2,2'-Di­bromo-3,3',4,4',5,5',6,6'-octa­methyl-1,1'-bi­phenyl

The title compound, C₂₉H₂₄Br₂, has crystallographic twofold rotation symmetry. The Br atom in the 2 position is disordered with the methyl group in the 6 position. The bi­phenyl bridge bond distance and the torsion angle between the rings are in good agreement with similar previously reported structures.

Key indicators

• Single-crystal X-ray study
• T = 174 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.038
• wR factor = 0.050
• Data-to-parameter ratio = 10.5

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT027_ALERT_3_A _diffrn_reflns_theta_full (too) Low ............      24.69 Deg.

Author Response: Due to the disorder within the molecule, there was a rapid drop-off in intensity with increasing sin(theta/lambda). This resulted in few data being recorded at high angle, and hence the data were only integrated to 0.85A.

Alert level B
PLAT201_ALERT_2_B Isotropic non-H Atoms in Main Residue(s) .......          1

Alert level C
THETM01_ALERT_3_C  The value of sine(theta_max)/wavelength is less than 0.590
            Calculated sin(theta_max)/wavelength =    0.5877
PLAT023_ALERT_3_C Resolution (too) Low [sin(th)/Lambda < 0.6].....      24.69 Deg.
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT161_ALERT_4_C Missing or Zero su (esd) on x-coordinate for ...        C10
PLAT161_ALERT_4_C Missing or Zero su (esd) on x-coordinate for ...        C11
PLAT162_ALERT_4_C Missing or Zero su (esd) on y-coordinate for ...        C10
PLAT162_ALERT_4_C Missing or Zero su (esd) on y-coordinate for ...        C11
PLAT163_ALERT_4_C Missing or Zero su (esd) on z-coordinate for ...        C10
PLAT163_ALERT_4_C Missing or Zero su (esd) on z-coordinate for ...        C11
PLAT301_ALERT_3_C Main Residue  Disorder .........................      15.00 Perc.
PLAT366_ALERT_2_C Short? C(sp?)-C(sp?) Bond  C1     -   C2     ...       1.39 Ang.
PLAT431_ALERT_2_C Short Inter HL..A Contact  Br2    ..  Br2     ..       3.53 Ang.

   1 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
  12 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
   3 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
   6 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003; data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: TEXSAN (Molecular Structure Corporation & Rigaku, 1998); molecular graphics: TEXSAN; software used to prepare material for publication: TEXSAN.

(I)

Crystal data

C20H24Br2	F(000) = 856.00
Mr = 424.22	Dx = 1.591 Mg m^−3
Orthorhombic, Pbcn	Mo Kα radiation, λ = 0.7107 Å
Hall symbol: -P 2n 2ab	Cell parameters from 2260 reflections
a = 13.530 (4) Å	θ = 2.4–24.0°
b = 10.987 (4) Å	µ = 4.59 mm^−1
c = 11.916 (3) Å	T = 174 K
V = 1771.4 (9) Å^3	Block, colorless
Z = 4	0.29 × 0.21 × 0.13 mm

Data collection

Bruker SMART 1000 diffractometer	1061 reflections with I > 3σ(I)
ω scans	Rint = 0.046
Absorption correction: multi-scan (Blessing, 1995)	θmax = 24.7°
Tmin = 0.280, Tmax = 0.554	h = −13→15
7776 measured reflections	k = −12→12
1483 independent reflections	l = −13→13

Refinement

Refinement on F	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.038	w = 1/[σ^2(Fo) + 0.00022|Fo|^2]
wR(F^2) = 0.050	(Δ/σ)max = 0.0004
S = 1.85	Δρmax = 0.28 e Å^−3
1061 reflections	Δρmin = −0.35 e Å^−3
101 parameters

Special details

Refinement. Refinement using reflections with F² > 3.0 σ(F²). The weighted R-factor (wR), goodness of fit (S) and R-factor (gt) are based on F, with F set to zero for negative F. The threshold expression of F² > 3.0 σ(F²) is used only for calculating R-factor (gt).

