trans,trans,trans-1,4-Dimeth­oxy-2,3,5,8-tetra­bromo­tetra­lin

The title compound, C₁₂H₁₂Br₄O₂, is a derivative of 1,2,3,4-tetra­hydro­naphthalene (tetra­lin), with 1,4-dimeth­oxy and 2,3-dibromo substituents on the saturated ring and 5,8-dibromo substituents on the aromatic ring. The mol­ecule occupies a special position on a twofold axis and the saturated ring has a half-chair conformation.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.018 Å
• R factor = 0.070
• wR factor = 0.150
• Data-to-parameter ratio = 19.6

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT341_ALERT_3_B Low Bond Precision on C-C bonds (x 1000) Ang ...         18

Alert level C
RINTA01_ALERT_3_C  The value of Rint is greater than 0.10
            Rint given   0.142
PLAT020_ALERT_3_C The value of Rint is greater than 0.10 .........       0.14
PLAT026_ALERT_3_C Ratio Observed / Unique Reflections too Low ....         49 Perc.
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.98
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.23
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          1
              C12 H12 Br4 O2

   0 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   6 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
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   5 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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Computing details

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

trans,trans,trans-1,4-Dimethoxy-2,3,5,8-tetrabromo-1,2,3,4-tetrahydronaphthalene

Crystal data

C12H12Br4O2	F(000) = 960
Mr = 507.82	Dx = 2.256 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 4073 reflections
a = 17.546 (5) Å	θ = 2.1–24.3°
b = 12.522 (5) Å	µ = 10.76 mm^−1
c = 7.405 (5) Å	T = 296 K
β = 113.207 (5)°	Prism, colourless
V = 1495.3 (12) Å^3	0.28 × 0.23 × 0.16 mm
Z = 4

Data collection

Stoe IPDS II diffractometer	1611 independent reflections
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus	797 reflections with I > 2σ(I)
Plane graphite monochromator	Rint = 0.142
Detector resolution: 6.67 pixels mm^-1	θmax = 27.1°, θmin = 2.1°
ω scans	h = −22→22
Absorption correction: integration (X-RED32; Stoe & Cie, 2002)	k = −16→15
Tmin = 0.084, Tmax = 0.203	l = −9→9
6748 measured 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)] = 0.070	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.150	H-atom parameters constrained
S = 1.01	w = 1/[σ^2(Fo^2) + (0.0498P)^2 + 0.9739P] where P = (Fo^2 + 2Fc^2)/3
1611 reflections	(Δ/σ)max = 0.001
82 parameters	Δρmax = 0.70 e Å^−3
0 restraints	Δρmin = −0.77 e Å^−3

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

Refinement. Refinement on F² for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The observed criterion of F² > σ(F²) is used only for calculating -R-factor-obs 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	0.19717 (12)	1.04368 (15)	0.3341 (2)	0.1433 (8)
Br2	0.07083 (7)	1.36218 (9)	0.58829 (16)	0.0740 (4)
O1	0.1061 (4)	1.2535 (6)	0.1056 (9)	0.072 (3)
C1	0.0435 (10)	0.9536 (10)	0.268 (2)	0.127 (8)
C2	0.0824 (9)	1.0510 (10)	0.2830 (14)	0.095 (5)
C3	0.0427 (6)	1.1449 (7)	0.2669 (12)	0.061 (3)
C4	0.0898 (6)	1.2484 (7)	0.2789 (13)	0.054 (3)
C5	0.0468 (6)	1.3467 (7)	0.3054 (13)	0.057 (3)
C6	0.1765 (7)	1.3157 (13)	0.128 (2)	0.113 (6)
H1	0.07250	0.88990	0.28020	0.1530*
H4	0.14310	1.24310	0.39150	0.0650*
H5	0.06960	1.40860	0.26290	0.0680*
H6A	0.18360	1.31740	0.00600	0.1700*
H6B	0.22480	1.28470	0.22810	0.1700*
H6C	0.16900	1.38700	0.16540	0.1700*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.1554 (15)	0.1830 (17)	0.0819 (9)	0.1213 (14)	0.0366 (9)	0.0053 (9)
Br2	0.0845 (8)	0.0729 (7)	0.0622 (6)	0.0003 (6)	0.0265 (5)	−0.0178 (6)
O1	0.073 (5)	0.093 (5)	0.057 (4)	−0.004 (4)	0.033 (4)	−0.018 (4)
C1	0.25 (2)	0.068 (8)	0.059 (7)	0.068 (10)	0.057 (15)	0.019 (7)
C2	0.159 (13)	0.069 (8)	0.045 (6)	0.047 (8)	0.026 (7)	0.009 (5)
C3	0.084 (6)	0.056 (5)	0.043 (5)	0.015 (5)	0.024 (5)	0.004 (5)
C4	0.047 (5)	0.047 (5)	0.057 (5)	0.003 (4)	0.009 (4)	−0.006 (4)
C5	0.072 (6)	0.041 (5)	0.060 (5)	0.004 (4)	0.028 (5)	0.000 (4)
C6	0.065 (7)	0.186 (14)	0.111 (10)	−0.042 (9)	0.059 (7)	−0.032 (10)

