2-(Dibromo­meth­yl)benzoic acid

Abstract

In the crystal structure of the title compound, C₈H₆Br₂O₂, the carboxyl groups are involved in pairs of O—H⋯O hydrogen bonds, which link the mol­ecules into inversion dimers.

Related literature

For the preparation of the title compound, see: Eliel & Rivard (1952 ▶). For its applications, see: Dey & Mal (2005 ▶). For graph-set theory, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

• C₈H₆Br₂O₂

• M _r = 293.95

• Monoclinic,

• a = 4.9988 (6) Å

• b = 25.617 (3) Å

• c = 7.1844 (8) Å

• β = 97.709 (10)°

• V = 911.68 (18) ų

• Z = 4

• Mo Kα radiation

• μ = 8.85 mm⁻¹

• T = 297 K

• 0.74 × 0.36 × 0.25 mm

Data collection

• Bruker SMART CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T _min = 0.251, T _max = 1.000

• 7515 measured reflections

• 2210 independent reflections

• 1221 reflections with I > 2σ(I)

• R _int = 0.088

Refinement

• R[F ² > 2σ(F ²)] = 0.091

• wR(F ²) = 0.227

• S = 1.13

• 2210 reflections

• 109 parameters

• H-atom parameters constrained

• Δρ_max = 0.85 e Å⁻³

• Δρ_min = −0.93 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2001 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Supplementary material file. DOI: 10.1107/S1600536811052858/lx2208Isup3.cml

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2A⋯O1i	0.82	1.82	2.641 (11)	176

Symmetry code: (i) .

supplementary crystallographic information

Comment

The title compound is a useful reagent to prepare phthalaldehydic acid (Eliel & Rivard, 1952). In addition, it has been prepared as a potential precursor to an antitumour agent, BE-23254. (Dey & Mal, 2005). The structure of the title compound is shown in Fig. 1. In the crystal structure (Fig. 2), inversion-related molecules are linked by pairs of O–H···O hydrogen bonds, forming a cyclic dimers with R₂²(8) graph-set motif (Table 1) (Bernstein et al., 1995). The intramolecular C–H···O hydrogen bond (Table 1) generates an S(6) ring motif .

Experimental

The title compound was synthesized according to the literature (Eliel & Rivard, 1952). Single crystals suitable for X-ray diffraction were prepared by slow evaporation of a solution of the title compound in chloroform at room temperature for six weeks.

Refinement

The C bound H atoms positioned geometrically (C–H = 0.93-0.98 Å) and allowed to ride on their parent atoms, with U_iso(H) = 1.2U_eq(C)]. The O bound H atoms positioned geometrically (O–H = 0.82 Å) and allowed to ride on their parent atoms, with U_iso(H) =1.5U_eq(O)].

Figures

Fig. 1.

The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are presented as small spheres of arbitrary radius.

Fig. 2.

A view of the O–H···O hydrogen bonds (dotted lines) in the crystal structure of the title compound.

Crystal data

C8H6Br2O2	F(000) = 560
Mr = 293.95	Dx = 2.142 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 2762 reflections
a = 4.9988 (6) Å	θ = 2.9–29.2°
b = 25.617 (3) Å	µ = 8.85 mm−1
c = 7.1844 (8) Å	T = 297 K
β = 97.709 (10)°	Parallelepiped, colorless
V = 911.68 (18) Å3	0.74 × 0.36 × 0.25 mm
Z = 4

Data collection

Bruker SMART CCD area-detector diffractometer	2210 independent reflections
Radiation source: fine-focus sealed tube	1221 reflections with I > 2σ(I)
graphite	Rint = 0.088
ω scans	θmax = 29.3°, θmin = 3.0°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −6→6
Tmin = 0.251, Tmax = 1.000	k = −34→34
7515 measured reflections	l = −9→9

