2,2',6,6'-Tetra­bromo­biphen­yl

The title compound, C₁₂H₆Br₄, is isostructural with the corresponding Cl analogue. The mol­ecule lies on a twofold rotation axis which runs perpendicular to the central C-C bond and the dihedral angle between the benzene rings is 85.2 (2)°.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.013 Å
• R factor = 0.048
• wR factor = 0.127
• Data-to-parameter ratio = 15.8

checkCIF/PLATON results

No syntax errors found



Alert level A
ABSTM02_ALERT_3_A  Crystal and compound unsuitable for non-numerical
               corrections. Product of mu and tmid > 3.0
             Value of mu given =    12.071 tmid =     0.400

Author Response: The title compound is a poor diffracting sample and no well-shaped single crystals were available for data collection. Data were collected using a rather large irregular block and absorption correction was applied on the basis of \D-F (DIFABS).

PLAT061_ALERT_3_A Tmax/Tmin Range Test RR' too Large .............       0.35

Author Response: The title compound is a poor diffracting sample and no well-shaped single crystals were available for data collection. Data were collected using a rather large irregular block and absorption correction was applied on the basis of \D-F (DIFABS).

PLAT065_ALERT_3_A Crystal Requires Numerical Correction mu*tmid ..       4.83

Author Response: The title compound is a poor diffracting sample and no well-shaped single crystals were available for data collection. Data were collected using a rather large irregular block and absorption correction was applied on the basis of \D-F (DIFABS).

Alert level C
PLAT341_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...         13

   3 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   4 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: XSCANS (Siemens, 1996); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXTL-Plus (Sheldrick, 1998); program(s) used to refine structure: SHELXTL-Plus; molecular graphics: SHELXTL-Plus; software used to prepare material for publication: SHELXTL-Plus.

2,6,2',6'-Tetrabromobiphenyl

Crystal data

C12H6Br4	Dx = 2.346 Mg m^−3
Mr = 469.81	Melting point = 487–489 K
Orthorhombic, Pbcn	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2n 2ab	Cell parameters from 64 reflections
a = 10.615 (3) Å	θ = 4.8–11.8°
b = 9.8137 (18) Å	µ = 12.07 mm^−1
c = 12.768 (3) Å	T = 298 K
V = 1330.2 (5) Å^3	Irregular fragment, colourless
Z = 4	0.4 × 0.4 × 0.3 mm
F(000) = 872

Data collection

Bruker P4 diffractometer	729 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube, FN4	Rint = 0.053
Graphite monochromator	θmax = 25.0°, θmin = 2.8°
ω/2θ scans	h = −12→12
Absorption correction: part of the refinement model (ΔF) DIFABS in WinGX (Walker & Stuart, 1983; Farrugia, 1999)	k = −11→8
Tmin = 0.004, Tmax = 0.027	l = −15→15
2756 measured reflections	3 standard reflections every 97 reflections
1168 independent reflections	intensity decay: 7%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.048	H-atom parameters constrained
wR(F^2) = 0.127	w = 1/[σ^2(Fo^2) + (0.0433P)^2 + 5.0627P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max < 0.001
1168 reflections	Δρmax = 0.65 e Å^−3
74 parameters	Δρmin = −0.45 e Å^−3
0 restraints	Extinction correction: SHELXTL-Plus (Sheldrick, 1998), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0024 (5)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Br1	0.49817 (10)	0.84213 (9)	0.07626 (7)	0.0717 (4)
Br2	0.61036 (13)	0.45561 (12)	0.39293 (9)	0.0962 (5)
C1	0.5686 (8)	0.6535 (7)	0.2345 (6)	0.052 (2)
C2	0.6120 (9)	0.7357 (8)	0.1542 (6)	0.055 (2)
C3	0.7379 (10)	0.7435 (9)	0.1270 (7)	0.065 (3)
H3B	0.7640	0.8006	0.0731	0.078*
C4	0.8239 (10)	0.6658 (10)	0.1806 (8)	0.079 (3)
H4B	0.9091	0.6717	0.1643	0.095*
C5	0.7842 (10)	0.5794 (10)	0.2582 (7)	0.073 (3)
H5B	0.8420	0.5243	0.2929	0.088*
C6	0.6596 (10)	0.5744 (9)	0.2846 (7)	0.063 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0692 (7)	0.0746 (7)	0.0713 (6)	0.0143 (6)	−0.0011 (6)	0.0129 (5)
Br2	0.1017 (10)	0.0964 (8)	0.0904 (8)	0.0241 (7)	0.0159 (7)	0.0373 (6)
C1	0.052 (5)	0.051 (4)	0.053 (5)	0.003 (4)	−0.002 (4)	−0.004 (4)
C2	0.047 (6)	0.064 (5)	0.053 (4)	0.004 (5)	0.008 (4)	−0.003 (4)
C3	0.059 (7)	0.066 (6)	0.070 (5)	0.000 (5)	0.011 (5)	0.006 (5)
C4	0.046 (6)	0.098 (8)	0.092 (7)	0.014 (6)	0.003 (6)	−0.003 (6)
C5	0.055 (7)	0.089 (7)	0.075 (6)	0.032 (6)	0.007 (6)	0.015 (5)
C6	0.067 (7)	0.060 (5)	0.063 (5)	0.012 (5)	0.008 (5)	0.002 (4)

Geometric parameters (Å, º)

Br1—C2	1.882 (9)	C3—C4	1.372 (13)
Br2—C6	1.883 (9)	C3—H3B	0.9300
C1—C2	1.383 (11)	C4—C5	1.370 (13)
C1—C6	1.394 (12)	C4—H4B	0.9300
C1—C1^i	1.509 (17)	C5—C6	1.366 (14)
C2—C3	1.383 (13)	C5—H5B	0.9300
C2—C1—C6	115.7 (8)	C5—C4—C3	120.0 (10)
C2—C1—C1^i	121.1 (8)	C5—C4—H4B	120.0
C6—C1—C1^i	123.2 (8)	C3—C4—H4B	120.0
C1—C2—C3	122.7 (8)	C6—C5—C4	119.9 (9)
C1—C2—Br1	120.1 (7)	C6—C5—H5B	120.0
C3—C2—Br1	117.2 (7)	C4—C5—H5B	120.0
C4—C3—C2	119.1 (9)	C5—C6—C1	122.5 (9)
C4—C3—H3B	120.4	C5—C6—Br2	118.2 (7)
C2—C3—H3B	120.4	C1—C6—Br2	119.3 (7)
C6—C1—C2—C3	−2.2 (12)	C3—C4—C5—C6	−2.3 (15)
C1^i—C1—C2—C3	176.7 (8)	C4—C5—C6—C1	0.8 (16)
C6—C1—C2—Br1	177.4 (6)	C4—C5—C6—Br2	−179.2 (7)
C1^i—C1—C2—Br1	−3.7 (10)	C2—C1—C6—C5	1.4 (13)
C1—C2—C3—C4	0.7 (14)	C1^i—C1—C6—C5	−177.4 (9)
Br1—C2—C3—C4	−178.9 (7)	C2—C1—C6—Br2	−178.6 (6)
C2—C3—C4—C5	1.6 (14)	C1^i—C1—C6—Br2	2.6 (11)

Symmetry code: (i) −x+1, y, −z+1/2.