Geometric parameters (Å, º)

Br1—C2	1.899 (16)	C4—C5	1.497 (14)
Br2—C5	1.977 (9)	C5—C5^i	1.519 (15)
O1—C4	1.422 (12)	C1—H1	0.9312
O1—C6	1.414 (16)	C4—H4	0.9796
C1—C2	1.381 (19)	C5—H5	0.9793
C1—C1^i	1.44 (3)	C6—H6A	0.9596
C2—C3	1.348 (16)	C6—H6B	0.9609
C3—C4	1.521 (13)	C6—H6C	0.9591
C3—C3^i	1.419 (16)
Br1···O1	3.192 (8)	C6···Br2^vii	3.730 (14)
Br1···C6	3.692 (16)	C6···Br1^viii	3.557 (16)
Br1···Br1^ii	3.861 (3)	C5···H6C	2.7710
Br1···C6^iii	3.557 (16)	C6···H5	2.7103
Br1···Br1^iv	3.861 (3)	H1···O1^ii	2.8738
Br2···C6^v	3.730 (14)	H4···Br1	2.7630
Br2···O1^i	3.168 (8)	H4···H6B	2.2710
Br1···H6C^iii	3.0588	H5···C6	2.7103
Br1···H4	2.7630	H5···H6C	2.1514
Br1···H6B	3.2031	H5···Br2^ix	3.1516
Br2···H6A^v	2.9956	H6A···Br2^vii	2.9956
Br2···H5^vi	3.1516	H6B···Br1	3.2031
O1···Br1	3.192 (8)	H6B···H4	2.2710
O1···Br2^i	3.168 (8)	H6C···C5	2.7710
O1···H1^iv	2.8738	H6C···H5	2.1514
C6···Br1	3.692 (16)	H6C···Br1^viii	3.0588
C4—O1—C6	113.3 (8)	C2—C1—H1	121.00
C1^i—C1—C2	117.9 (13)	C1^i—C1—H1	121.06
Br1—C2—C1	115.2 (11)	O1—C4—H4	107.89
Br1—C2—C3	122.0 (10)	C3—C4—H4	107.85
C1—C2—C3	122.8 (15)	C5—C4—H4	107.80
C2—C3—C4	119.2 (11)	Br2—C5—H5	108.63
C2—C3—C3^i	119.3 (10)	C4—C5—H5	108.54
C3^i—C3—C4	121.5 (8)	C5^i—C5—H5	108.54
O1—C4—C3	106.5 (7)	O1—C6—H6A	109.47
O1—C4—C5	111.9 (7)	O1—C6—H6B	109.40
C3—C4—C5	114.7 (9)	O1—C6—H6C	109.50
Br2—C5—C4	108.2 (6)	H6A—C6—H6B	109.45
Br2—C5—C5^i	107.8 (7)	H6A—C6—H6C	109.55
C4—C5—C5^i	115.0 (8)	H6B—C6—H6C	109.45
C6—O1—C4—C3	−154.3 (9)	C3^i—C3—C4—C5	15.3 (12)
C6—O1—C4—C5	79.6 (11)	C2—C3—C3^i—C4^i	177.8 (8)
C1^i—C1—C2—C3	0.5 (18)	C4—C3—C3^i—C2^i	177.8 (8)
C1^i—C1—C2—Br1	179.2 (10)	C4—C3—C3^i—C4^i	−4.2 (12)
C2—C1—C1^i—C2^i	−0.7 (19)	O1—C4—C5—C5^i	84.2 (10)
Br1—C2—C3—C3^i	−178.6 (6)	C3—C4—C5—Br2	83.3 (8)
Br1—C2—C3—C4	3.4 (12)	C3—C4—C5—C5^i	−37.3 (11)
C1—C2—C3—C4	−178.1 (10)	O1—C4—C5—Br2	−155.3 (7)
C1—C2—C3—C3^i	0.0 (15)	C4—C5—C5^i—C4^i	49.7 (11)
C2—C3—C3^i—C2^i	−0.3 (13)	Br2—C5—C5^i—C4^i	−71.1 (8)
C2—C3—C4—O1	69.0 (10)	C4—C5—C5^i—Br2^i	−71.1 (8)
C2—C3—C4—C5	−166.7 (8)	Br2—C5—C5^i—Br2^i	168.2 (4)
C3^i—C3—C4—O1	−109.0 (9)

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