4,12-Bis(2,2-dibromo-vinyl)[2.2]paracyclo-phane.

In the title compound, C(20)H(16)Br(4), both vinylic substituents were introduced by a Corey-Fuchs reaction using 4,12-diform-yl[2.2]paracyclo-phane as starting material. The title compound may be used as a valuable precursor for the synthesis of diethyn-yl[2.2]paracyclo-phane. The title mol-ecule is centrosymmetric with a crystallographic center of inversion between the centers of the two phenyl rings. A strong tilting is observed with an inter-planar angle between the best aromatic plane and the vinyl plane of 49.4 (5)°. No significant inter-molecular inter-actions are found in the crystal.

Related literature

For related structures of halovinyl compounds, see: Clément et al. (2007a ▶,b ▶); Jones et al. (1993 ▶); Hua et al. (2006 ▶). For ethynyl-functionalized[2.2]paracyclo­phanes, see: Jones et al. (2007 ▶). For the Corey–Fuchs reaction, see: Corey et al. (1972 ▶). For applications of [2.2]paracyclo­phanes, see: Hopf et al. (2008 ▶). For an alternative to the classical Sonogashira synthesis, see: Morisaki et al. (2003 ▶).

Experimental

Crystal data

C20H16Br4

M = 575.97

Orthorhombic,

a = 12.155 (1) Å

b = 8.3819 (9) Å

c = 18.335 (2) Å

V = 1867.9 (3) Å3

Z = 4

Mo Kα radiation

μ = 8.62 mm−1

T = 173 (2) K

0.30 × 0.20 × 0.10 mm

Data collection

Bruker APEX CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 1999 ▶) T min = 0.141, T max = 0.418

16030 measured reflections

2043 independent reflections

1766 reflections with I > 2σ(I)

R int = 0.045

Refinement

R[F 2 > 2σ(F 2)] = 0.032

wR(F 2) = 0.073

S = 1.08

2043 reflections

109 parameters

H-atom parameters constrained

Δρmax = 0.84 e Å−3

Δρmin = −0.60 e Å−3

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT-Plus (Bruker, 2001 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809002475/im2094sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809002475/im2094Isup2.hkl

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

C20H16Br4	Dx = 2.048 Mg m−3
Mr = 575.97	Melting point: 456 K
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 1766 reflections
a = 12.155 (1) Å	θ = 2.2–27.0°
b = 8.3819 (9) Å	µ = 8.62 mm−1
c = 18.335 (2) Å	T = 173 K
V = 1867.9 (3) Å3	Irregular, white
Z = 4	0.30 × 0.20 × 0.10 mm
F(000) = 1104

Bruker APEX CCD diffractometer	2043 independent reflections
Radiation source: fine-focus sealed tube	1766 reflections with I > 2σ(I)
graphite	Rint = 0.045
CCD scans	θmax = 27.0°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 1999)	h = −15→15
Tmin = 0.141, Tmax = 0.418	k = −10→10
16030 measured reflections	l = −23→23

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.032	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.073	H-atom parameters constrained
S = 1.08	w = 1/[σ2(Fo2) + (0.0298P)2 + 3.2824P] where P = (Fo2 + 2Fc2)/3
2043 reflections	(Δ/σ)max = 0.001
109 parameters	Δρmax = 0.84 e Å−3
0 restraints	Δρmin = −0.60 e Å−3

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.

	x	y	z	Uiso*/Ueq
Br1	0.94392 (3)	0.12568 (5)	0.72066 (2)	0.03823 (13)
Br2	1.18942 (3)	0.01277 (4)	0.70021 (2)	0.03403 (12)
C1	1.0695 (3)	0.1284 (4)	0.66105 (19)	0.0223 (7)
C2	1.0750 (3)	0.1954 (4)	0.59555 (18)	0.0216 (7)
H2	1.1423	0.1819	0.5699	0.026*
C3	0.9893 (3)	0.2882 (4)	0.55781 (18)	0.0198 (6)
C4	0.9745 (3)	0.2705 (4)	0.48219 (18)	0.0215 (7)
C5	0.8859 (3)	0.3511 (4)	0.45039 (19)	0.0250 (7)
H5	0.8626	0.3226	0.4027	0.030*
C6	0.8316 (3)	0.4717 (4)	0.4873 (2)	0.0241 (7)
H6	0.7720	0.5255	0.4645	0.029*
C7	0.8632 (3)	0.5151 (4)	0.55752 (19)	0.0227 (7)
C8	0.9336 (3)	0.4115 (4)	0.59427 (18)	0.0213 (7)
H8	0.9442	0.4246	0.6453	0.026*
C9	0.8418 (3)	0.6819 (4)	0.5856 (2)	0.0280 (8)
H9A	0.8312	0.6778	0.6391	0.034*
H9B	0.7729	0.7228	0.5636	0.034*
C10	1.0610 (3)	0.1987 (4)	0.43258 (19)	0.0263 (7)
H10A	1.0256	0.1650	0.3864	0.032*
H10B	1.0918	0.1023	0.4562	0.032*

