1,4-Bis(4-chloro­phen­yl)butane-1,4-dione

The mol­ecule of title compound, C₁₆H₁₂Cl₂O₂, is centrosymmetric. Thus, the asymmetric unit comprises two half-mol­ecules. The two benzene rings are coplanar in each independent molecule (dihedral angles = 0°). The crystal packing exhibits inter­molecular C—H...O hydrogen bonds and C—H...π inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.042
• wR factor = 0.117
• Data-to-parameter ratio = 15.4

checkCIF/PLATON results

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Alert level C
            Value of measurement temperature given =   298.000
            Value of melting point given =     0.000
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 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
   0 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

1,4-Diketones are very useful intermediates for the synthesis of substituted furans, pyrroles and thiophenes via Paal-Knorr cyclization reaction (Rao et al., 2004; Stauffer et al., 2000; Shridhar et al., 1982). A variety of methods have been reported for the preparation of these 1,4-dicarbonyl compounds (Stetter et al., 1976; Yamamoto et al., 2003; Yuguchi et al., 2004).

The molecule is centrosymmetric. There are two halves of the molecules in the asymmetric unit (Fig. 1). The two phenyl rings are co-planar in both molecules. Intermolecular C—H···O hydrogen bonds and C—H···π interactions stabilize the crystal packing (Table 1).

Related literature

For applications of the title compound, see: Rao et al. (2004); Stauffer & Neier (2000); Shridhar et al. (1982). For the preparation of the title compound, see: Stetter (1976); Nimgirawath et al. (1976); Yamamoto et al. (2003); Yuguchi et al. (2004).

S2. Experimental

The title compound was synthesized as previously described by Nimgirawath et al. (1976). Colourless crystals suitable for X-ray data collection were obtained by slow evaporation of a 1:2 (v/v) ratio CH₂Cl₂:CH₃OH solution at 293 K.

S3. Refinement

All H atoms were refine independently; C—H (methyl H) = 0.96 Å, C—H (methine H) = 0.93Å and 0.93 Å for thiophene H. The constraint U_iso(H) = 1.2U_eq(C) or 1.5U_eq (methyl C) was applied.

Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SMART (Bruker, 2001); data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

Fig. 1. View of the title molecule showing the atom-labelling scheme. The displacement ellipsoids are drawn at the 30% probability level. H atoms are represented by spheres of arbitrary radius.

1,4-Bis(4-chlorophenyl)butane-1,4-dione

Crystal data

C16H12Cl2O2	F(000) = 632
Mr = 307.16	Dx = 1.441 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3417 reflections
a = 10.3663 (2) Å	θ = 2.6–23.1°
b = 5.2532 (1) Å	µ = 0.46 mm^−1
c = 26.1125 (6) Å	T = 298 K
β = 95.272 (2)°	Block, colourless
V = 1415.97 (5) Å^3	0.20 × 0.10 × 0.10 mm
Z = 4

Data collection

Bruker SMART CCD area-detector diffractometer	2789 independent reflections
Radiation source: fine-focus sealed tube	1836 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.058
ϕ and ω scans	θmax = 26.0°, θmin = 1.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 1997)	h = −12→12
Tmin = 0.914, Tmax = 0.956	k = −6→6
14170 measured reflections	l = −31→32

