1-Bromo-4-chloro-2,5-dimethoxy-benzene.

The mol-ecule of the title compound, C(8)H(8)BrClO(2), sits on a crystallographic inversion centre, which ensures that the halogen sites are disordered, with exactly 50% Br and 50% Cl at each halogen site. The inversion renders the two meth-oxy groups equivalent. These groups lie almost in the plane of the aromatic ring system, making dihedral angles of 8.8 (4)° to the ring.

Related literature

For the synthesis of PCBs and PCB metabolites using the Suzuki coupling reaction, see: Lehmler & Robertson (2001 ▶); Song et al. (2008 ▶). For similar structures of halogenated meth­oxy-benzenes, see: Rissanen et al. (1988 ▶); Telu et al. (2008 ▶) and literature cited therein. For general background about PCBs, see: Hansen (1999 ▶); Robertson & Hansen (2001 ▶).

Experimental

Crystal data

C8H8BrClO2

M = 251.50

Monoclinic,

a = 6.3804 (7) Å

b = 8.2586 (10) Å

c = 8.6337 (11) Å

β = 90.853 (6)°

V = 454.89 (9) Å3

Z = 2

Mo Kα radiation

μ = 4.77 mm−1

T = 90 K

0.25 × 0.22 × 0.22 mm

Data collection

Nonius KappaCCD diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T min = 0.310, T max = 0.350

1938 measured reflections

1021 independent reflections

824 reflections with I > 2σ(I)

R int = 0.032

Refinement

R[F 2 > 2σ(F 2)] = 0.030

wR(F 2) = 0.069

S = 1.04

1021 reflections

61 parameters

2 restraints

H-atom parameters constrained

Δρmax = 0.57 e Å−3

Δρmin = −0.49 e Å−3

Data collection: COLLECT (Nonius, 1998 ▶); cell refinement: SCALEPACK (Otwinowski & Minor, 1997 ▶); data reduction: DENZO-SMN (Otwinowski & Minor, 1997 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XP in SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELX97 and local procedures.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810000504/si2231sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810000504/si2231Isup2.hkl

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

C8H8BrClO2	F(000) = 248
Mr = 251.50	Dx = 1.836 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1051 reflections
a = 6.3804 (7) Å	θ = 1.0–27.5°
b = 8.2586 (10) Å	µ = 4.77 mm−1
c = 8.6337 (11) Å	T = 90 K
β = 90.853 (6)°	Block, colourless
V = 454.89 (9) Å3	0.25 × 0.22 × 0.22 mm
Z = 2

Nonius KappaCCD diffractometer	1021 independent reflections
Radiation source: fine-focus sealed tube	824 reflections with I > 2σ(I)
graphite	Rint = 0.032
Detector resolution: 18 pixels mm-1	θmax = 27.3°, θmin = 3.4°
ω scans at fixed χ = 55°	h = −8→8
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	k = −10→10
Tmin = 0.310, Tmax = 0.350	l = −11→11
1938 measured reflections

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.030	H-atom parameters constrained
wR(F2) = 0.069	w = 1/[σ2(Fo2) + (0.0274P)2 + 0.2316P] where P = (Fo2 + 2Fc2)/3
S = 1.04	(Δ/σ)max = 0.001
1021 reflections	Δρmax = 0.57 e Å−3
61 parameters	Δρmin = −0.49 e Å−3
2 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.010 (2)

Experimental. The crystals were of surprisingly poor quality, with diffraction spots around 3° wide. Nevertheless, because the cell is quite small there were no problems with reflection overlap.

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 > 2σ(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.The structure straddles an inversion centre but the molecule itself does not possess inversion point symmetry, thus it is forced to be disordered in the crystal. This disorder places Cl and Br atoms at 50% occupancy in essentially the same position. For refinement, the C—Cl distance was restrained to be 0.916 times that of the C—Br distance. The ratio used was taken from the International Tables volume C. Further, anisotropic displacement parameters for the Br and Cl atoms were made equal.

	x	y	z	Uiso*/Ueq	Occ. (<1)
Br1	0.7756 (12)	0.2627 (9)	0.7207 (9)	0.0235 (3)	0.50
Cl1	0.760 (3)	0.271 (2)	0.711 (2)	0.0235 (3)	0.50
O1	0.6036 (3)	0.5566 (2)	0.19443 (19)	0.0247 (4)
C1	0.6144 (4)	0.3987 (3)	0.5927 (3)	0.0212 (6)
C2	0.6749 (4)	0.4217 (3)	0.4409 (3)	0.0213 (6)
H2	0.7945	0.3673	0.4023	0.026*
C3	0.5597 (4)	0.5244 (3)	0.3457 (3)	0.0208 (6)
C4	0.7634 (4)	0.4604 (3)	0.1242 (3)	0.0281 (6)
H4A	0.8990	0.4839	0.1740	0.042*
H4B	0.7701	0.4861	0.0136	0.042*
H4C	0.7302	0.3454	0.1371	0.042*

	U11	U22	U33	U12	U13	U23
Br1	0.0261 (12)	0.0218 (8)	0.0226 (10)	0.0081 (6)	−0.0047 (6)	0.0023 (5)
Cl1	0.0261 (12)	0.0218 (8)	0.0226 (10)	0.0081 (6)	−0.0047 (6)	0.0023 (5)
O1	0.0299 (11)	0.0221 (10)	0.0222 (10)	0.0029 (8)	0.0045 (8)	0.0016 (7)
C1	0.0221 (14)	0.0181 (13)	0.0232 (14)	−0.0004 (10)	−0.0038 (10)	−0.0013 (10)
C2	0.0214 (14)	0.0165 (13)	0.0259 (14)	0.0000 (10)	0.0005 (10)	−0.0043 (10)
C3	0.0230 (14)	0.0162 (12)	0.0232 (13)	−0.0037 (10)	0.0012 (10)	−0.0016 (10)
C4	0.0278 (16)	0.0314 (15)	0.0254 (15)	0.0043 (12)	0.0069 (12)	−0.0011 (12)

Br1—C1	1.872 (4)	C2—C3	1.385 (3)
Cl1—C1	1.727 (9)	C2—H2	0.9500
O1—C3	1.366 (3)	C3—C1i	1.392 (3)
O1—C4	1.434 (3)	C4—H4A	0.9800
C1—C2	1.385 (3)	C4—H4B	0.9800
C1—C3i	1.392 (3)	C4—H4C	0.9800
C3—O1—C4	116.95 (19)	O1—C3—C2	124.9 (2)
C2—C1—C3i	122.3 (2)	O1—C3—C1i	116.9 (2)
C2—C1—Cl1	119.2 (8)	C2—C3—C1i	118.2 (2)
C3i—C1—Cl1	118.5 (8)	O1—C4—H4A	109.5
C2—C1—Br1	118.8 (3)	O1—C4—H4B	109.5
C3i—C1—Br1	118.9 (3)	H4A—C4—H4B	109.5
C3—C2—C1	119.5 (2)	O1—C4—H4C	109.5
C3—C2—H2	120.2	H4A—C4—H4C	109.5
C1—C2—H2	120.2	H4B—C4—H4C	109.5
C3i—C1—C2—C3	0.1 (4)	C4—O1—C3—C1i	−171.2 (2)
Cl1—C1—C2—C3	−179.7 (8)	C1—C2—C3—O1	−180.0 (2)
Br1—C1—C2—C3	−178.7 (3)	C1—C2—C3—C1i	−0.1 (4)
C4—O1—C3—C2	8.7 (4)