1,4-Dibromo-butane-2,3-dione.

The asymmetric unit of the title compound, C(4)H(4)Br(2)O(2), contains one half-mol-ecule, being located about a centre of inversion. In the crystal, there are no significant inter-molecular inter-actions.

Related literature

For the uses of 1,4-dibromo­butane-2,3-dione, see: Gogte et al. (1967 ▶). For the synthesis of 1,4-dibromo­butane-2,3-dione, see: Ruggli & Herzog (1946 ▶). For the cystal structure of the 1,4-di­chloro analogue, see: Ducourant et al. (1986 ▶). For bond–length data, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C4H4Br2O2

M = 243.89

Orthorhombic,

a = 6.945 (1) Å

b = 5.542 (1) Å

c = 17.238 (3) Å

V = 663.5 (2) Å3

Z = 4

Mo Kα radiation

μ = 12.13 mm−1

T = 298 K

0.10 × 0.10 × 0.10 mm

Data collection

Enraf–Nonius CAD-4 diffractometer

Absorption correction: ψ scan (North et al., 1968 ▶) T min = 0.195, T max = 0.377

614 measured reflections

614 independent reflections

319 reflections with I > 2σ(I)

R int = 0.077

3 standard reflections every 120 min intensity decay: 1%

Refinement

R[F 2 > 2σ(F 2)] = 0.065

wR(F 2) = 0.108

S = 0.93

614 reflections

37 parameters

1 restraint

H-atom parameters constrained

Δρmax = 0.65 e Å−3

Δρmin = −0.60 e Å−3

Data collection: CAD-4 Software (Enraf–Nonius, 1985 ▶); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995 ▶); 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.

Click here for additional data file.

Crystal structure: contains datablock(s) I, global, n1. DOI: 10.1107/S1600536812044200/su2517sup1.cif

Click here for additional data file.

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812044200/su2517Isup2.hkl

Click here for additional data file.

Supplementary material file. DOI: 10.1107/S1600536812044200/su2517Isup3.cml

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

C4H4Br2O2	Dx = 2.442 Mg m−3
Mr = 243.89	Melting point < 395 K
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 25 reflections
a = 6.945 (1) Å	θ = 9–14°
b = 5.542 (1) Å	µ = 12.13 mm−1
c = 17.238 (3) Å	T = 298 K
V = 663.5 (2) Å3	Cube, yellow
Z = 4	0.10 × 0.10 × 0.10 mm
F(000) = 456

Enraf–Nonius CAD-4 diffractometer	319 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.077
Graphite monochromator	θmax = 25.4°, θmin = 2.4°
ω/2θ scans	h = 0→8
Absorption correction: ψ scan (North et al., 1968)	k = −6→6
Tmin = 0.195, Tmax = 0.377	l = −20→20
614 measured reflections	3 standard reflections every 120 min
614 independent reflections	intensity decay: 1%

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)] = 0.065	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.108	H-atom parameters constrained
S = 0.93	w = 1/[σ2(Fo2) + (0.P)2] where P = (Fo2 + 2Fc2)/3
614 reflections	(Δ/σ)max < 0.001
37 parameters	Δρmax = 0.65 e Å−3
1 restraint	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.

	x	y	z	Uiso*/Ueq
Br	0.96430 (19)	0.17863 (19)	0.67746 (8)	0.0634 (5)
O	0.8640 (13)	0.2368 (15)	0.5056 (4)	0.062 (2)
C1	1.0276 (16)	0.4425 (18)	0.6134 (6)	0.055 (3)
H1A	0.9689	0.5875	0.6342	0.066*
H1B	1.1661	0.4652	0.6138	0.066*
C2	0.9577 (15)	0.4056 (11)	0.5267 (6)	0.039 (2)

	U11	U22	U33	U12	U13	U23
Br	0.0755 (7)	0.0501 (7)	0.0647 (9)	−0.0027 (7)	0.0041 (7)	0.0097 (6)
O	0.076 (5)	0.036 (3)	0.073 (6)	−0.026 (5)	−0.019 (5)	0.007 (3)
C1	0.045 (6)	0.068 (7)	0.052 (7)	0.000 (6)	0.009 (6)	−0.016 (7)
C2	0.033 (5)	0.028 (4)	0.057 (7)	0.013 (6)	0.023 (5)	0.007 (5)

Br—C1	1.885 (10)	C1—H1A	0.9700
O—C2	1.196 (11)	C1—H1B	0.9700
C1—C2	1.585 (9)	C2—C2i	1.512 (16)
C2—C1—Br	112.4 (6)	H1A—C1—H1B	107.9
C2—C1—H1A	109.1	O—C2—C2i	124.6 (12)
Br—C1—H1A	109.1	O—C2—C1	123.7 (8)
C2—C1—H1B	109.1	C2i—C2—C1	111.4 (10)
Br—C1—H1B	109.1
Br—C1—C2—O	4.7 (13)	Br—C1—C2—C2i	−169.0 (8)