	U11	U22	U33	U12	U13	U23
Br1	0.0365 (2)	0.0460 (2)	0.0321 (2)	0.01147 (17)	0.01440 (17)	0.01208 (17)
Br2	0.0273 (2)	0.0414 (2)	0.0335 (2)	0.00426 (16)	−0.00318 (15)	0.01310 (16)
C1	0.0172 (15)	0.0229 (15)	0.0267 (17)	0.0017 (13)	−0.0003 (13)	−0.0005 (13)
C2	0.0174 (15)	0.0218 (15)	0.0256 (17)	0.0000 (12)	0.0026 (13)	0.0015 (13)
C3	0.0163 (15)	0.0181 (15)	0.0251 (17)	−0.0045 (12)	0.0000 (13)	0.0023 (12)
C4	0.0238 (17)	0.0148 (14)	0.0260 (17)	−0.0054 (12)	−0.0006 (13)	−0.0006 (12)
C5	0.0257 (17)	0.0270 (17)	0.0223 (18)	−0.0090 (14)	−0.0035 (14)	0.0024 (13)
C6	0.0173 (16)	0.0240 (16)	0.0309 (19)	−0.0051 (13)	−0.0015 (14)	0.0065 (14)
C7	0.0182 (16)	0.0245 (16)	0.0254 (18)	−0.0033 (13)	0.0047 (13)	0.0034 (13)
C8	0.0198 (16)	0.0228 (16)	0.0212 (16)	−0.0022 (13)	0.0011 (13)	0.0024 (12)
C9	0.0298 (18)	0.0275 (17)	0.0266 (19)	0.0080 (14)	0.0060 (15)	0.0040 (14)
C10	0.0342 (19)	0.0224 (15)	0.0223 (17)	−0.0003 (14)	−0.0004 (15)	−0.0027 (13)

Br1—C1	1.878 (3)	C6—C7	1.392 (5)
Br2—C1	1.892 (3)	C6—H6	0.9500
C1—C2	1.328 (5)	C7—C8	1.392 (4)
C2—C3	1.473 (4)	C7—C9	1.512 (5)
C2—H2	0.9500	C8—H8	0.9500
C3—C8	1.405 (4)	C9—C10i	1.584 (5)
C3—C4	1.406 (5)	C9—H9A	0.9900
C4—C5	1.399 (5)	C9—H9B	0.9900
C4—C10	1.515 (5)	C10—C9i	1.584 (5)
C5—C6	1.385 (5)	C10—H10A	0.9900
C5—H5	0.9500	C10—H10B	0.9900
C2—C1—Br1	124.9 (2)	C6—C7—C8	117.0 (3)
C2—C1—Br2	121.4 (2)	C6—C7—C9	120.5 (3)
Br1—C1—Br2	113.53 (17)	C8—C7—C9	121.2 (3)
C1—C2—C3	127.8 (3)	C7—C8—C3	121.6 (3)
C1—C2—H2	116.1	C7—C8—H8	119.2
C3—C2—H2	116.1	C3—C8—H8	119.2
C8—C3—C4	119.0 (3)	C7—C9—C10i	112.6 (3)
C8—C3—C2	120.4 (3)	C7—C9—H9A	109.1
C4—C3—C2	119.9 (3)	C10i—C9—H9A	109.1
C5—C4—C3	117.3 (3)	C7—C9—H9B	109.1
C5—C4—C10	118.4 (3)	C10i—C9—H9B	109.1
C3—C4—C10	123.0 (3)	H9A—C9—H9B	107.8
C6—C5—C4	121.1 (3)	C4—C10—C9i	113.1 (3)
C6—C5—H5	119.5	C4—C10—H10A	109.0
C4—C5—H5	119.5	C9i—C10—H10A	109.0
C5—C6—C7	120.7 (3)	C4—C10—H10B	109.0
C5—C6—H6	119.6	C9i—C10—H10B	109.0
C7—C6—H6	119.6	H10A—C10—H10B	107.8