The title compound, C
14H
10Cl
2, crystallizes as colourless prisms with two symmetry-independent molecules in the unit cell. Numerous intermolecular C—H
π interactions dominate in the crystal structure, where C—H
Cl and long Cl
Cl contacts are also observed.
Supporting information
CCDC reference: 628521
The title compound, DDNU, was obtained from the electrolysis of DDT in the ionic liquid system of 1-butyl-3-methylimidazolium tetrafluoroborate, [bmim]BF4, with a carbon felt electrode (CFE) (area 3 × 1 cm2) containing a catalytic amount of a hydrophobic vitamin B12 derivative at an applied potential of −1.5 V versus Ag/AgCl. Single crystals suitable for X-ray analysis were obtained by slow evaporation of a solution of DDNU in chloroform–ethanol (1:1 v/v) to give colourless prisms within 3–4 d.
H atoms were located in geometric positions (C—H = 0.94–0.98 Å) and refined as riding, with Uiso(H) = 1.2Ueq(C) or 1.5Ueq(methyl C). The residual electron-density map contained small peaks of electron density (ca 0.53 e Å−3) in the vicinity of atom Cl2.
Data collection: SMART (Bruker, 2001); cell refinement: SMART; data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2001); software used to prepare material for publication: SHELXTL.
1,1'-(ethenylidene)bis(4-chlorobenzene)
top
Crystal data top
C14H10Cl2 | Z = 4 |
Mr = 249.12 | F(000) = 512 |
Triclinic, P1 | Dx = 1.368 Mg m−3 |
Hall symbol: -P 1 | Melting point: 358.0 K |
a = 9.715 (2) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 9.745 (2) Å | Cell parameters from 1592 reflections |
c = 13.868 (2) Å | θ = 2.4–25.7° |
α = 91.210 (4)° | µ = 0.50 mm−1 |
β = 102.457 (3)° | T = 173 K |
γ = 108.561 (4)° | Prism, colourless |
V = 1209.6 (4) Å3 | 0.25 × 0.10 × 0.10 mm |
Data collection top
Bruker SMART APEX CCD area-detector diffractometer | 4553 independent reflections |
Radiation source: fine-focus sealed tube | 2835 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.026 |
Detector resolution: 8.366 pixels mm-1 | θmax = 25.7°, θmin = 1.5° |
ϕ and ω scans | h = −11→5 |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | k = −11→11 |
Tmin = 0.884, Tmax = 0.951 | l = −16→16 |
7314 measured reflections | |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.055 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.155 | H-atom parameters constrained |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0845P)2] where P = (Fo2 + 2Fc2)/3 |
