2-Bromo­fumaric acid

Single crystals of 2-bromo­fumaric acid, C₄H₃BrO₄, were obtained from an aqueous solution of racemic 2,3-dibromo­succinic acid and (−)-quinine. The title compound crystallizes with two mol­ecules in the asymmetric unit. The structure is stabilized by O—H...O hydrogen bonds forming alternating chains.

Key indicators

• Single-crystal X-ray study
• T = 299 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.037
• wR factor = 0.072
• Data-to-parameter ratio = 16.2

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.42
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.44
PLAT701_ALERT_1_C Bond    Calc    1.865(3), Rep    1.861(3), Dev..       1.33 Sigma
              BR1  -C2      1.555   1.555

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 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
   2 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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Computing details

Data collection: COLLECT (Nonius, 1999); cell refinement: DIRAX/LSQ (Duisenberg, 1992); data reduction: EVALCCD (Duisenberg et al., 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: maXus (Mackay et al., 1999).

2-Bromofumaric acid

Crystal data

C4H3BrO4	Z = 4
Mr = 194.97	F(000) = 376
Triclinic, P1	Dx = 2.188 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.8290 (4) Å	Cell parameters from 60 reflections
b = 8.3791 (4) Å	θ = 4.3–22.0°
c = 10.2443 (3) Å	µ = 6.88 mm^−1
α = 69.572 (4)°	T = 299 K
β = 70.383 (3)°	Fragment, colourless
γ = 79.963 (4)°	0.30 × 0.30 × 0.30 mm
V = 591.97 (5) Å^3

Data collection

Bruker Nonius KappaCCD area-detector diffractometer	1821 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.052
φ and ω scans	θmax = 27.5°, θmin = 4.5°
Absorption correction: numerical (Herrendorf & Bärnighausen, 1997)	h = −10→10
Tmin = 0.581, Tmax = 0.661	k = −10→10
11936 measured reflections	l = −13→12
2701 independent reflections

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)] = 0.037	H-atom parameters constrained
wR(F^2) = 0.072	w = 1/[σ^2(Fo^2) + (0.0231P)^2 + 0.495P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max < 0.001
2701 reflections	Δρmax = 0.33 e Å^−3
167 parameters	Δρmin = −0.44 e Å^−3
0 restraints

