3,4-Bis(4-bromo­phen­yl)-2,5-diphenyl­cyclo­penta-2,4-dienone

The title compound, C₂₉H₁₈Br₂O, crystallizes as black–violet plates. The mol­ecule displays a paddle-wheel conformation and the crystal packing is stabilized by C—H...π (C—H...π distances in the range 2.7–2.9 Å) and C—H...Br contacts.

Key indicators

• Single-crystal X-ray study
• T = 93 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.019
• wR factor = 0.047
• Data-to-parameter ratio = 13.8

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.93
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT480_ALERT_4_C Long H...A H-Bond Reported H22    ..  BR2     ..       2.97 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H15    ..  BR1     ..       3.03 Ang.

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      0.929
            Tmax scaled      0.524 Tmin scaled      0.496

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

   0 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
   1 ALERT type 3 Indicator that the structure quality may be low
   4 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

---

S1. Comment

The molecular geometry is best described by a paddle-wheel fashion, due to steric hindrance of the neighbouring aryl rings. The crystal packing is dominated by intramolecular C—H···π interactions. These intermolecular contacts, where π is an aromatic-ring centroid, with H···π distances ranging from 2.67 to 2.90 Å give rise to the formation of molecular chains extended along the a and b axis. Furthermore, unusual C—H···Br contacts forming a three-dimensional network can be observed (Figure 2).

Related literature

The paddle-wheel conformation is also a typical feature of the parent substance tetraphenylcyclone (Barnes et al., 1991; Alvarez-Toledano et al., 1997) and the related compound phencyclone (Ruffani et al., 2006), both involving C—H···π contacts in the crystal packing, similar to the title compound. For related literature, see: Dilthey et al. (1935).

S2. Experimental

The title compound was synthesized according to the procedure described by Dilthey et al. (1935) from 1,2-bis(4-bromophenyl) ethane-1,2-dione, dibenzyl ketone and finely powdered potassium hydroxide in ethanol. Recrystallization from ethyl acetate yielded 72% dark-violet crystals.

S3. Refinement

The H atoms were positioned geometrically and allowed to ride on their parent atoms, with C—H = 0.95 Å, and U_iso = 1.2–1.5 U_eq(parent atom).

Computing details

Data collection: APEX2 (Bruker, YEAR?); cell refinement: SMART (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXTL (Sheldrick, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. Perspective view of (I), showing 50% probability displacement ellipsoids for the non-H atoms.
	Fig. 2. Packing diagram of (I), viewed down the b axis, with C—H···Br contacts as broken lines.

3,4-Bis(4-bromophenyl)-2,5-diphenylcyclopenta-2,4-dienone

Crystal data

C29H18Br2O	F(000) = 1080
Mr = 542.25	Dx = 1.586 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 10.0677 (4) Å	Cell parameters from 5575 reflections
b = 9.6526 (4) Å	θ = 2.5–28.7°
c = 23.6791 (9) Å	µ = 3.59 mm^−1
β = 99.193 (2)°	T = 93 K
V = 2271.57 (16) Å^3	Plate, dark-violet
Z = 4	0.20 × 0.19 × 0.18 mm

Data collection

Bruker KappaCCD APEXII area-detector diffractometer	3999 independent reflections
Radiation source: fine-focus sealed tube	3578 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.024
φ and ω scans	θmax = 25.0°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	h = −11→11
Tmin = 0.534, Tmax = 0.564	k = −11→11
21955 measured reflections	l = −23→28

