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In the title compound, C8H8Br2, the bond lengths and angles are in the normal range. All non-H atoms are coplanar.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807042602/bx2106sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536807042602/bx2106Isup2.hkl
Contains datablock I

CCDC reference: 663698

Key indicators

  • Single-crystal X-ray study
  • T = 298 K
  • Mean [sigma](C-C) = 0.007 Å
  • R factor = 0.036
  • wR factor = 0.097
  • Data-to-parameter ratio = 18.7

checkCIF/PLATON results

No syntax errors found



Alert level C PLAT062_ALERT_4_C Rescale T(min) & T(max) by ..................... 0.87 PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density .... 2.02 PLAT341_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ... 7 PLAT380_ALERT_4_C Check Incorrectly? Oriented X(sp2)-Methyl Moiety C8
Alert level G ABSTM02_ALERT_3_G When printed, the submitted absorption T values will be replaced by the scaled T values. Since the ratio of scaled T's is identical to the ratio of reported T values, the scaling does not imply a change to the absorption corrections used in the study. Ratio of Tmax expected/reported 0.870 Tmax scaled 0.403 Tmin scaled 0.230
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 4 ALERT level C = Check and explain 1 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 2 ALERT type 3 Indicator that the structure quality may be low 2 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check

Comment top

Molecules which possess novel belt-like and cage-like structures have played a central role in the development of supramolecular chemistry (Stoddart, 1989). Since maleimide derivatives are used frequently as the dienophiles in Diels-Alder cycloadditions, we are investigating methods of incorporating the maleimide moiety into 2-amino-1,2,3-triazolequinone derivatives. Considering the strategy synthetic in where the compound (I) it is used like precursor, we report here the structrure of (I), Fig.1.

Related literature top

The structures of the related compounds 1,2-dibromo-4,5-dimethyl-3-nitrobenzene and 1,2-dibromo-4,5,6-trimethyl-3-nitrobenzene have been reported by Skakle et al. (2006).

For related literature, see: Allen et al. (1987); Lawson et al. (1968); Stoddart (1989).

Experimental top

The title compound was synthesized according to a method described previously (Lawson et al., 1968). The reaction solution was diluted with diethyl ether and washed with brine. The organic solution was dried over MgSO4 and the solvent removed. Recrystallization in MeOH to give product as white crystals. 1H-NMR (300 MHz, CDCl3): (p.p.m.) = 7.35 (s, 2H), 2.17 (s, 6H). Analysis calculated for C8H8Br2: C 36.40, H 3.05; found (%): C 35.92, H 3.38.

Refinement top

The structure was solved by direct methods. All H atoms were placed at geometrically idealized positions and were treated as riding atoms, with C—H = 0.93 Å (aromatic) or 0.96 Å (methyl), and Uiso(H) = 1.2Ueq for aromatic and 1.5Ueq for methyl H atoms.

Structure description top

Molecules which possess novel belt-like and cage-like structures have played a central role in the development of supramolecular chemistry (Stoddart, 1989). Since maleimide derivatives are used frequently as the dienophiles in Diels-Alder cycloadditions, we are investigating methods of incorporating the maleimide moiety into 2-amino-1,2,3-triazolequinone derivatives. Considering the strategy synthetic in where the compound (I) it is used like precursor, we report here the structrure of (I), Fig.1.

The structures of the related compounds 1,2-dibromo-4,5-dimethyl-3-nitrobenzene and 1,2-dibromo-4,5,6-trimethyl-3-nitrobenzene have been reported by Skakle et al. (2006).

For related literature, see: Allen et al. (1987); Lawson et al. (1968); Stoddart (1989).

Computing details top

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1994); data reduction: XPREP (Siemens, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Sheldrick, 2000); software used to prepare material for publication: SHELXTL.

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound. Displacement ellipsoids are drawn at the 30% probability level.
1,2-Dibromo-4,5-dimethylbenzene top
Crystal data top
C8H8Br2F(000) = 504
Mr = 263.96Dx = 1.980 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P2ynCell parameters from 1764 reflections
a = 9.383 (4) Åθ = 2.4–25.1°
b = 7.918 (3) ŵ = 9.08 mm1
c = 12.612 (5) ÅT = 298 K
β = 109.041 (6)°Block, white
V = 885.7 (6) Å30.20 × 0.12 × 0.10 mm
Z = 4
Data collection top
Bruker SMART CCD
diffractometer
1735 independent reflections
Radiation source: fine-focus sealed tube1346 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.024
ω scansθmax = 26.0°, θmin = 2.4°
Absorption correction: empirical (using intensity measurements)
(SADABS; Sheldrick, 1996)
h = 811
Tmin = 0.264, Tmax = 0.464k = 79
4542 measured reflectionsl = 1515
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.036Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.097H-atom parameters constrained
S = 1.07 w = 1/[σ2(Fo2) + (0.0481P)2 + 0.5399P]
where P = (Fo2 + 2Fc2)/3
1735 reflections(Δ/σ)max = 0.001
93 parametersΔρmax = 0.69 e Å3
0 restraintsΔρmin = 0.34 e Å3
Crystal data top
C8H8Br2V = 885.7 (6) Å3
Mr = 263.96Z = 4
Monoclinic, P21/nMo Kα radiation
a = 9.383 (4) ŵ = 9.08 mm1
b = 7.918 (3) ÅT = 298 K
c = 12.612 (5) Å0.20 × 0.12 × 0.10 mm
β = 109.041 (6)°
Data collection top
Bruker SMART CCD
diffractometer
1735 independent reflections
Absorption correction: empirical (using intensity measurements)
(SADABS; Sheldrick, 1996)
1346 reflections with I > 2σ(I)
Tmin = 0.264, Tmax = 0.464Rint = 0.024
4542 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0360 restraints
wR(F2) = 0.097H-atom parameters constrained
S = 1.07Δρmax = 0.69 e Å3
1735 reflectionsΔρmin = 0.34 e Å3
93 parameters
Special details top

