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The title compound, C
6H
3Br
3O
2, possesses normal geometrical parameters. The crystal packing is controlled by bifurcated O—H
(Br,Br) and O—H
(O,Br) hydrogen bonds and possible weak π–π stacking interactions, resulting in a chiral structure containing a herring-bone-like motif of constituent molecules.
Supporting information
CCDC reference: 234873
Key indicators
- Single-crystal X-ray study
- T = 120 K
- Mean (C-C) = 0.009 Å
- R factor = 0.038
- wR factor = 0.056
- Data-to-parameter ratio = 17.0
checkCIF/PLATON results
No syntax errors found
Alert level C
PLAT341_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ... 9
PLAT431_ALERT_2_C Short Inter HL..A Contact Br1 .. Br2 = 3.51 Ang.
Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
correct. If it is not, please give the correct count in the
_publ_section_exptl_refinement section of the submitted CIF.
From the CIF: _diffrn_reflns_theta_max 27.44
From the CIF: _reflns_number_total 1820
Count of symmetry unique reflns 1118
Completeness (_total/calc) 162.79%
TEST3: Check Friedels for noncentro structure
Estimate of Friedel pairs measured 702
Fraction of Friedel pairs measured 0.628
Are heavy atom types Z>Si present yes
0 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
2 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
1 ALERT type 3 Indicator that the structure quality may be low
1 ALERT type 4 Improvement, methodology, query or suggestion
Data collection: COLLECT (Nonius, 1998); cell refinement: HKL SCALEPACK (Otwinowski & Minor 1997); data reduction: HKL DENZO and SCALEPACK (Otwinowski & Minor 1997) and SORTAV (Blessing, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.
Crystal data top
C6H3Br3O2 | Dx = 2.853 Mg m−3 |
Mr = 346.81 | Melting point: 280 K |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 12216 reflections |
a = 4.1071 (3) Å | θ = 2.9–27.5° |
b = 12.855 (1) Å | µ = 14.93 mm−1 |
c = 15.296 (1) Å | T = 120 K |
V = 807.6 (1) Å3 | Needle, colourless |
Z = 4 | 0.38 × 0.04 × 0.03 mm |
F(000) = 640 | |
Data collection top
Enraf-Nonius KappaCCD diffractometer | 1820 independent reflections |
Radiation source: fine-focus sealed tube | 1390 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.066 |
ω and φ scans | θmax = 27.4°, θmin = 3.1° |
Absorption correction: multi-scan (SORTAV; Blessing, 1995) | h = −5→5 |
Tmin = 0.067, Tmax = 0.636 | k = −16→16 |
7322 measured reflections | l = −17→19 |
Refinement top
Refinement on F2 | Hydrogen site location: difmap (O-H) and geom (C-H) |
Least-squares matrix: full | H atoms treated by a mixture of independent and constrained refinement |
R[F2 > 2σ(F2)] = 0.038 | w = 1/[σ2(Fo2) + (0.0143P)2] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.056 | (Δ/σ)max < 0.001 |
S = 1.00 | Δρmax = 0.73 e Å−3 |
1820 reflections | Δρmin = −0.63 e Å−3 |
107 parameters | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 restraints | Extinction coefficient: 0.0021 (3) |
Primary atom site location: structure-invariant direct methods | Absolute structure: Flack H D (1983), 727 Friedel pairs |
Secondary atom site location: difference Fourier map | Absolute structure parameter: 0.04 (3) |
Special details top
Experimental. Melting points were determined on a Gallenkamp melting point apparatus and are