4553 reflections | (Δ/σ)max = 0.001 |
289 parameters | Δρmax = 0.53 e Å−3 |
0 restraints | Δρmin = −0.38 e Å−3 |
Crystal data top
C14H10Cl2 | γ = 108.561 (4)° |
Mr = 249.12 | V = 1209.6 (4) Å3 |
Triclinic, P1 | Z = 4 |
a = 9.715 (2) Å | Mo Kα radiation |
b = 9.745 (2) Å | µ = 0.50 mm−1 |
c = 13.868 (2) Å | T = 173 K |
α = 91.210 (4)° | 0.25 × 0.10 × 0.10 mm |
β = 102.457 (3)° | |
Data collection top
Bruker SMART APEX CCD area-detector diffractometer | 4553 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 2835 reflections with I > 2σ(I) |
Tmin = 0.884, Tmax = 0.951 | Rint = 0.026 |
7314 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.055 | 0 restraints |
wR(F2) = 0.155 | H-atom parameters constrained |
S = 1.00 | Δρmax = 0.53 e Å−3 |
4553 reflections | Δρmin = −0.38 e Å−3 |
289 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 | x | y | z | Uiso*/Ueq | |
C1 | 0.5475 (4) | 0.4755 (4) | 0.7359 (3) | 0.0645 (12) | |
H1A | 0.5935 | 0.5099 | 0.6832 | 0.077* | |
H1B | 0.5949 | 0.5173 | 0.8020 | 0.077* | |
C2 | 0.4157 (4) | 0.3681 (3) | 0.7169 (2) | 0.0400 (8) | |
C3 | 0.3429 (3) | 0.3179 (3) | 0.7993 (2) | 0.0349 (7) | |
C4 | 0.3409 (4) | 0.4170 (3) | 0.8719 (2) | 0.0490 (9) | |
H4 | 0.3814 | 0.5181 | 0.8661 | 0.059* | |
C5 | 0.2817 (4) | 0.3727 (4) | 0.9523 (3) | 0.0529 (10) | |
H5 | 0.2807 | 0.4422 | 1.0010 | 0.063* | |
C6 | 0.2241 (4) | 0.2266 (3) | 0.9611 (2) | 0.0404 (8) | |
C7 | 0.2210 (3) | 0.1243 (3) | 0.8895 (2) | 0.0373 (7) | |
H7 | 0.1795 | 0.0235 | 0.8958 | 0.045* | |
C8 | 0.2790 (3) | 0.1701 (3) | 0.8088 (2) | 0.0338 (7) | |
H8 | 0.2753 | 0.0999 | 0.7588 | 0.041* | |
C9 | 0.3389 (3) | 0.3007 (3) | 0.6148 (2) | 0.0317 (7) | |
C10 | 0.4187 (4) | 0.3002 (3) | 0.5414 (2) | 0.0407 (8) | |
H10 | 0.5246 | 0.3406 | 0.5586 | 0.049* | |
C11 | 0.3467 (4) | 0.2422 (3) | 0.4446 (2) | 0.0430 (8) | |
H11 | 0.4025 | 0.2434 | 0.3960 | 0.052* | |
C12 | 0.1933 (4) | 0.1829 (3) | 0.4198 (2) | 0.0358 (7) | |
C13 | 0.1113 (3) | 0.1802 (3) | 0.4894 (2) | 0.0336 (7) | |
H13 | 0.0055 | 0.1388 | 0.4714 | 0.040* | |
C14 | 0.1842 (3) | 0.2386 (3) | 0.5860 (2) | 0.0323 (7) | |
H14 | 0.1269 | 0.2362 | 0.6338 | 0.039* | |
C15 | 0.5282 (4) | 0.9888 (3) | 0.7318 (3) | 0.0489 (9) | |
H15A | 0.5630 | 1.0267 | 0.6757 | 0.059* | |
H15B | 0.5813 | 1.0332 | 0.7966 | 0.059* | |
C16 | 0.4040 (3) | 0.8725 (3) | 0.7196 (2) | 0.0339 (7) | |