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
Br1	0.51423 (5)	0.30856 (6)	0.58452 (5)	0.0328 (2)	0.73
Br2	0.5631 (2)	−0.0719 (2)	0.8885 (2)	0.0435 (7)	0.27
C1	0.5548 (3)	0.1223 (4)	0.7401 (3)	0.023 (1)
C2	0.5974 (3)	0.2037 (4)	0.6644 (4)	0.024 (1)
C3	0.6999 (3)	0.2099 (4)	0.6462 (4)	0.028 (1)
C4	0.7598 (3)	0.1318 (4)	0.7077 (4)	0.031 (1)
C5	0.7193 (4)	0.0475 (4)	0.7826 (4)	0.031 (2)
C6	0.6175 (3)	0.0418 (4)	0.7977 (4)	0.027 (1)
C7	0.7430 (4)	0.3007 (4)	0.5645 (4)	0.040 (2)
C8	0.8722 (4)	0.1364 (5)	0.6924 (5)	0.047 (2)
C9	0.7856 (4)	−0.0392 (5)	0.8466 (5)	0.050 (2)
C10	0.5712	−0.0551	0.8752	0.0456*	0.73
C11	0.5287	0.2909	0.5984	0.0456*	0.27
H1	0.7893	0.3511	0.6023	0.0477*
H2	0.7752	0.2585	0.5053	0.0477*
H3	0.6914	0.3496	0.5344	0.0477*
H4	0.8893	0.2055	0.6486	0.0567*
H5	0.8938	0.0646	0.6553	0.0567*
H6	0.9031	0.1420	0.7637	0.0567*
H7	0.8321	0.0061	0.8894	0.0600*
H8	0.7467	−0.0879	0.8953	0.0600*
H9	0.8198	−0.0900	0.7951	0.0600*
H10	0.5019	−0.0424	0.8796	0.0547*	0.73
H11	0.5840	−0.1338	0.8457	0.0547*	0.73
H12	0.5993	−0.0486	0.9480	0.0547*	0.73
H13	0.5533	0.3717	0.6038	0.0547*	0.27
H14	0.5268	0.2670	0.5218	0.0547*	0.27
H15	0.4640	0.2875	0.6290	0.0547*	0.27

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0289 (4)	0.0322 (4)	0.0374 (4)	0.0051 (3)	0.0004 (3)	0.0080 (3)
Br2	0.053 (2)	0.041 (1)	0.037 (1)	0.0124 (10)	0.0117 (9)	0.0174 (9)
C1	0.024 (2)	0.020 (3)	0.027 (3)	−0.001 (2)	0.004 (2)	−0.005 (2)
C2	0.023 (3)	0.021 (3)	0.028 (3)	0.001 (2)	0.001 (2)	−0.001 (2)
C3	0.027 (3)	0.029 (3)	0.030 (3)	−0.001 (2)	0.006 (2)	−0.008 (2)
C4	0.018 (3)	0.035 (3)	0.039 (3)	0.002 (2)	0.002 (2)	−0.014 (2)
C5	0.031 (3)	0.033 (3)	0.031 (3)	0.009 (2)	−0.003 (2)	−0.009 (2)
C6	0.031 (3)	0.026 (3)	0.025 (3)	0.005 (2)	0.002 (2)	−0.002 (2)
C7	0.034 (3)	0.038 (3)	0.047 (3)	−0.001 (2)	0.013 (2)	0.005 (3)
C8	0.027 (3)	0.051 (4)	0.064 (4)	0.003 (3)	0.003 (3)	−0.005 (3)
C9	0.044 (3)	0.049 (3)	0.057 (4)	0.023 (3)	−0.003 (3)	0.001 (3)

Geometric parameters (Å, º)

