Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536800021127/ob6018sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536800021127/ob6018Isup2.hkl |
CCDC reference: 159720
The title compound, (I), was synthesized in 70% yield by the palladium-catalyzed cross coupling of 4-chlorobenzene boronic acid and 2,3-dichlorobromobenzene (Lehmler & Robertson, 2001; Bauer et al., 1995). Colourless needles were obtained upon crystallization from methanol; m.p. 341–342 K.
Assignment of space group Cc based on systematic absences and intensity statistics. The possibility of the centrosymmetric space group C2/c was discounted by lack of a suitable solution and by the wholly satisfactory refinement in Cc. There were no substantial correlation coefficients in the variance-covariance matrix between parameters sensitive to a missing inversion centre. No formal absorption correction was applied. Face-indexed correction was not feasible because of the crystal morphology. Correction based on multiple measurements of equivalents was attempted but was deemed unsatisfactory. Anisotropic absorption is corrected in a reasonably approximate manner by the inter-frame scaling and merging of equivalents within the data-reduction program SCALEPACK (Otwinowski & Minor, 1997). Subsequent application of an empirical absorption correction based on ΔF2 made no substantive difference to either data or model and so the uncorrected data were employed in refinement.
Data collection: COLLECT (Nonius, 1998); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO-SMN (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL/PC (Sheldrick, 1994); software used to prepare material for publication: SHELX97-2 (Sheldrick, 1997) and local procedures.
Fig. 1. A view of (I) with non-H atom displacement ellipsoids drawn at the 50% probability level. |
C12H7Cl3 | Dx = 1.605 Mg m−3 |
Mr = 257.53 | Melting point = 68–69 K |
Monoclinic, Cc | Mo Kα radiation, λ = 0.71073 Å |
a = 3.901 (1) Å | Cell parameters from 7599 reflections |
b = 17.398 (2) Å | θ = 1.0–27.5° |
c = 15.749 (2) Å | µ = 0.82 mm−1 |
β = 94.51 (1)° | T = 173 K |
V = 1065.6 (3) Å3 | Irregular flattened needles, colourless |
Z = 4 | 0.24 × 0.20 × 0.07 mm |
F(000) = 520 |
Nonius KappaCCD diffractometer | 2197 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.023 |
Graphite monochromator | θmax = 27.5°, θmin = 2.3° |
Detector resolution: 18 pixels mm-1 | h = −4→5 |
ω scans at fixed χ = 55° | k = −22→22 |
4022 measured reflections | l = −20→20 |
2305 independent reflections |
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.026 | w = 1/[σ2(Fo2) + (0.0115P)2 + 0.3392P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.054 | (Δ/σ)max = 0.001 |
S = 1.07 | Δρmax = 0.20 e Å−3 |
2305 reflections | Δρmin = −0.17 e Å−3 |
137 parameters | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
2 restraints | Extinction coefficient: 0.0064 (7) |
Primary atom site location: structure-invariant direct methods | Absolute structure: (Flack, 1983), 1076 Friedel pairs |