C17 | 0.3459 (3) | 0.8161 (3) | 0.8073 (2) | 0.0312 (7) | |
C18 | 0.4404 (3) | 0.8331 (3) | 0.9008 (2) | 0.0374 (7) | |
H18 | 0.5452 | 0.8754 | 0.9083 | 0.045* | |
C19 | 0.3849 (4) | 0.7898 (3) | 0.9832 (2) | 0.0406 (8) | |
H19 | 0.4509 | 0.8029 | 1.0467 | 0.049* | |
C20 | 0.2340 (4) | 0.7280 (3) | 0.9722 (2) | 0.0360 (7) | |
C21 | 0.1370 (3) | 0.7058 (3) | 0.8803 (2) | 0.0349 (7) | |
H21 | 0.0327 | 0.6607 | 0.8732 | 0.042* | |
C22 | 0.1932 (3) | 0.7497 (3) | 0.7988 (2) | 0.0314 (7) | |
H22 | 0.1264 | 0.7345 | 0.7354 | 0.038* | |
C23 | 0.3208 (3) | 0.8027 (3) | 0.6192 (2) | 0.0309 (7) | |
C24 | 0.3011 (3) | 0.8858 (3) | 0.5395 (2) | 0.0370 (7) | |
H24 | 0.3395 | 0.9889 | 0.5511 | 0.044* | |
C25 | 0.2278 (3) | 0.8225 (3) | 0.4450 (2) | 0.0390 (8) | |
H25 | 0.2156 | 0.8812 | 0.3922 | 0.047* | |
C26 | 0.1721 (3) | 0.6729 (3) | 0.4277 (2) | 0.0362 (7) | |
C27 | 0.1893 (3) | 0.5869 (3) | 0.5043 (2) | 0.0355 (7) | |
H27 | 0.1511 | 0.4840 | 0.4919 | 0.043* | |
C28 | 0.2621 (3) | 0.6512 (3) | 0.5988 (2) | 0.0328 (7) | |
H28 | 0.2726 | 0.5916 | 0.6513 | 0.039* | |
Cl1 | 0.15956 (11) | 0.17002 (11) | 1.06587 (7) | 0.0607 (3) | |
Cl2 | 0.10185 (11) | 0.10435 (11) | 0.29940 (6) | 0.0584 (3) | |
Cl3 | 0.16417 (11) | 0.67587 (9) | 1.07610 (6) | 0.0553 (3) | |
Cl4 | 0.07636 (11) | 0.59175 (10) | 0.30846 (6) | 0.0556 (3) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.056 (2) | 0.050 (2) | 0.064 (3) | −0.006 (2) | 0.001 (2) | 0.0153 (19) |
C2 | 0.0401 (19) | 0.0279 (16) | 0.0500 (19) | 0.0101 (15) | 0.0077 (16) | 0.0137 (14) |
C3 | 0.0381 (18) | 0.0224 (15) | 0.0409 (17) | 0.0102 (14) | 0.0019 (14) | 0.0048 (13) |
C4 | 0.071 (2) | 0.0237 (16) | 0.047 (2) | 0.0153 (17) | 0.0022 (19) | 0.0004 (14) |
C5 | 0.075 (3) | 0.0391 (19) | 0.047 (2) | 0.0296 (19) | 0.0056 (19) | −0.0065 (16) |
C6 | 0.0423 (19) | 0.0422 (19) | 0.0407 (18) | 0.0192 (16) | 0.0099 (15) | 0.0033 (14) |
C7 | 0.0406 (18) | 0.0280 (15) | 0.0434 (18) | 0.0111 (14) | 0.0105 (15) | 0.0023 (13) |
C8 | 0.0383 (18) | 0.0225 (14) | 0.0379 (16) | 0.0082 (13) | 0.0065 (14) | −0.0008 (12) |
C9 | 0.0297 (16) | 0.0200 (14) | 0.0483 (18) | 0.0097 (13) | 0.0120 (14) | 0.0142 (13) |
C10 | 0.0336 (17) | 0.0337 (17) | 0.061 (2) | 0.0132 (15) | 0.0186 (16) | 0.0213 (15) |
C11 | 0.051 (2) | 0.0435 (19) | 0.052 (2) | 0.0248 (17) | 0.0317 (17) | 0.0237 (16) |
C12 | 0.048 (2) | 0.0306 (16) | 0.0397 (17) | 0.0220 (15) | 0.0178 (15) | 0.0170 (13) |