Br1—C2	1.871 (4)	C7—H2	0.950
Br2—C6	1.809 (5)	C7—H3	0.950
C1—C1^i	1.502 (9)	C8—H4	0.950
C1—C2	1.395 (6)	C8—H5	0.950
C1—C6	1.405 (6)	C8—H6	0.950
C2—C3	1.405 (6)	C9—H7	0.950
C2—C11	1.549 (4)	C9—H8	0.950
C3—C4	1.389 (6)	C9—H9	0.950
C3—C7	1.511 (6)	C10—H10	0.950
C4—C5	1.399 (7)	C10—H11	0.950
C4—C8	1.532 (6)	C10—H12	0.950
C5—C6	1.390 (6)	C11—H13	0.950
C5—C9	1.514 (6)	C11—H14	0.950
C6—C10	1.542 (4)	C11—H15	0.950
C7—H1	0.950
Br1···Br2^ii	3.557 (2)	Br2···Br2^iv	3.532 (4)
Br2···C11^iii	3.502 (2)
C1—C1^i—C2^i	120.7 (4)	H1—C7—H3	109.5
C1—C1^i—C6^i	121.3 (4)	H2—C7—H3	109.5
C2—C1—C6	118.0 (4)	C4—C8—H4	109.5
Br1—C2—C1	118.3 (3)	C4—C8—H5	109.5
Br1—C2—C3	119.1 (3)	C4—C8—H6	109.5
C1—C2—C3	122.6 (4)	H4—C8—H5	109.5
C1—C2—C11	118.5 (3)	H4—C8—H6	109.5
C3—C2—C11	118.9 (3)	H5—C8—H6	109.5
C2—C3—C4	117.7 (4)	C5—C9—H7	109.5
C2—C3—C7	120.8 (4)	C5—C9—H8	109.5
C4—C3—C7	121.5 (4)	C5—C9—H9	109.5
C3—C4—C5	121.1 (4)	H7—C9—H8	109.5
C3—C4—C8	119.7 (5)	H7—C9—H9	109.5
C5—C4—C8	119.1 (4)	H8—C9—H9	109.5
C4—C5—C6	120.0 (4)	C6—C10—H10	109.5
C4—C5—C9	120.4 (4)	C6—C10—H11	109.5
C6—C5—C9	119.6 (4)	C6—C10—H12	109.5
Br2—C6—C1	118.8 (3)	H10—C10—H11	109.5
Br2—C6—C5	120.7 (4)	H10—C10—H12	109.5
C1—C6—C5	120.5 (4)	H11—C10—H12	109.5
C1—C6—C10	118.8 (4)	C2—C11—H13	109.5
C5—C6—C10	120.7 (4)	C2—C11—H14	109.5
C3—C7—H1	109.5	C2—C11—H15	109.5
C3—C7—H2	109.5	H13—C11—H14	109.5
C3—C7—H3	109.5	H13—C11—H15	109.5
H1—C7—H2	109.5	H14—C11—H15	109.5
Br1—C2—C1—C1^i	−2.2 (6)	C2—C1—C6—C5	2.7 (6)
Br1—C2—C1—C6	178.5 (3)	C2—C1—C6—C10	−175.6 (3)
Br1—C2—C3—C4	179.3 (3)	C2—C3—C4—C5	1.8 (7)
Br1—C2—C3—C7	0.7 (6)	C2—C3—C4—C8	−179.0 (4)
Br2—C6—C1—C1^i	5.2 (6)	C3—C2—C1—C6	−1.7 (6)
Br2—C6—C1—C2	−175.5 (3)	C3—C4—C5—C6	−0.8 (7)
Br2—C6—C5—C4	176.7 (4)	C3—C4—C5—C9	178.4 (4)
Br2—C6—C5—C9	−2.5 (6)	C4—C3—C2—C11	179.1 (3)
C1—C1^i—C2^i—C3^i	177.6 (4)	C4—C5—C6—C10	176.7 (4)
C1—C1^i—C2^i—C11^i	−2.1 (6)	C5—C4—C3—C7	−179.6 (4)
C1—C1^i—C6^i—C5^i	−176.6 (4)	C6—C1—C1^i—C6^i	−85.1 (8)
C1—C1^i—C6^i—C10^i	5.1 (6)	C6—C1—C2—C11	178.6 (3)
C1—C2—C3—C4	−0.5 (7)	C6—C5—C4—C8	180.0 (4)
C1—C2—C3—C7	−179.2 (4)	C7—C3—C2—C11	0.5 (6)
C1—C6—C5—C4	−1.5 (7)	C7—C3—C4—C8	−0.4 (7)
C1—C6—C5—C9	179.3 (4)	C8—C4—C5—C9	−0.8 (7)
C2—C1—C1^i—C2^i	−83.7 (8)	C9—C5—C6—C10	−2.5 (6)
C2—C1—C1^i—C6^i	95.6 (3)

Symmetry codes: (i) −x+1, y, −z+3/2; (ii) x, −y, z−1/2; (iii) x, −y, z+1/2; (iv) −x+1, −y, −z+2.