Secondary atom site location: difference Fourier map | Absolute structure parameter: −0.02 (5) |
C12H7Cl3 | V = 1065.6 (3) Å3 |
Mr = 257.53 | Z = 4 |
Monoclinic, Cc | Mo Kα radiation |
a = 3.901 (1) Å | µ = 0.82 mm−1 |
b = 17.398 (2) Å | T = 173 K |
c = 15.749 (2) Å | 0.24 × 0.20 × 0.07 mm |
β = 94.51 (1)° |
Nonius KappaCCD diffractometer | 2197 reflections with I > 2σ(I) |
4022 measured reflections | Rint = 0.023 |
2305 independent reflections |
R[F2 > 2σ(F2)] = 0.026 | H-atom parameters constrained |
wR(F2) = 0.054 | Δρmax = 0.20 e Å−3 |
S = 1.07 | Δρmin = −0.17 e Å−3 |
2305 reflections | Absolute structure: (Flack, 1983), 1076 Friedel pairs |
137 parameters | Absolute structure parameter: −0.02 (5) |
2 restraints |
Experimental. 1H-NMR (CDCl3, 400 MHz) δ 7.20 (d, J = 8.0 Hz, d, J = 2.0 Hz, 4-H), 7.25 ("t", J = 8.0 Hz, 5-H), 7.34 (AA'XX' system, 3',5'-H), 7.42 (AA'XX' system, 2',6'-H), 7.48 (d, J = 8.0 Hz, d, J = 2.0 Hz, 6-H); 13C-NMR (CDCl3, 100 MHz) δ 127.23 (C-6), 128.38 (C-2',6'), 129.43 (C-4$), 129.29 (C-5$), 129.50 (C-3',5'), 131.51 (C-2), 133.49 (C-4'*), 133.90 (C-3*), 137.57 (C-1'), 141.58 (C-1) (assignments with (*,$) are interchangeable); IR [cm-1]: 1445, 1415, 1384, 1093, 1013; MS m/z (relative intensity, %): 256 (100, C12H7Cl3.+), 220 (5, M-HCl), 186 (45, M—Cl2), 150 (14). |
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. Refinement of the Flack absolute structure parameter using the SHELXL97 commands TWIN and BASF gave -0.02 (5) for the present model and 1.02 (5) for its inverted counterpart. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.3350 (5) | 0.62904 (10) | 0.90812 (11) | 0.0174 (4) | |
C2 | 0.2276 (5) | 0.64033 (11) | 0.99002 (12) | 0.0197 (4) | |
H2 | 0.1258 | 0.6878 | 1.0041 | 0.024* | |
C3 | 0.2689 (5) | 0.58249 (12) | 1.05089 (12) | 0.0230 (4) | |
H3 | 0.1923 | 0.5899 | 1.1061 | 0.028* | |
C4 | 0.4221 (5) | 0.51421 (11) | 1.03046 (12) | 0.0213 (4) | |
C5 | 0.5279 (5) | 0.50121 (11) | 0.95014 (13) | 0.0224 (4) | |
H5 | 0.6307 | 0.4537 | 0.9367 | 0.027* | |
C6 | 0.4816 (5) | 0.55854 (11) | 0.88965 (12) | 0.0212 (4) | |
H7 | 0.5514 | 0.5497 | 0.8340 | 0.025* | |
C7 | 0.2830 (5) | 0.68775 (11) | 0.83908 (11) | 0.0182 (4) | |
C8 | 0.3923 (5) | 0.76414 (11) | 0.84685 (11) | 0.0176 (4) | |
C9 | 0.3536 (5) | 0.81375 (11) | 0.77730 (11) | 0.0193 (4) | |
C10 | 0.2017 (5) | 0.78876 (12) | 0.69979 (12) | 0.0237 (5) | |
H10 | 0.1773 | 0.8228 | 0.6525 | 0.028* | |
C11 | 0.0853 (5) | 0.71345 (12) | 0.69176 (12) | 0.0234 (5) | |
H11 | −0.0238 | 0.6959 | 0.6393 | 0.028* | |
C12 | 0.1293 (5) | 0.66408 (12) | 0.76062 (11) | 0.0214 (4) | |
H12 | 0.0523 | 0.6125 | 0.7542 | 0.026* | |
Cl1 | 0.47874 (13) | 0.44278 (3) | 1.10768 (3) | 0.03361 (15) | |
Cl2 | 0.58842 (10) | 0.79900 (3) | 0.94221 (3) | 0.02358 (12) | |
Cl3 | 0.50181 (12) | 0.90755 (3) | 0.78489 (3) | 0.02713 (13) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0162 (10) | 0.0186 (9) | 0.0171 (8) | −0.0017 (8) | −0.0008 (7) | −0.0022 (8) |
C2 | 0.0199 (10) | 0.0201 (10) | 0.0192 (9) | −0.0002 (8) | 0.0019 (7) | −0.0021 (7) |