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
Br2	0.65543 (6)	0.05029 (6)	0.59519 (4)	0.06076 (16)
Br1	0.56894 (5)	0.50250 (5)	0.68940 (4)	0.05132 (14)
O8	0.7533 (4)	0.1438 (3)	0.2636 (3)	0.0534 (7)
C2	0.4980 (4)	0.3307 (4)	0.8676 (3)	0.0342 (8)
C4	0.2319 (5)	0.2437 (5)	0.8299 (4)	0.0372 (8)
O7	0.9082 (4)	0.3746 (4)	0.1279 (3)	0.0559 (7)
C8	0.8514 (5)	0.2514 (5)	0.2480 (4)	0.0402 (8)
C3	0.3572 (4)	0.2377 (4)	0.9116 (4)	0.0358 (8)
O6	0.8979 (3)	0.1258 (3)	0.7387 (2)	0.0482 (7)
O4	0.1034 (4)	0.1408 (4)	0.9054 (3)	0.0553 (7)
O1	0.7273 (4)	0.4053 (3)	0.9363 (3)	0.0523 (7)
C5	0.9442 (5)	0.2002 (5)	0.6086 (4)	0.0369 (8)
C6	0.8569 (5)	0.1816 (4)	0.5055 (4)	0.0369 (8)
O2	0.5820 (4)	0.1726 (4)	1.0752 (3)	0.0620 (8)
C7	0.9219 (5)	0.2552 (5)	0.3632 (4)	0.0393 (8)
O5	1.0728 (4)	0.3031 (4)	0.5434 (3)	0.0639 (8)
C1	0.6154 (5)	0.3058 (5)	0.9637 (4)	0.0376 (8)
O3	0.2492 (4)	0.3336 (4)	0.7044 (3)	0.0615 (8)
H7O	0.8624	0.3720	0.0675	0.084*
H3	0.3296	0.1537	1.0068	0.043*
H4	0.0409	0.1432	0.8545	0.083*
H2	0.6474	0.1655	1.1253	0.093*
H7	1.0273	0.3166	0.3377	0.047*
H5	1.1256	0.3006	0.6011	0.096*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br2	0.0524 (3)	0.0857 (4)	0.0506 (2)	−0.0289 (2)	−0.01035 (19)	−0.0224 (2)
Br1	0.0495 (2)	0.0573 (3)	0.0433 (2)	−0.01669 (19)	−0.01746 (18)	−0.00144 (18)
O8	0.0680 (18)	0.0545 (17)	0.0518 (15)	−0.0154 (15)	−0.0354 (14)	−0.0115 (13)
C2	0.0372 (19)	0.040 (2)	0.0298 (16)	−0.0034 (16)	−0.0118 (15)	−0.0135 (15)
C4	0.0379 (19)	0.043 (2)	0.0383 (19)	−0.0073 (17)	−0.0154 (16)	−0.0160 (17)
O7	0.0632 (18)	0.076 (2)	0.0339 (13)	−0.0234 (15)	−0.0233 (13)	−0.0058 (14)
C8	0.038 (2)	0.050 (2)	0.039 (2)	−0.0019 (18)	−0.0176 (16)	−0.0172 (18)
C3	0.0385 (19)	0.039 (2)	0.0351 (17)	−0.0064 (16)	−0.0147 (15)	−0.0124 (15)
O6	0.0477 (15)	0.0671 (18)	0.0335 (13)	−0.0155 (13)	−0.0165 (11)	−0.0104 (12)
O4	0.0502 (16)	0.0739 (19)	0.0502 (15)	−0.0276 (15)	−0.0230 (13)	−0.0106 (14)
O1	0.0561 (16)	0.0621 (18)	0.0481 (14)	−0.0235 (14)	−0.0271 (13)	−0.0080 (13)
C5	0.0360 (19)	0.044 (2)	0.0365 (18)	−0.0016 (17)	−0.0176 (16)	−0.0139 (16)
C6	0.0355 (19)	0.040 (2)	0.0421 (19)	−0.0028 (16)	−0.0172 (16)	−0.0158 (16)
O2	0.084 (2)	0.0598 (19)	0.0561 (17)	−0.0280 (16)	−0.0477 (16)	0.0023 (14)
C7	0.040 (2)	0.049 (2)	0.0375 (19)	−0.0053 (17)	−0.0203 (16)	−0.0136 (17)
O5	0.074 (2)	0.087 (2)	0.0383 (14)	−0.0440 (18)	−0.0270 (14)	−0.0014 (14)
C1	0.040 (2)	0.043 (2)	0.0349 (18)	−0.0065 (17)	−0.0130 (15)	−0.0149 (16)
O3	0.0688 (19)	0.077 (2)	0.0478 (16)	−0.0343 (16)	−0.0315 (14)	−0.0025 (15)

Geometric parameters (Å, º)

Br2—C6	1.860 (3)	O1—C1	1.210 (4)
Br1—C2	1.861 (3)	C5—O5	1.284 (4)
O8—C8	1.217 (4)	C5—C6	1.497 (4)
C2—C3	1.320 (4)	C6—C7	1.321 (5)
C2—C1	1.500 (4)	O2—C1	1.274 (4)
C4—O3	1.216 (4)	O7—H7O	0.8200
C4—O4	1.290 (4)	C3—H3	0.9600
C4—C3	1.472 (4)	O4—H4	0.8200
O7—C8	1.295 (4)	O2—H2	0.8200
C8—C7	1.472 (4)	C7—H7	0.9601
O6—C5	1.212 (4)	O5—H5	0.8200
C3—C2—C1	120.9 (3)	C7—C6—Br2	124.7 (3)
C3—C2—Br1	125.3 (2)	C5—C6—Br2	114.5 (2)
C1—C2—Br1	113.8 (2)	C6—C7—C8	127.6 (3)
O3—C4—O4	123.7 (3)	O1—C1—O2	124.9 (3)
O3—C4—C3	123.8 (3)	O1—C1—C2	122.1 (3)
O4—C4—C3	112.5 (3)	O2—C1—C2	112.9 (3)
O8—C8—O7	124.3 (3)	C8—O7—H7O	109.5
O8—C8—C7	123.9 (3)	C2—C3—H3	119.2
O7—C8—C7	111.9 (3)	C4—C3—H3	113.2
C2—C3—C4	127.5 (3)	C4—O4—H4	109.5
O6—C5—O5	124.3 (3)	C1—O2—H2	109.5
O6—C5—C6	123.3 (3)	C6—C7—H7	112.5
O5—C5—C6	112.4 (3)	C8—C7—H7	119.9
C7—C6—C5	120.8 (3)	C5—O5—H5	109.5

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O7—H7O···O1^i	0.82	1.89	2.702 (3)	168
O4—H4···O6^ii	0.82	1.93	2.752 (3)	175
O2—H2···O8^iii	0.82	1.81	2.621 (3)	169
O5—H5···O3^iv	0.82	1.76	2.574 (3)	170

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