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 (Å2) top
xyzUiso*/Ueq
Br10.20495 (5)0.21958 (7)0.68821 (4)0.0680 (2)
Br20.06751 (6)0.44884 (7)0.87503 (4)0.0710 (2)
C30.2076 (5)0.4319 (5)0.7077 (4)0.0524 (11)
H30.28170.49610.75880.063*
C10.0297 (4)0.2898 (5)0.6581 (3)0.0445 (9)
C20.0831 (5)0.3833 (5)0.7341 (3)0.0460 (9)
C50.1127 (5)0.2935 (5)0.5291 (4)0.0473 (10)
C40.2257 (5)0.3871 (5)0.6057 (4)0.0513 (10)
C60.0124 (5)0.2452 (5)0.5561 (3)0.0481 (10)
H60.08700.18140.50510.058*
C80.3680 (6)0.4447 (6)0.5815 (5)0.0670 (13)
H8A0.34000.51490.51590.101*
H8B0.42190.34760.56910.101*
H8C0.43120.50750.64440.101*
C70.1231 (6)0.2415 (6)0.4139 (4)0.0561 (11)
H7A0.20900.16950.42460.084*
H7B0.13360.34060.37320.084*
H7C0.03320.18190.37210.084*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0524 (3)0.0926 (4)0.0663 (3)0.0102 (2)0.0294 (2)0.0049 (3)
Br20.0788 (4)0.0802 (4)0.0534 (3)0.0011 (3)0.0206 (3)0.0182 (2)
C30.043 (2)0.044 (2)0.063 (3)0.0005 (18)0.008 (2)0.0017 (19)
C10.041 (2)0.047 (2)0.048 (2)0.0053 (17)0.0171 (18)0.0016 (17)
C20.046 (2)0.045 (2)0.044 (2)0.0071 (18)0.0109 (18)0.0016 (17)
C50.051 (2)0.043 (2)0.051 (2)0.0062 (19)0.0201 (19)0.0062 (18)
C40.043 (2)0.043 (2)0.072 (3)0.0071 (18)0.025 (2)0.010 (2)
C60.047 (2)0.051 (2)0.046 (2)0.0028 (18)0.0147 (19)0.0035 (17)
C80.055 (3)0.062 (3)0.095 (4)0.006 (2)0.040 (3)0.013 (3)
C70.064 (3)0.068 (3)0.048 (2)0.006 (2)0.034 (2)0.008 (2)
Geometric parameters (Å, º) top
Br1—C11.889 (4)C5—C71.544 (6)
Br2—C21.902 (4)C4—C81.532 (6)
C3—C21.371 (6)C6—H60.9300
C3—C41.398 (6)C8—H8A0.9600
C3—H30.9300C8—H8B0.9600
C1—C21.387 (6)C8—H8C0.9600
C1—C61.393 (6)C7—H7A0.9600
C5—C61.380 (6)C7—H7B0.9600
C5—C41.392 (6)C7—H7C0.9600
C2—C3—C4121.5 (4)C5—C6—C1121.5 (4)
C2—C3—H3119.3C5—C6—H6119.2
C4—C3—H3119.3C1—C6—H6119.2
C2—C1—C6118.8 (4)C4—C8—H8A109.5
C2—C1—Br1122.4 (3)C4—C8—H8B109.5
C6—C1—Br1118.8 (3)H8A—C8—H8B109.5
C3—C2—C1120.0 (4)C4—C8—H8C109.5
C3—C2—Br2118.8 (3)H8A—C8—H8C109.5
C1—C2—Br2121.2 (3)H8B—C8—H8C109.5
C6—C5—C4119.5 (4)C5—C7—H7A109.5
C6—C5—C7118.6 (4)C5—C7—H7B109.5
C4—C5—C7121.9 (4)H7A—C7—H7B109.5
C5—C4—C3118.7 (4)C5—C7—H7C109.5
C5—C4—C8122.4 (4)H7A—C7—H7C109.5
C3—C4—C8118.9 (4)H7B—C7—H7C109.5

Experimental details

Crystal data
Chemical formulaC8H8Br2
Mr263.96
Crystal system, space groupMonoclinic, P21/n
Temperature (K)298
a, b, c (Å)9.383 (4), 7.918 (3), 12.612 (5)
β (°) 109.041 (6)
V3)885.7 (6)
Z4
Radiation typeMo Kα
µ (mm1)9.08
Crystal size (mm)0.20 × 0.12 × 0.10
Data collection
DiffractometerBruker SMART CCD
Absorption correctionEmpirical (using intensity measurements)
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.264, 0.464
No. of measured, independent and
observed [I > 2σ(I)] reflections
4542, 1735, 1346
Rint0.024
(sin θ/λ)max1)0.617
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.036, 0.097, 1.07
No. of reflections1735
No. of parameters93
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.69, 0.34

Computer programs: SMART (Siemens, 1996), SAINT (Siemens, 1994), XPREP (Siemens, 1996), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Sheldrick, 2000), SHELXTL.

Selected geometric parameters (Å, º) top
Br1—C11.889 (4)C5—C71.544 (6)
Br2—C21.902 (4)C4—C81.532 (6)
C2—C1—Br1122.4 (3)C4—C5—C7121.9 (4)
C1—C2—Br2121.2 (3)C5—C4—C8122.4 (4)
 

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