C3 | 0.0226 (11) | 0.0286 (11) | 0.0182 (9) | −0.0020 (9) | 0.0033 (8) | 0.0002 (8) |
C4 | 0.0178 (11) | 0.0228 (11) | 0.0230 (10) | −0.0037 (9) | −0.0012 (8) | 0.0048 (8) |
C5 | 0.0220 (11) | 0.0176 (10) | 0.0277 (10) | −0.0015 (8) | 0.0026 (8) | −0.0035 (9) |
C6 | 0.0230 (11) | 0.0228 (11) | 0.0183 (9) | −0.0016 (9) | 0.0052 (8) | −0.0032 (7) |
C7 | 0.0153 (9) | 0.0213 (10) | 0.0184 (9) | 0.0023 (8) | 0.0037 (7) | −0.0001 (8) |
C8 | 0.0176 (10) | 0.0199 (10) | 0.0153 (8) | 0.0028 (8) | 0.0026 (7) | −0.0039 (7) |
C9 | 0.0177 (10) | 0.0188 (10) | 0.0218 (9) | 0.0030 (8) | 0.0050 (8) | −0.0007 (8) |
C10 | 0.0257 (11) | 0.0266 (11) | 0.0190 (9) | 0.0051 (9) | 0.0031 (8) | 0.0036 (8) |
C11 | 0.0213 (11) | 0.0304 (12) | 0.0184 (9) | −0.0003 (9) | 0.0005 (8) | −0.0033 (8) |
C12 | 0.0229 (11) | 0.0213 (10) | 0.0205 (9) | −0.0026 (9) | 0.0053 (8) | −0.0043 (8) |
Cl1 | 0.0389 (3) | 0.0306 (3) | 0.0314 (3) | 0.0023 (3) | 0.0032 (2) | 0.0135 (2) |
Cl2 | 0.0287 (3) | 0.0216 (2) | 0.0198 (2) | −0.0015 (2) | −0.00219 (18) | −0.00353 (19) |
Cl3 | 0.0350 (3) | 0.0182 (2) | 0.0290 (2) | −0.0007 (2) | 0.0073 (2) | 0.0005 (2) |
C1—C6 | 1.394 (3) | C7—C12 | 1.392 (3) |
C1—C2 | 1.401 (2) | C7—C8 | 1.398 (3) |
C1—C7 | 1.494 (3) | C8—C9 | 1.393 (3) |
C2—C3 | 1.391 (3) | C8—Cl2 | 1.7401 (18) |
C2—H2 | 0.9500 | C9—C10 | 1.384 (3) |
C3—C4 | 1.379 (3) | C9—Cl3 | 1.7323 (19) |
C3—H3 | 0.9500 | C10—C11 | 1.389 (3) |
C4—C5 | 1.380 (3) | C10—H10 | 0.9500 |
C4—Cl1 | 1.7408 (19) | C11—C12 | 1.384 (3) |
C5—C6 | 1.381 (3) | C11—H11 | 0.9500 |
C5—H5 | 0.9500 | C12—H12 | 0.9500 |
C6—H7 | 0.9500 | ||
C6—C1—C2 | 118.22 (17) | C12—C7—C8 | 117.76 (17) |
C6—C1—C7 | 118.97 (16) | C12—C7—C1 | 117.91 (17) |
C2—C1—C7 | 122.73 (17) | C8—C7—C1 | 124.26 (16) |
C3—C2—C1 | 120.42 (18) | C9—C8—C7 | 120.43 (16) |
C3—C2—H2 | 119.8 | C9—C8—Cl2 | 118.40 (15) |
C1—C2—H2 | 119.8 | C7—C8—Cl2 | 121.15 (14) |
C4—C3—C2 | 119.44 (18) | C10—C9—C8 | 120.73 (17) |
C4—C3—H3 | 120.3 | C10—C9—Cl3 | 118.30 (14) |
C2—C3—H3 | 120.3 | C8—C9—Cl3 | 120.96 (14) |
C3—C4—C5 | 121.43 (18) | C9—C10—C11 | 119.38 (18) |
C3—C4—Cl1 | 119.04 (15) | C9—C10—H10 | 120.3 |
C5—C4—Cl1 | 119.53 (16) | C11—C10—H10 | 120.3 |
C4—C5—C6 | 118.80 (18) | C12—C11—C10 | 119.65 (18) |
C4—C5—H5 | 120.6 | C12—C11—H11 | 120.2 |
C6—C5—H5 | 120.6 | C10—C11—H11 | 120.2 |
C5—C6—C1 | 121.68 (17) | C11—C12—C7 | 122.02 (18) |
C5—C6—H7 | 119.2 | C11—C12—H12 | 119.0 |
C1—C6—H7 | 119.2 | C7—C12—H12 | 119.0 |
C6—C1—C2—C3 | 0.3 (3) | C12—C7—C8—C9 | −1.3 (3) |
C7—C1—C2—C3 | 177.21 (19) | C1—C7—C8—C9 | 175.68 (18) |
C1—C2—C3—C4 | 1.1 (3) | C12—C7—C8—Cl2 | −179.78 (15) |
C2—C3—C4—C5 | −1.6 (3) | C1—C7—C8—Cl2 | −2.8 (3) |
C2—C3—C4—Cl1 | 178.98 (16) | C7—C8—C9—C10 | 1.0 (3) |
C3—C4—C5—C6 | 0.7 (3) | Cl2—C8—C9—C10 | 179.51 (17) |
Cl1—C4—C5—C6 | −179.89 (16) | C7—C8—C9—Cl3 | −177.66 (14) |
C4—C5—C6—C1 | 0.7 (3) | Cl2—C8—C9—Cl3 | 0.8 (2) |
C2—C1—C6—C5 | −1.3 (3) | C8—C9—C10—C11 | 0.4 (3) |
C7—C1—C6—C5 | −178.25 (18) | Cl3—C9—C10—C11 | 179.07 (15) |
C6—C1—C7—C12 | 48.0 (3) | C9—C10—C11—C12 | −1.4 (3) |
C2—C1—C7—C12 | −128.8 (2) | C10—C11—C12—C7 | 1.1 (3) |