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)] = 0.019	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.047	H-atom parameters constrained
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0196P)^2 + 1.357P] where P = (Fo^2 + 2Fc^2)/3
3999 reflections	(Δ/σ)max = 0.002
289 parameters	Δρmax = 0.34 e Å^−3
0 restraints	Δρmin = −0.26 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
O1	1.11380 (13)	0.81448 (14)	0.50405 (5)	0.0234 (3)
Br1	0.453140 (18)	0.255240 (19)	0.278725 (8)	0.02000 (6)
Br2	1.088680 (19)	0.50624 (2)	0.125864 (7)	0.02318 (6)
C1	1.06412 (18)	0.74769 (18)	0.46290 (7)	0.0171 (4)
C2	0.92780 (18)	0.67815 (18)	0.45385 (7)	0.0156 (4)
C3	0.91426 (18)	0.61459 (18)	0.40263 (7)	0.0152 (4)
C4	1.03677 (18)	0.64253 (18)	0.37486 (7)	0.0147 (4)
C5	1.12617 (18)	0.71972 (18)	0.40982 (7)	0.0155 (4)
C6	1.25237 (18)	0.78587 (18)	0.39981 (7)	0.0156 (4)
C7	1.26415 (19)	0.84047 (18)	0.34603 (8)	0.0173 (4)
H7	1.1912	0.8320	0.3154	0.021*
C8	1.38078 (19)	0.90662 (19)	0.33701 (8)	0.0203 (4)
H8	1.3872	0.9434	0.3003	0.024*
C9	1.48880 (19)	0.91968 (19)	0.38138 (8)	0.0220 (4)
H9	1.5690	0.9647	0.3750	0.026*
C10	1.47859 (19)	0.86662 (19)	0.43476 (8)	0.0217 (4)
H10	1.5521	0.8753	0.4651	0.026*
C11	1.36124 (19)	0.80057 (19)	0.44427 (8)	0.0187 (4)
H11	1.3550	0.7652	0.4812	0.022*
C12	0.83491 (18)	0.68419 (19)	0.49612 (7)	0.0154 (4)
C13	0.82388 (18)	0.80643 (19)	0.52658 (7)	0.0178 (4)
H13	0.8795	0.8833	0.5213	0.021*
C14	0.73240 (19)	0.8167 (2)	0.56443 (8)	0.0203 (4)
H14	0.7259	0.9002	0.5850	0.024*
C15	0.65065 (19)	0.7056 (2)	0.57225 (8)	0.0217 (4)
H15	0.5871	0.7133	0.5977	0.026*
C16	0.6614 (2)	0.5828 (2)	0.54287 (8)	0.0220 (4)
H16	0.6057	0.5062	0.5484	0.026*
C17	0.75368 (19)	0.57192 (19)	0.50535 (7)	0.0186 (4)
H17	0.7616	0.4872	0.4857	0.022*
C18	0.80114 (18)	0.52985 (18)	0.37389 (7)	0.0142 (4)
C19	0.66960 (18)	0.58029 (18)	0.36437 (7)	0.0162 (4)
H19	0.6517	0.6704	0.3774	0.019*
C20	0.56437 (18)	0.50109 (19)	0.33620 (8)	0.0173 (4)
H20	0.4751	0.5363	0.3296	0.021*
C21	0.59257 (18)	0.36977 (18)	0.31805 (7)	0.0153 (4)
C22	0.72124 (19)	0.31713 (19)	0.32679 (8)	0.0217 (4)
H22	0.7383	0.2267	0.3138	0.026*
C23	0.82536 (19)	0.39715 (19)	0.35460 (8)	0.0211 (4)
H23	0.9144	0.3614	0.3606	0.025*
C24	1.04490 (18)	0.59994 (18)	0.31555 (7)	0.0147 (4)
C25	0.94423 (18)	0.63988 (19)	0.27082 (7)	0.0173 (4)
H25	0.8671	0.6873	0.2793	0.021*
C26	0.95508 (18)	0.61145 (19)	0.21434 (8)	0.0183 (4)
H26	0.8871	0.6404	0.1841	0.022*
C27	1.06679 (19)	0.54023 (18)	0.20290 (7)	0.0166 (4)
