C3—C2—Cl1	119.0 (6)	C11—C12—H12C	109.5
C1—C2—Cl1	119.3 (5)	H12A—C12—H12C	109.5
C2—C3—C4	118.6 (7)	H12B—C12—H12C	109.5
C2—C3—H3A	120.7	C11—C13—C14	119.2 (7)
C4—C3—H3A	120.7	C11—C13—Cl3	122.3 (6)
C5—C4—C3	121.2 (7)	C14—C13—Cl3	118.4 (5)
C5—C4—Cl2	120.4 (7)	C16—C14—O2	122.2 (7)
C3—C4—Cl2	118.3 (6)	C16—C14—C13	119.3 (6)
C4—C5—C6	118.6 (8)	O2—C14—C13	118.5 (7)
C4—C5—H5A	120.7	O2—C15—H15A	109.5
C6—C5—H5A	120.7	O2—C15—H15B	109.5
C5—C6—C1	123.1 (8)	H15A—C15—H15B	109.5
C5—C6—H6A	118.5	O2—C15—H15C	109.5
C1—C6—H6A	118.5	H15A—C15—H15C	109.5
O1—C7—C8	121.2 (7)	H15B—C15—H15C	109.5
O1—C7—C1	120.0 (6)	C14—C16—C17	122.5 (6)
C8—C7—C1	118.6 (6)	C14—C16—Cl4	115.8 (5)
C9—C8—C7	124.4 (7)	C17—C16—Cl4	121.7 (6)
C9—C8—H8A	117.8	C10—C17—C16	117.7 (6)
C7—C8—H8A	117.8	C10—C17—C18	122.7 (6)
C8—C9—C10	129.2 (7)	C16—C17—C18	119.4 (7)
C8—C9—H9A	115.4	C17—C18—H18A	109.5
C10—C9—H9A	115.4	C17—C18—H18B	109.5
C17—C10—C11	121.4 (6)	H18A—C18—H18B	109.5
C17—C10—C9	120.8 (6)	C17—C18—H18C	109.5
C11—C10—C9	117.7 (7)	H18A—C18—H18C	109.5
C13—C11—C10	119.9 (7)	H18B—C18—H18C	109.5
C6—C1—C2—C3	2.0 (11)	C17—C10—C11—C12	176.8 (7)
C7—C1—C2—C3	175.8 (7)	C9—C10—C11—C12	0.2 (11)
C6—C1—C2—Cl1	−174.9 (6)	C10—C11—C13—C14	−0.2 (11)
C7—C1—C2—Cl1	−1.1 (9)	C12—C11—C13—C14	−177.7 (7)
C1—C2—C3—C4	3.3 (11)	C10—C11—C13—Cl3	−176.9 (6)
Cl1—C2—C3—C4	−179.8 (6)	C12—C11—C13—Cl3	5.6 (11)
C2—C3—C4—C5	−6.0 (12)	C15—O2—C14—C16	−90.7 (9)
C2—C3—C4—Cl2	177.4 (6)	C15—O2—C14—C13	91.6 (9)
C3—C4—C5—C6	3.2 (13)	C11—C13—C14—C16	0.4 (11)
Cl2—C4—C5—C6	179.8 (7)	Cl3—C13—C14—C16	177.2 (6)
C4—C5—C6—C1	2.4 (14)	C11—C13—C14—O2	178.2 (7)
C2—C1—C6—C5	−5.0 (12)	Cl3—C13—C14—O2	−5.0 (10)
C7—C1—C6—C5	−179.1 (8)	O2—C14—C16—C17	−177.4 (7)
C6—C1—C7—O1	45.5 (11)	C13—C14—C16—C17	0.3 (11)
C2—C1—C7—O1	−128.2 (9)	O2—C14—C16—Cl4	0.5 (9)
C6—C1—C7—C8	−129.2 (8)	C13—C14—C16—Cl4	178.2 (6)
C2—C1—C7—C8	57.1 (10)	C11—C10—C17—C16	1.3 (11)
O1—C7—C8—C9	2.3 (14)	C9—C10—C17—C16	177.8 (7)
C1—C7—C8—C9	176.9 (8)	C11—C10—C17—C18	176.7 (7)
C7—C8—C9—C10	−178.3 (8)	C9—C10—C17—C18	−6.8 (12)
C8—C9—C10—C17	−51.5 (13)	C14—C16—C17—C10	−1.2 (11)
C8—C9—C10—C11	125.1 (10)	Cl4—C16—C17—C10	−178.9 (5)
C17—C10—C11—C13	−0.7 (11)	C14—C16—C17—C18	−176.7 (7)
C9—C10—C11—C13	−177.2 (7)	Cl4—C16—C17—C18	5.5 (10)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3A···O1^i	0.93	2.55	3.471 (11)	170

Symmetry code: (i) x−1, y, z.