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)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.117	H-atom parameters constrained
S = 0.97	w = 1/[σ^2(Fo^2) + (0.0637P)^2] where P = (Fo^2 + 2Fc^2)/3
2789 reflections	(Δ/σ)max = 0.001
181 parameters	Δρmax = 0.21 e Å^−3
0 restraints	Δρmin = −0.23 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	0.3102 (2)	0.4151 (4)	0.32315 (8)	0.0609 (5)
C2	0.3437 (2)	0.2160 (4)	0.35628 (8)	0.0658 (6)
H2	0.4069	0.0995	0.3488	0.079*
C3	0.2824 (2)	0.1933 (4)	0.40024 (8)	0.0612 (6)
H3	0.3041	0.0584	0.4225	0.073*
C4	0.18851 (19)	0.3661 (3)	0.41264 (8)	0.0524 (5)
C5	0.1579 (2)	0.5660 (4)	0.37840 (8)	0.0590 (5)
H5	0.0960	0.6851	0.3859	0.071*
C6	0.2175 (2)	0.5899 (4)	0.33398 (8)	0.0627 (6)
H6	0.1955	0.7228	0.3113	0.075*
C7	0.1272 (2)	0.3362 (4)	0.46133 (8)	0.0559 (5)
C8	0.0298 (2)	0.5308 (4)	0.47540 (7)	0.0576 (5)
H8A	−0.0386	0.5432	0.4476	0.069*
H8B	0.0719	0.6955	0.4790	0.069*
C9	0.1559 (2)	0.7318 (4)	0.15908 (8)	0.0593 (5)
C10	0.1743 (2)	0.6200 (4)	0.11264 (8)	0.0623 (6)
H10	0.1275	0.4755	0.1019	0.075*
C11	0.2621 (2)	0.7227 (4)	0.08217 (8)	0.0575 (5)
H11	0.2745	0.6459	0.0509	0.069*
C12	0.33228 (18)	0.9383 (3)	0.09714 (7)	0.0508 (5)
C13	0.3118 (2)	1.0476 (4)	0.14417 (8)	0.0628 (6)
H13	0.3581	1.1926	0.1549	0.075*
C14	0.2249 (2)	0.9467 (4)	0.17514 (8)	0.0674 (6)
H14	0.2127	1.0220	0.2066	0.081*
C15	0.42674 (19)	1.0574 (4)	0.06459 (7)	0.0537 (5)
C16	0.45259 (19)	0.9285 (4)	0.01517 (8)	0.0558 (5)
H16A	0.3713	0.9095	−0.0061	0.067*
H16B	0.4865	0.7594	0.0229	0.067*
Cl1	0.04740 (6)	0.59996 (12)	0.19828 (2)	0.0828 (2)
Cl2	0.38806 (6)	0.44975 (15)	0.26764 (2)	0.0908 (3)
O1	0.15594 (16)	0.1582 (3)	0.48988 (6)	0.0830 (5)
O2	0.48192 (15)	1.2536 (3)	0.07810 (6)	0.0746 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0561 (13)	0.0641 (12)	0.0619 (13)	−0.0073 (11)	0.0012 (10)	−0.0094 (10)
C2	0.0571 (13)	0.0598 (13)	0.0800 (15)	0.0045 (11)	0.0034 (12)	−0.0096 (12)
C3	0.0596 (14)	0.0472 (11)	0.0746 (14)	0.0029 (10)	−0.0055 (11)	0.0030 (10)
C4	0.0524 (12)	0.0432 (10)	0.0596 (12)	−0.0020 (9)	−0.0061 (10)	0.0006 (9)
C5	0.0639 (14)	0.0499 (11)	0.0632 (13)	0.0086 (10)	0.0063 (10)	0.0010 (10)
C6	0.0705 (15)	0.0559 (12)	0.0609 (13)	0.0026 (11)	0.0023 (11)	0.0044 (10)
C7	0.0566 (13)	0.0454 (11)	0.0637 (13)	−0.0034 (9)	−0.0049 (10)	0.0052 (9)
C8	0.0648 (14)	0.0473 (11)	0.0600 (12)	−0.0027 (10)	0.0017 (10)	0.0039 (9)
C9	0.0569 (13)	0.0607 (12)	0.0600 (13)	0.0043 (10)	0.0036 (10)	0.0077 (10)
C10	0.0634 (14)	0.0543 (12)	0.0682 (14)	−0.0080 (10)	0.0007 (11)	−0.0027 (10)
C11	0.0614 (13)	0.0531 (11)	0.0575 (12)	−0.0005 (10)	0.0036 (10)	−0.0074 (9)
C12	0.0530 (12)	0.0478 (10)	0.0504 (11)	0.0042 (9)	−0.0017 (9)	−0.0011 (9)
C13	0.0733 (15)	0.0528 (12)	0.0609 (13)	−0.0079 (11)	−0.0011 (11)	−0.0067 (10)
C14	0.0807 (16)	0.0673 (14)	0.0543 (12)	−0.0008 (12)	0.0064 (11)	−0.0065 (11)
C15	0.0502 (12)	0.0520 (11)	0.0577 (12)	0.0030 (10)	−0.0020 (9)	−0.0021 (9)
C16	0.0504 (12)	0.0559 (11)	0.0599 (12)	0.0011 (9)	−0.0012 (9)	−0.0014 (9)
Cl1	0.0788 (5)	0.0941 (5)	0.0772 (4)	−0.0099 (3)	0.0169 (3)	0.0112 (3)
Cl2	0.0818 (5)	0.1167 (6)	0.0764 (4)	0.0026 (4)	0.0215 (3)	−0.0058 (4)
O1	0.0957 (13)	0.0697 (10)	0.0855 (11)	0.0224 (9)	0.0175 (9)	0.0298 (9)
O2	0.0803 (11)	0.0631 (9)	0.0819 (11)	−0.0212 (8)	0.0150 (8)	−0.0150 (8)

Geometric parameters (Å, º)