uncorrected. IR measurements were recorded on a ATI Mattson Genesis FTIR
spectrometer. 250 MHz 1H and 62.5 MHz 13C NMR spectra were determined on a
Bruker 250 MHz s pectrometer. TLC chromatography plates were aluminium backed
with a coating of Merck 60 F254 silica. |
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 | x | y | z | Uiso*/Ueq | |
C1 | 0.7209 (15) | −0.0499 (4) | 0.4241 (4) | 0.0172 (14) | |
C2 | 0.6566 (14) | 0.0039 (4) | 0.3483 (4) | 0.0167 (15) | |
C3 | 0.4764 (15) | 0.0959 (4) | 0.3527 (4) | 0.0172 (15) | |
C4 | 0.3643 (14) | 0.1321 (5) | 0.4326 (4) | 0.0192 (14) | |
H4 | 0.2428 | 0.1949 | 0.4357 | 0.023* | |
C5 | 0.4303 (15) | 0.0766 (4) | 0.5075 (4) | 0.0148 (14) | |
C6 | 0.6087 (15) | −0.0159 (4) | 0.5058 (4) | 0.0176 (14) | |
O1 | 0.7570 (11) | −0.0285 (3) | 0.2683 (3) | 0.0237 (11) | |
H1 | 0.849 (14) | −0.085 (4) | 0.270 (4) | 0.028* | |
O2 | 0.6795 (11) | −0.0752 (3) | 0.5767 (3) | 0.0219 (12) | |
H2 | 0.634 (16) | −0.043 (5) | 0.617 (4) | 0.026* | |
Br1 | 0.95355 (16) | −0.17647 (5) | 0.41737 (4) | 0.02168 (17) | |
Br2 | 0.38328 (13) | 0.17109 (5) | 0.24986 (4) | 0.02274 (18) | |
Br3 | 0.26244 (16) | 0.12500 (5) | 0.61575 (4) | 0.02241 (18) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.022 (3) | 0.012 (3) | 0.018 (4) | 0.004 (3) | −0.003 (3) | −0.003 (3) |
C2 | 0.017 (4) | 0.021 (3) | 0.013 (4) | −0.008 (3) | 0.002 (3) | −0.003 (3) |
C3 | 0.019 (3) | 0.017 (3) | 0.015 (4) | 0.001 (3) | −0.006 (3) | 0.003 (3) |
C4 | 0.021 (4) | 0.015 (3) | 0.022 (4) | −0.001 (3) | −0.006 (3) | 0.001 (3) |
C5 | 0.017 (3) | 0.019 (3) | 0.008 (3) | −0.002 (3) | 0.003 (3) | −0.002 (3) |
C6 | 0.024 (3) | 0.016 (3) | 0.013 (4) | −0.006 (3) | −0.006 (3) | 0.005 (3) |
O1 | 0.033 (2) | 0.020 (2) | 0.018 (3) | 0.004 (2) | 0.005 (2) | −0.003 (2) |
O2 | 0.031 (3) | 0.020 (2) | 0.015 (3) | 0.000 (2) | 0.001 (2) | 0.0017 (19) |
Br1 | 0.0239 (3) | 0.0182 (3) | 0.0230 (4) | 0.0023 (3) | −0.0018 (3) | −0.0014 (3) |
Br2 | 0.0281 (3) | 0.0229 (3) | 0.0173 (4) | 0.0016 (3) | −0.0019 (3) | 0.0025 (3) |
Br3 | 0.0245 (3) | 0.0252 (3) | 0.0175 (3) | 0.0024 (3) | 0.0016 (3) | −0.0007 (3) |
Geometric parameters (Å, º) top
C1—C2 | 1.376 (8) | C4—C5 | 1.377 (8) |
C1—C6 | 1.401 (8) | C4—H4 | 0.9500 |
C1—Br1 | 1.890 (5) | C5—C6 | 1.397 (8) |
C2—O1 | 1.358 (7) | C5—Br3 | 1.898 (6) |
C2—C3 | 1.396 (7) | C6—O2 | 1.358 (7) |
C3—C4 | 1.387 (8) | O1—H1 | 0.82 (5) |
C3—Br2 | 1.886 (6) | O2—H2 | 0.77 (6) |
| | | |
C2—C1—C6 | 122.1 (5) | C5—C4—H4 | 120.2 |
C2—C1—Br1 | 119.0 (5) | C3—C4—H4 | 120.2 |
C6—C1—Br1 | 118.9 (4) | C4—C5—C6 | 121.9 (5) |
O1—C2—C1 | 123.2 (5) | C4—C5—Br3 | 118.9 (5) |
O1—C2—C3 | 117.7 (5) | C6—C5—Br3 | 119.1 (4) |
C1—C2—C3 | 119.2 (5) | O2—C6—C5 | 125.1 (5) |
C4—C3—C2 | 120.2 (5) | O2—C6—C1 | 117.9 (5) |
C4—C3—Br2 | 119.7 (4) | C5—C6—C1 | 117.1 (5) |
C2—C3—Br2 | 120.1 (5) | C2—O1—H1 | 112 (5) |
C5—C4—C3 | 119.6 (5) | C6—O2—H2 | 107 (5) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···Br1 | 0.82 (5) | 2.57 (6) | 3.078 (4) | 121 (5) |
O1—H1···Br3i | 0.82 (5) | 2.90 (6) | 3.298 (4) | 112 (5) |
O2—H2···O1ii | 0.77 (6) | 2.52 (6) | 3.229 (6) | 153 (6) |
O2—H2···Br3 | 0.77 (6) | 2.64 (6) | 3.148 (4) | 125 (6) |
Symmetry codes: (i) −x+3/2, −y, z−1/2; (ii) −x+3/2, −y, z+1/2. |
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