Refinement

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)] = 0.091	Hydrogen site location: difference Fourier map
wR(F2) = 0.227	H-atom parameters constrained
S = 1.13	w = 1/[σ2(Fo2) + (0.0876P)2 + 4.8672P] where P = (Fo2 + 2Fc2)/3
2210 reflections	(Δ/σ)max = 0.001
109 parameters	Δρmax = 0.85 e Å−3
0 restraints	Δρmin = −0.93 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
Br1	0.4317 (3)	0.14770 (6)	0.73655 (16)	0.0676 (5)
Br2	0.6793 (3)	0.22661 (4)	0.4627 (2)	0.0700 (5)
O1	0.8610 (16)	0.0565 (3)	0.5279 (11)	0.055 (2)
O2	0.7203 (17)	−0.0025 (3)	0.3117 (11)	0.057 (2)
H2A	0.8523	−0.0181	0.3649	0.086*
C1	0.613 (2)	0.1540 (4)	0.5132 (14)	0.038 (2)
H1A	0.7859	0.1356	0.5355	0.046*
C2	0.4355 (19)	0.1276 (3)	0.3520 (12)	0.032 (2)
C3	0.216 (2)	0.1550 (4)	0.2570 (14)	0.043 (2)
H3A	0.1840	0.1890	0.2926	0.052*
C4	0.050 (2)	0.1329 (4)	0.1143 (14)	0.045 (3)
H4A	−0.0943	0.1519	0.0528	0.054*
C5	0.093 (2)	0.0821 (4)	0.0596 (14)	0.050 (3)
H5A	−0.0223	0.0667	−0.0375	0.060*
C6	0.307 (2)	0.0547 (4)	0.1501 (14)	0.041 (2)
H6A	0.3367	0.0207	0.1115	0.049*
C7	0.484 (2)	0.0759 (4)	0.2988 (12)	0.033 (2)
C8	0.702 (2)	0.0430 (4)	0.3896 (14)	0.037 (2)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Br1	0.0750 (9)	0.0939 (10)	0.0320 (6)	0.0025 (8)	0.0000 (5)	−0.0081 (6)
Br2	0.0771 (10)	0.0335 (6)	0.0951 (11)	−0.0055 (6)	−0.0039 (8)	−0.0100 (6)
O1	0.060 (5)	0.039 (4)	0.062 (5)	0.013 (4)	−0.013 (4)	−0.011 (4)
O2	0.065 (5)	0.036 (4)	0.065 (5)	0.011 (4)	−0.011 (4)	−0.011 (4)
C1	0.043 (6)	0.028 (5)	0.042 (6)	0.007 (4)	0.003 (5)	−0.010 (4)
C2	0.040 (5)	0.030 (4)	0.024 (4)	0.002 (4)	−0.002 (4)	0.000 (4)
C3	0.056 (7)	0.037 (5)	0.037 (6)	0.004 (5)	0.010 (5)	0.000 (4)
C4	0.039 (6)	0.062 (7)	0.032 (5)	−0.003 (5)	0.000 (4)	0.009 (5)
C5	0.057 (7)	0.060 (7)	0.029 (5)	−0.013 (6)	−0.009 (5)	−0.004 (5)
C6	0.034 (5)	0.045 (6)	0.043 (6)	−0.001 (5)	0.002 (4)	−0.013 (5)
C7	0.044 (6)	0.034 (5)	0.022 (4)	0.000 (4)	0.004 (4)	0.001 (4)
C8	0.042 (6)	0.031 (5)	0.040 (6)	−0.002 (4)	0.016 (5)	−0.001 (4)

Geometric parameters (Å, °)

Br1—C1	1.951 (10)	C3—C4	1.354 (14)
Br2—C1	1.932 (10)	C3—H3A	0.9300
O1—C8	1.235 (12)	C4—C5	1.386 (15)
O2—C8	1.302 (11)	C4—H4A	0.9300
O2—H2A	0.8200	C5—C6	1.370 (15)
C1—C2	1.519 (13)	C5—H5A	0.9300
C1—H1A	0.9800	C6—C7	1.402 (13)
C2—C3	1.399 (14)	C6—H6A	0.9300
C2—C7	1.409 (12)	C7—C8	1.461 (14)
C8—O2—H2A	109.5	C3—C4—H4A	119.9
C2—C1—Br2	112.5 (7)	C5—C4—H4A	119.9
C2—C1—Br1	107.6 (7)	C6—C5—C4	119.3 (9)
Br2—C1—Br1	110.2 (4)	C6—C5—H5A	120.4
C2—C1—H1A	108.8	C4—C5—H5A	120.4
Br2—C1—H1A	108.8	C5—C6—C7	122.4 (9)
Br1—C1—H1A	108.8	C5—C6—H6A	118.8
C3—C2—C7	119.4 (9)	C7—C6—H6A	118.8
C3—C2—C1	119.2 (8)	C2—C7—C6	117.3 (9)
C7—C2—C1	121.4 (8)	C2—C7—C8	124.5 (9)
C4—C3—C2	121.5 (10)	C6—C7—C8	118.2 (9)
C4—C3—H3A	119.2	O1—C8—O2	121.5 (9)
C2—C3—H3A	119.2	O1—C8—C7	123.9 (9)
C3—C4—C5	120.2 (10)	O2—C8—C7	114.6 (9)
Br2—C1—C2—C3	−40.2 (11)	C1—C2—C7—C6	179.1 (9)
Br1—C1—C2—C3	81.4 (9)	C3—C2—C7—C8	−178.5 (9)
Br2—C1—C2—C7	141.2 (8)	C1—C2—C7—C8	0.1 (15)
Br1—C1—C2—C7	−97.3 (9)	C5—C6—C7—C2	−0.8 (15)
C7—C2—C3—C4	−0.2 (15)	C5—C6—C7—C8	178.3 (10)
C1—C2—C3—C4	−178.9 (9)	C2—C7—C8—O1	2.9 (16)
C2—C3—C4—C5	0.4 (16)	C6—C7—C8—O1	−176.1 (10)
C3—C4—C5—C6	−0.7 (16)	C2—C7—C8—O2	−176.3 (9)
C4—C5—C6—C7	0.9 (17)	C6—C7—C8—O2	4.7 (13)
C3—C2—C7—C6	0.4 (14)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2A···O1i	0.82	1.82	2.641 (11)	176
C1—H1A···O1	0.98	2.06	2.784 (13)	129

Symmetry codes: (i) −x+2, −y, −z+1.