Crystals of the title compound, C4H4Br2O4, were grown from an aqueous solution. The structure features centrosymmetric molecules, each of which forms hydrogen bonds with two adjacent acid molecules, yielding long chains.
Supporting information
CCDC reference: 296661
Key indicators
- Single-crystal X-ray study
- T = 298 K
- Mean
(C-C) = 0.013 Å
- R factor = 0.045
- wR factor = 0.102
- Data-to-parameter ratio = 18.1
checkCIF/PLATON results
No syntax errors found
Alert level B
PLAT230_ALERT_2_B Hirshfeld Test Diff for C1 - C2 .. 10.18 su
Alert level C
PLAT068_ALERT_1_C Reported F000 Differs from Calcd (or Missing)... ?
PLAT230_ALERT_2_C Hirshfeld Test Diff for Br1 - C2 .. 5.07 su
PLAT241_ALERT_2_C Check High Ueq as Compared to Neighbors for C2
PLAT341_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ... 13
PLAT360_ALERT_2_C Short C(sp3)-C(sp3) Bond C2 - C2_a ... 1.40 Ang.
PLAT431_ALERT_2_C Short Inter HL..A Contact Br1 .. O2 .. 3.25 Ang.
0 ALERT level A = In general: serious problem
1 ALERT level B = Potentially serious problem
6 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
5 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
0 ALERT type 4 Improvement, methodology, query or suggestion
checkCIF publication errors
Alert level A
PUBL022_ALERT_1_A There is a mismatched ~ on line 117
Crystals of (R,S)-2,3-dibromosuccinic acid, C~4#H~4~Br~2~O~4~, were grown from
If you require a ~ then it should be escaped
with a \, i.e. \~
Otherwise there must be a matching closing ~, e.g. C~2~H~4~
1 ALERT level A = Data missing that is essential or data in wrong format
0 ALERT level G = General alerts. Data that may be required is missing
An aqueous solution (2.5 ml) with the respective concentrations 0.69 mol l−1 of fumaric acid, 2.1 mol l−1 of KBr and 1.9 mol l−1 of Br2 was placed in a boiling water bath. To avoid precipitation of KBr, the volume of the solution was kept constant by addition of deionized water. After 10 min, crystals of (I) were vacuum-filtered and placed in a heated cabinet at 373 K for one hour.
The H atoms were located in a difference Fourier map and were refined using a riding model, with C—H = 0.96 Å and Uiso(H) = 1.2Ueq(C), and with O—H = 0.82 Å and Uiso(H) = 1.5Ueq(O).
Data collection: COLLECT (Nonius, 1999); cell refinement: DIRAX/LSQ (Duisenberg et al., 2003); data reduction: EVALCCD (Duisenberg, 1992); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 2005); software used to prepare material for publication: maXus (Mackay et al., 1999).
Crystal data top
C4H4Br2O4 | Z = 4 |
Mr = 275.89 | Dx = 2.477 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 37 reflections |
a = 14.244 (1) Å | θ = 4.3–21.0° |
b = 5.1664 (6) Å | µ = 10.91 mm−1 |
c = 11.3736 (8) Å | T = 298 K |
β = 117.684 (9)° | Cube, colourless |
V = 741.17 (13) Å3 | 0.33 × 0.30 × 0.27 mm |
Data collection top
Bruker–Nonius KappaCCD diffractometer | 679 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.039 |
ϕ scans | θmax = 27.5°, θmin = 4.5° |
Absorption correction: numerical HABITUS (Herrendorf & Bärnighausen, 1997) | h = −15→18 |
Tmin = 0.091, Tmax = 0.137 | k = −6→6 |
5265 measured reflections | l = −14→14 |
849 independent reflections | |
Refinement top
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)] = 0.045 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.102 | H-atom parameters constrained |
S = 1.08 | w = 1/[σ2(Fo2) + (0.0299P)2 + 8.0961P] where P = (Fo2 + 2Fc2)/3 |
849 reflections | (Δ/σ)max < 0.001 |
47 parameters | Δρmax = 1.14 e Å−3 |
0 restraints | Δρmin = −0.73 e Å−3 |
Crystal data top
C4H4Br2O4 | V = 741.17 (13) Å3 |
Mr = 275.89 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 14.244 (1) Å | µ = 10.91 mm−1 |
b = 5.1664 (6) Å | T = 298 K |
c = 11.3736 (8) Å | 0.33 × 0.30 × 0.27 mm |
β = 117.684 (9)° | |
Data collection top
Bruker–Nonius KappaCCD diffractometer | 849 independent reflections |
Absorption correction: numerical HABITUS (Herrendorf & Bärnighausen, 1997) | 679 reflections with I > 2σ(I) |
Tmin = 0.091, Tmax = 0.137 | Rint = 0.039 |