C28	1.16667 (18)	0.49671 (18)	0.24641 (8)	0.0171 (4)
H28	1.2422	0.4469	0.2377	0.021*
C29	1.15549 (18)	0.52640 (18)	0.30265 (8)	0.0164 (4)
H29	1.2236	0.4965	0.3327	0.020*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0216 (7)	0.0311 (8)	0.0170 (7)	−0.0036 (6)	0.0015 (6)	−0.0078 (6)
Br1	0.01865 (11)	0.01994 (11)	0.02038 (10)	−0.00453 (8)	−0.00005 (7)	−0.00154 (7)
Br2	0.02779 (12)	0.02861 (11)	0.01347 (10)	−0.00723 (9)	0.00428 (8)	−0.00567 (8)
C1	0.0184 (10)	0.0169 (9)	0.0155 (9)	0.0032 (8)	0.0011 (8)	0.0006 (8)
C2	0.0164 (10)	0.0137 (9)	0.0162 (9)	0.0014 (8)	0.0011 (7)	0.0006 (7)
C3	0.0160 (10)	0.0143 (9)	0.0154 (9)	0.0033 (7)	0.0022 (7)	0.0019 (7)
C4	0.0150 (9)	0.0132 (9)	0.0155 (9)	0.0035 (7)	0.0013 (7)	0.0008 (7)
C5	0.0153 (9)	0.0164 (9)	0.0144 (9)	0.0035 (7)	0.0010 (7)	0.0017 (7)
C6	0.0151 (10)	0.0145 (9)	0.0174 (9)	0.0028 (7)	0.0029 (7)	−0.0028 (7)
C7	0.0199 (10)	0.0149 (9)	0.0169 (9)	0.0012 (8)	0.0023 (7)	−0.0028 (7)
C8	0.0268 (11)	0.0171 (9)	0.0187 (9)	0.0013 (8)	0.0091 (8)	−0.0024 (8)
C9	0.0176 (10)	0.0192 (10)	0.0311 (11)	−0.0013 (8)	0.0096 (8)	−0.0034 (8)
C10	0.0161 (10)	0.0218 (10)	0.0261 (10)	0.0027 (8)	−0.0001 (8)	−0.0042 (8)
C11	0.0198 (10)	0.0183 (9)	0.0180 (9)	0.0021 (8)	0.0030 (8)	0.0000 (7)
C12	0.0147 (9)	0.0197 (9)	0.0111 (8)	0.0032 (8)	−0.0006 (7)	0.0005 (7)
C13	0.0165 (10)	0.0193 (9)	0.0168 (9)	−0.0010 (8)	0.0002 (7)	−0.0007 (7)
C14	0.0212 (10)	0.0239 (10)	0.0148 (9)	0.0049 (8)	0.0003 (8)	−0.0040 (8)
C15	0.0201 (10)	0.0320 (11)	0.0138 (9)	0.0041 (9)	0.0052 (8)	0.0026 (8)
C16	0.0247 (11)	0.0247 (10)	0.0167 (9)	−0.0027 (9)	0.0039 (8)	0.0053 (8)
C17	0.0249 (11)	0.0167 (9)	0.0140 (9)	0.0025 (8)	0.0026 (8)	0.0008 (7)
C18	0.0168 (10)	0.0149 (9)	0.0114 (9)	−0.0007 (7)	0.0033 (7)	0.0011 (7)
C19	0.0200 (10)	0.0138 (9)	0.0155 (9)	0.0021 (8)	0.0049 (7)	−0.0012 (7)
C20	0.0142 (9)	0.0202 (10)	0.0180 (9)	0.0024 (8)	0.0037 (7)	0.0028 (7)
C21	0.0165 (10)	0.0165 (9)	0.0127 (9)	−0.0046 (8)	0.0013 (7)	0.0006 (7)
C22	0.0224 (11)	0.0154 (10)	0.0267 (10)	0.0025 (8)	0.0025 (8)	−0.0055 (8)
C23	0.0139 (10)	0.0204 (10)	0.0282 (11)	0.0042 (8)	0.0013 (8)	−0.0031 (8)
C24	0.0156 (9)	0.0133 (9)	0.0149 (9)	−0.0023 (7)	0.0018 (7)	−0.0008 (7)
C25	0.0157 (10)	0.0171 (9)	0.0192 (9)	0.0011 (8)	0.0029 (7)	−0.0004 (7)
C26	0.0168 (10)	0.0194 (10)	0.0169 (9)	−0.0025 (8)	−0.0027 (8)	0.0019 (7)
C27	0.0220 (10)	0.0147 (9)	0.0132 (9)	−0.0066 (8)	0.0036 (7)	−0.0025 (7)
C28	0.0164 (10)	0.0154 (9)	0.0205 (10)	−0.0004 (8)	0.0054 (8)	−0.0012 (7)
C29	0.0160 (10)	0.0159 (9)	0.0163 (9)	0.0001 (8)	−0.0010 (7)	0.0002 (7)