C1—C6	1.377 (3)	C9—C14	1.381 (3)
C1—C2	1.381 (3)	C9—Cl1	1.733 (2)
C1—Cl2	1.732 (2)	C10—C11	1.373 (3)
C2—C3	1.368 (3)	C10—H10	0.9300
C2—H2	0.9300	C11—C12	1.383 (3)
C3—C4	1.391 (3)	C11—H11	0.9300
C3—H3	0.9300	C12—C13	1.390 (3)
C4—C5	1.397 (3)	C12—C15	1.492 (3)
C4—C7	1.481 (3)	C13—C14	1.371 (3)
C5—C6	1.369 (3)	C13—H13	0.9300
C5—H5	0.9300	C14—H14	0.9300
C6—H6	0.9300	C15—O2	1.215 (2)
C7—O1	1.216 (2)	C15—C16	1.503 (3)
C7—C8	1.506 (3)	C16—C16^ii	1.517 (4)
C8—C8^i	1.511 (4)	C16—H16A	0.9700
C8—H8A	0.9700	C16—H16B	0.9700
C8—H8B	0.9700	Cl1—Cl2	3.8985 (9)
C9—C10	1.376 (3)
C6—C1—C2	121.1 (2)	C10—C9—Cl1	120.01 (17)
C6—C1—Cl2	119.31 (17)	C14—C9—Cl1	119.58 (16)
C2—C1—Cl2	119.60 (18)	C11—C10—C9	119.75 (19)
C3—C2—C1	118.8 (2)	C11—C10—H10	120.1
C3—C2—H2	120.6	C9—C10—H10	120.1
C1—C2—H2	120.6	C10—C11—C12	121.17 (19)
C2—C3—C4	121.84 (19)	C10—C11—H11	119.4
C2—C3—H3	119.1	C12—C11—H11	119.4
C4—C3—H3	119.1	C11—C12—C13	117.95 (19)
C3—C4—C5	117.68 (19)	C11—C12—C15	122.57 (17)
C3—C4—C7	119.70 (18)	C13—C12—C15	119.47 (17)
C5—C4—C7	122.62 (19)	C14—C13—C12	121.59 (19)
C6—C5—C4	121.17 (19)	C14—C13—H13	119.2
C6—C5—H5	119.4	C12—C13—H13	119.2
C4—C5—H5	119.4	C13—C14—C9	119.2 (2)
C5—C6—C1	119.39 (19)	C13—C14—H14	120.4
C5—C6—H6	120.3	C9—C14—H14	120.4
C1—C6—H6	120.3	O2—C15—C12	120.42 (18)
O1—C7—C4	120.50 (19)	O2—C15—C16	120.99 (19)
O1—C7—C8	120.30 (19)	C12—C15—C16	118.58 (17)
C4—C7—C8	119.20 (16)	C15—C16—C16^ii	113.6 (2)
C7—C8—C8^i	113.5 (2)	C15—C16—H16A	108.8
C7—C8—H8A	108.9	C16^ii—C16—H16A	108.8
C8^i—C8—H8A	108.9	C15—C16—H16B	108.8
C7—C8—H8B	108.9	C16^ii—C16—H16B	108.8
C8^i—C8—H8B	108.9	H16A—C16—H16B	107.7
H8A—C8—H8B	107.7	C9—Cl1—Cl2	75.29 (7)
C10—C9—C14	120.4 (2)	C1—Cl2—Cl1	86.46 (7)
C6—C1—C2—C3	0.5 (3)	C10—C11—C12—C13	0.3 (3)
Cl2—C1—C2—C3	179.23 (15)	C10—C11—C12—C15	−178.93 (18)
C1—C2—C3—C4	−0.6 (3)	C11—C12—C13—C14	0.0 (3)
C2—C3—C4—C5	0.2 (3)	C15—C12—C13—C14	179.26 (19)
C2—C3—C4—C7	−178.57 (18)	C12—C13—C14—C9	−0.2 (3)
C3—C4—C5—C6	0.5 (3)	C10—C9—C14—C13	0.2 (3)
C7—C4—C5—C6	179.23 (18)	Cl1—C9—C14—C13	179.13 (16)
C4—C5—C6—C1	−0.7 (3)	C11—C12—C15—O2	176.53 (19)
C2—C1—C6—C5	0.2 (3)	C13—C12—C15—O2	−2.7 (3)
Cl2—C1—C6—C5	−178.55 (15)	C11—C12—C15—C16	−3.9 (3)
C3—C4—C7—O1	−1.9 (3)	C13—C12—C15—C16	176.85 (17)
C5—C4—C7—O1	179.45 (18)	O2—C15—C16—C16^ii	−2.1 (3)
C3—C4—C7—C8	177.44 (18)	C12—C15—C16—C16^ii	178.39 (19)
C5—C4—C7—C8	−1.2 (3)	C10—C9—Cl1—Cl2	107.86 (17)
O1—C7—C8—C8^i	−3.6 (3)	C14—C9—Cl1—Cl2	−71.11 (16)
C4—C7—C8—C8^i	177.0 (2)	C6—C1—Cl2—Cl1	−43.73 (16)
C14—C9—C10—C11	0.1 (3)	C2—C1—Cl2—Cl1	137.48 (16)
Cl1—C9—C10—C11	−178.83 (15)	C9—Cl1—Cl2—C1	158.48 (10)
C9—C10—C11—C12	−0.4 (3)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C8—H8B···O1^iii	0.97	2.59	3.553 (3)	173
C11—H11···O1^iv	0.93	2.50	3.246 (2)	138
C8—H8A···Cg1^v	0.97	2.98	3.876 (2)	154

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