5265 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.045 | 0 restraints |
wR(F2) = 0.102 | H-atom parameters constrained |
S = 1.08 | Δρmax = 1.14 e Å−3 |
849 reflections | Δρmin = −0.73 e Å−3 |
47 parameters | |
Special details top
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 (Å2) top | x | y | z | Uiso*/Ueq | |
Br1 | 0.15304 (5) | 0.36080 (15) | 0.28052 (6) | 0.0568 (3) | |
O1 | 0.0918 (5) | −0.1270 (12) | 0.4481 (7) | 0.0808 (17) | |
H1 | 0.0395 | −0.1590 | 0.4580 | 0.121* | |
O2 | 0.0784 (4) | 0.2541 (10) | 0.5270 (5) | 0.0636 (13) | |
C1 | 0.1201 (5) | 0.0978 (18) | 0.4820 (8) | 0.065 (2) | |
C2 | 0.2153 (7) | 0.1680 (17) | 0.4492 (8) | 0.080 (2) | |
H2 | 0.2491 | 0.0147 | 0.4392 | 0.096* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Br1 | 0.0415 (3) | 0.0827 (5) | 0.0441 (4) | 0.0038 (3) | 0.0182 (3) | 0.0114 (3) |
O1 | 0.077 (4) | 0.073 (4) | 0.130 (5) | 0.002 (3) | 0.079 (4) | 0.007 (3) |
O2 | 0.052 (3) | 0.057 (3) | 0.074 (3) | −0.021 (2) | 0.023 (2) | −0.004 (3) |
C1 | 0.035 (3) | 0.083 (6) | 0.084 (5) | 0.003 (4) | 0.033 (3) | 0.025 (4) |
C2 | 0.089 (6) | 0.074 (6) | 0.069 (5) | 0.016 (4) | 0.030 (4) | −0.003 (4) |
Geometric parameters (Å, º) top
Br1—C2 | 1.969 (8) | C1—C2 | 1.605 (11) |
O1—C1 | 1.229 (10) | C2—C2i | 1.403 (16) |
O1—H1 | 0.8200 | C2—H2 | 0.9600 |
O2—C1 | 1.244 (9) | | |
| | | |
C1—O1—H1 | 109.5 | C2i—C2—Br1 | 108.9 (8) |
O1—C1—O2 | 126.1 (6) | C1—C2—Br1 | 107.1 (5) |
O1—C1—C2 | 109.2 (7) | C2i—C2—H2 | 113.1 |
O2—C1—C2 | 124.5 (7) | C1—C2—H2 | 111.5 |
C2i—C2—C1 | 107.1 (9) | Br1—C2—H2 | 108.9 |
Symmetry code: (i) −x+1/2, −y+1/2, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O2ii | 0.82 | 1.83 | 2.650 (7) | 175 |
Symmetry code: (ii) −x, −y, −z+1. |
Experimental details
Crystal data |
Chemical formula | C4H4Br2O4 |
Mr | 275.89 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 298 |
a, b, c (Å) | 14.244 (1), 5.1664 (6), 11.3736 (8) |
β (°) | 117.684 (9) |
V (Å3) | 741.17 (13) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 10.91 |
Crystal size (mm) | 0.33 × 0.30 × 0.27 |
|
Data collection |
Diffractometer | Bruker–Nonius KappaCCD diffractometer |
Absorption correction | Numerical HABITUS (Herrendorf & Bärnighausen, 1997) |
Tmin, Tmax | 0.091, 0.137 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5265, 849, 679 |
Rint | 0.039 |
(sin θ/λ)max (Å−1) | 0.650 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.045, 0.102, 1.08 |
No. of reflections | 849 |
No. of parameters | 47 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 1.14, −0.73 |
Selected bond lengths (Å) topBr1—C2 | 1.969 (8) | C1—C2 | 1.605 (11) |
O1—C1 | 1.229 (10) | C2—C2i | 1.403 (16) |
O2—C1 | 1.244 (9) | | |
Symmetry code: (i) −x+1/2, −y+1/2, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O2ii | 0.82 | 1.83 | 2.650 (7) | 175 |
Symmetry code: (ii) −x, −y, −z+1. |
Some time ago, the structure of racemic 2,3-dibromosuccinic acid, which had been obtained by an electrophilic reaction between maleic acid and bromine, was determined (Bolte & Degen, 2000). The structure features a complex pattern of hydrogen bonds between carboxy groups of adjacent acid molecules. Inspired by the fact that the melting points of the racemic and the meso compounds are extremely different (racemate: 444 K; meso compound: 528 K), we expected very different hydrogen-bonding patterns in the two phases and decided therefore to determine the structure of the meso compound. From a reaction between bromine and fumaric acid, we obtained single crystals of the meso compound, (I), whose structure is described here. The molecule lies about an inversion centre located at the mid-point of the C2—C2i bond [symmetry code: (i) 1/2 − x, 1/2 − y, 1 − z). The geometry of the molecule is essentially the same as in the structure of pyridone.(R,S)-2,3-dibromosuccinic acid (1:1) (Aakeröy et al., 2000). In the crystal structure, the carboxy groups link pairs of molecules, forming an inversion-related closed hydrogen-bonding loop and infinite chains along the a axis (Fig 2).