Geometric parameters (Å, º)

O1—C1	1.208 (2)	C14—C15	1.382 (3)
Br1—C21	1.9084 (17)	C14—H14	0.9500
Br2—C27	1.9006 (17)	C15—C16	1.387 (3)
C1—C2	1.512 (3)	C15—H15	0.9500
C1—C5	1.514 (2)	C16—C17	1.388 (3)
C2—C3	1.347 (2)	C16—H16	0.9500
C2—C12	1.476 (2)	C17—H17	0.9500
C3—C18	1.477 (2)	C18—C23	1.394 (3)
C3—C4	1.512 (2)	C18—C19	1.395 (3)
C4—C5	1.346 (3)	C19—C20	1.388 (3)
C4—C24	1.478 (2)	C19—H19	0.9500
C5—C6	1.475 (3)	C20—C21	1.382 (3)
C6—C11	1.400 (3)	C20—H20	0.9500
C6—C7	1.401 (2)	C21—C22	1.376 (3)
C7—C8	1.383 (3)	C22—C23	1.381 (3)
C7—H7	0.9500	C22—H22	0.9500
C8—C9	1.392 (3)	C23—H23	0.9500
C8—H8	0.9500	C24—C29	1.395 (3)
C9—C10	1.383 (3)	C24—C25	1.398 (2)
C9—H9	0.9500	C25—C26	1.386 (3)
C10—C11	1.392 (3)	C25—H25	0.9500
C10—H10	0.9500	C26—C27	1.381 (3)
C11—H11	0.9500	C26—H26	0.9500
C12—C17	1.396 (3)	C27—C28	1.385 (3)
C12—C13	1.397 (3)	C28—C29	1.384 (3)
C13—C14	1.388 (3)	C28—H28	0.9500
C13—H13	0.9500	C29—H29	0.9500
O1—C1—C2	126.91 (16)	C16—C15—H15	120.0
O1—C1—C5	126.30 (17)	C15—C16—C17	119.96 (18)
C2—C1—C5	106.78 (15)	C15—C16—H16	120.0
C3—C2—C12	130.15 (17)	C17—C16—H16	120.0
C3—C2—C1	106.79 (15)	C16—C17—C12	120.68 (17)
C12—C2—C1	123.06 (15)	C16—C17—H17	119.7
C2—C3—C18	128.82 (16)	C12—C17—H17	119.7
C2—C3—C4	109.77 (16)	C23—C18—C19	118.60 (16)
C18—C3—C4	121.41 (15)	C23—C18—C3	119.83 (16)
C5—C4—C24	127.24 (16)	C19—C18—C3	121.56 (16)
C5—C4—C3	110.06 (15)	C20—C19—C18	121.17 (16)
C24—C4—C3	122.44 (15)	C20—C19—H19	119.4
C4—C5—C6	130.49 (16)	C18—C19—H19	119.4
C4—C5—C1	106.56 (15)	C21—C20—C19	118.40 (17)
C6—C5—C1	122.44 (15)	C21—C20—H20	120.8
C11—C6—C7	118.40 (17)	C19—C20—H20	120.8
C11—C6—C5	120.93 (16)	C22—C21—C20	121.80 (17)
C7—C6—C5	120.62 (16)	C22—C21—Br1	117.45 (13)
C8—C7—C6	120.76 (17)	C20—C21—Br1	120.75 (14)
C8—C7—H7	119.6	C21—C22—C23	119.32 (17)
C6—C7—H7	119.6	C21—C22—H22	120.3
C7—C8—C9	120.38 (18)	C23—C22—H22	120.3
C7—C8—H8	119.8	C22—C23—C18	120.71 (17)
C9—C8—H8	119.8	C22—C23—H23	119.6
C10—C9—C8	119.55 (18)	C18—C23—H23	119.6
C10—C9—H9	120.2	C29—C24—C25	118.80 (16)
C8—C9—H9	120.2	C29—C24—C4	121.12 (16)
C9—C10—C11	120.43 (18)	C25—C24—C4	119.98 (16)
C9—C10—H10	119.8	C26—C25—C24	121.12 (17)
C11—C10—H10	119.8	C26—C25—H25	119.4
C10—C11—C6	120.49 (17)	C24—C25—H25	119.4
C10—C11—H11	119.8	C27—C26—C25	118.67 (17)
C6—C11—H11	119.8	C27—C26—H26	120.7
C17—C12—C13	118.57 (16)	C25—C26—H26	120.7
C17—C12—C2	121.74 (16)	C26—C27—C28	121.49 (16)