C6—C1—C7—C8 | −129.0 (2) | C8—C7—C12—C11 | 0.3 (3) |
C2—C1—C7—C8 | 54.2 (3) | C1—C7—C12—C11 | −176.89 (18) |
Experimental details
Crystal data | |
Chemical formula | C12H7Cl3 |
Mr | 257.53 |
Crystal system, space group | Monoclinic, Cc |
Temperature (K) | 173 |
a, b, c (Å) | 3.901 (1), 17.398 (2), 15.749 (2) |
β (°) | 94.51 (1) |
V (Å3) | 1065.6 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.82 |
Crystal size (mm) | 0.24 × 0.20 × 0.07 |
Data collection | |
Diffractometer | Nonius KappaCCD diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4022, 2305, 2197 |
Rint | 0.023 |
(sin θ/λ)max (Å−1) | 0.650 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.026, 0.054, 1.07 |
No. of reflections | 2305 |
No. of parameters | 137 |
No. of restraints | 2 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.20, −0.17 |
Absolute structure | (Flack, 1983), 1076 Friedel pairs |
Absolute structure parameter | −0.02 (5) |
Computer programs: COLLECT (Nonius, 1998), SCALEPACK (Otwinowski & Minor, 1997), DENZO-SMN (Otwinowski & Minor, 1997), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), XP in SHELXTL/PC (Sheldrick, 1994), SHELX97-2 (Sheldrick, 1997) and local procedures.
C1—C7 | 1.494 (3) | C8—Cl2 | 1.7401 (18) |
C4—Cl1 | 1.7408 (19) | C9—Cl3 | 1.7323 (19) |
C6—C1—C7—C12 | 48.0 (3) | C2—C1—C7—C8 | 54.2 (3) |
Polychlorinated biphenyls (PCBs) are persistent and widespread environmental contaminants (Hansen, 1999). Their lipophilic character and resistance to degradation contribute to the tendency of PCBs to accumulate in the food chain, where they present an environmental and human health hazard (Hansen, 1999). The three-dimensional structure of a PCB congener is strongly correlated with its toxicity. For example, derivatives without ortho chlorine substituents, also referred to as `co-planar PCBs', are known to bind to the Ah receptor, and their mechanism of toxicity is well investigated. Recently other targets with differing structural requirements have been identified as affecting several organ systems (Robertson & Hansen, 2001).
Out of 209 possible PCB congeners, only the crystal structures of seven PCB congeners have been described. The bond distances and bond angles in the title compound, (I), are similar to those found in other chlorinated biphenyls [summarized by Miao et al. (1997)]. The torsion angle between the two phenyl rings of PCBs appears to depend on the degree of chlorination at the ortho position. According to published data, mono-ortho, di-ortho and tetra-ortho substituted PCBs show dihedral angles of 49–52, 58–67 and 86–87°, respectively [summarized by Miao et al. (1997) and Singh et al. (1986)]. The dihedral angle of (I), 51.21 (5)°, is the same as those published for PCB congeners with one ortho substituent. The theoretical torsion angles of mono-ortho PCBs calculated by Höfler et al. (1988) are larger (60–72°) than those reported for the solid state. Thus, packing effects appear to influence the torsion angle between the two phenyl rings of PCBs in the solid state.