C13—C12—C2	119.66 (16)	C26—C27—Br2	119.80 (14)
C14—C13—C12	120.64 (17)	C28—C27—Br2	118.67 (14)
C14—C13—H13	119.7	C29—C28—C27	119.46 (17)
C12—C13—H13	119.7	C29—C28—H28	120.3
C15—C14—C13	120.14 (17)	C27—C28—H28	120.3
C15—C14—H14	119.9	C28—C29—C24	120.42 (17)
C13—C14—H14	119.9	C28—C29—H29	119.8
C14—C15—C16	119.99 (17)	C24—C29—H29	119.8
C14—C15—H15	120.0
O1—C1—C2—C3	−179.45 (18)	C17—C12—C13—C14	−1.1 (3)
C5—C1—C2—C3	1.50 (19)	C2—C12—C13—C14	176.79 (17)
O1—C1—C2—C12	0.1 (3)	C12—C13—C14—C15	−0.2 (3)
C5—C1—C2—C12	−178.90 (15)	C13—C14—C15—C16	1.0 (3)
C12—C2—C3—C18	−0.8 (3)	C14—C15—C16—C17	−0.4 (3)
C1—C2—C3—C18	178.75 (17)	C15—C16—C17—C12	−0.9 (3)
C12—C2—C3—C4	178.56 (17)	C13—C12—C17—C16	1.7 (3)
C1—C2—C3—C4	−1.88 (19)	C2—C12—C17—C16	−176.19 (17)
C2—C3—C4—C5	1.7 (2)	C2—C3—C18—C23	−126.7 (2)
C18—C3—C4—C5	−178.89 (16)	C4—C3—C18—C23	54.0 (2)
C2—C3—C4—C24	−172.90 (16)	C2—C3—C18—C19	54.6 (3)
C18—C3—C4—C24	6.5 (2)	C4—C3—C18—C19	−124.71 (18)
C24—C4—C5—C6	1.8 (3)	C23—C18—C19—C20	−0.2 (3)
C3—C4—C5—C6	−172.48 (17)	C3—C18—C19—C20	178.54 (16)
C24—C4—C5—C1	173.62 (16)	C18—C19—C20—C21	0.5 (3)
C3—C4—C5—C1	−0.63 (19)	C19—C20—C21—C22	−0.5 (3)
O1—C1—C5—C4	−179.53 (18)	C19—C20—C21—Br1	−179.71 (13)
C2—C1—C5—C4	−0.47 (19)	C20—C21—C22—C23	0.2 (3)
O1—C1—C5—C6	−6.9 (3)	Br1—C21—C22—C23	179.40 (14)
C2—C1—C5—C6	172.18 (16)	C21—C22—C23—C18	0.2 (3)
C4—C5—C6—C11	−147.57 (19)	C19—C18—C23—C22	−0.2 (3)
C1—C5—C6—C11	41.7 (3)	C3—C18—C23—C22	−178.92 (17)
C4—C5—C6—C7	35.0 (3)	C5—C4—C24—C29	56.6 (3)
C1—C5—C6—C7	−135.76 (18)	C3—C4—C24—C29	−129.80 (18)
C11—C6—C7—C8	0.3 (3)	C5—C4—C24—C25	−119.9 (2)
C5—C6—C7—C8	177.85 (16)	C3—C4—C24—C25	53.7 (2)
C6—C7—C8—C9	0.2 (3)	C29—C24—C25—C26	−2.1 (3)
C7—C8—C9—C10	−0.3 (3)	C4—C24—C25—C26	174.47 (17)
C8—C9—C10—C11	0.0 (3)	C24—C25—C26—C27	1.1 (3)
C9—C10—C11—C6	0.5 (3)	C25—C26—C27—C28	0.3 (3)
C7—C6—C11—C10	−0.7 (3)	C25—C26—C27—Br2	−177.38 (13)
C5—C6—C11—C10	−178.20 (16)	C26—C27—C28—C29	−0.8 (3)
C3—C2—C12—C17	35.5 (3)	Br2—C27—C28—C29	176.94 (13)
C1—C2—C12—C17	−144.03 (18)	C27—C28—C29—C24	−0.2 (3)
C3—C2—C12—C13	−142.4 (2)	C25—C24—C29—C28	1.6 (3)
C1—C2—C12—C13	38.1 (2)	C4—C24—C29—C28	−174.91 (16)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C28—H28···Br1^i	0.95	2.87	3.6920 (18)	146
C22—H22···Br2^ii	0.95	2.97	3.6386 (19)	129
C15—H15···Br1^iii	0.95	3.03	3.8556 (18)	146

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