C13 | 0.0325 (16) | 0.0284 (15) | 0.0428 (17) | 0.0103 (13) | 0.0135 (14) | 0.0119 (13) |
C14 | 0.0365 (17) | 0.0267 (15) | 0.0404 (17) | 0.0134 (14) | 0.0175 (14) | 0.0109 (13) |
C15 | 0.045 (2) | 0.0397 (18) | 0.055 (2) | −0.0018 (16) | 0.0219 (17) | −0.0039 (16) |
C16 | 0.0354 (17) | 0.0233 (15) | 0.0492 (19) | 0.0111 (14) | 0.0206 (15) | 0.0031 (13) |
C17 | 0.0321 (17) | 0.0186 (14) | 0.0448 (18) | 0.0105 (13) | 0.0100 (14) | 0.0025 (12) |
C18 | 0.0316 (17) | 0.0250 (15) | 0.0509 (19) | 0.0054 (14) | 0.0067 (15) | −0.0028 (14) |
C19 | 0.044 (2) | 0.0347 (17) | 0.0393 (18) | 0.0124 (16) | 0.0028 (15) | −0.0030 (14) |
C20 | 0.047 (2) | 0.0258 (15) | 0.0368 (17) | 0.0111 (15) | 0.0148 (15) | 0.0025 (13) |
C21 | 0.0382 (18) | 0.0245 (15) | 0.0433 (18) | 0.0084 (14) | 0.0156 (15) | 0.0030 (13) |
C22 | 0.0337 (17) | 0.0231 (14) | 0.0386 (16) | 0.0098 (13) | 0.0100 (14) | 0.0055 (12) |
C23 | 0.0276 (15) | 0.0228 (14) | 0.0472 (18) | 0.0086 (13) | 0.0186 (14) | 0.0072 (13) |
C24 | 0.0383 (18) | 0.0269 (15) | 0.0518 (19) | 0.0101 (14) | 0.0234 (16) | 0.0115 (14) |
C25 | 0.0417 (19) | 0.0388 (18) | 0.0462 (19) | 0.0166 (15) | 0.0238 (16) | 0.0222 (15) |
C26 | 0.0325 (17) | 0.0405 (18) | 0.0405 (17) | 0.0110 (15) | 0.0198 (14) | 0.0075 (14) |
C27 | 0.0374 (18) | 0.0274 (15) | 0.0431 (18) | 0.0087 (14) | 0.0150 (15) | 0.0062 (13) |
C28 | 0.0367 (17) | 0.0221 (14) | 0.0418 (17) | 0.0084 (13) | 0.0153 (14) | 0.0065 (12) |
Cl1 | 0.0672 (6) | 0.0765 (7) | 0.0487 (5) | 0.0294 (5) | 0.0263 (5) | 0.0064 (5) |
Cl2 | 0.0772 (7) | 0.0758 (6) | 0.0361 (5) | 0.0443 (6) | 0.0126 (4) | 0.0104 (4) |
Cl3 | 0.0742 (7) | 0.0505 (5) | 0.0398 (5) | 0.0126 (5) | 0.0220 (4) | 0.0075 (4) |
Cl4 | 0.0636 (6) | 0.0610 (6) | 0.0377 (5) | 0.0126 (5) | 0.0148 (4) | 0.0039 (4) |
Geometric parameters (Å, º) top
C1—C2 | 1.339 (5) | C15—C16 | 1.342 (4) |
C1—H1A | 0.9500 | C15—H15A | 0.9500 |
C1—H1B | 0.9500 | C15—H15B | 0.9500 |
C2—C9 | 1.477 (4) | C16—C23 | 1.476 (4) |
C2—C3 | 1.483 (4) | C16—C17 | 1.492 (4) |
C3—C4 | 1.389 (4) | C17—C18 | 1.390 (4) |
C3—C8 | 1.397 (4) | C17—C22 | 1.394 (4) |
C4—C5 | 1.377 (5) | C18—C19 | 1.383 (4) |
C4—H4 | 0.9500 | C18—H18 | 0.9500 |
C5—C6 | 1.373 (4) | C19—C20 | 1.368 (4) |
C5—H5 | 0.9500 | C19—H19 | 0.9500 |
C6—C7 | 1.380 (4) | C20—C21 | 1.378 (4) |
C6—Cl1 | 1.737 (3) | C20—Cl3 | 1.740 (3) |
C7—C8 | 1.379 (4) | C21—C22 | 1.377 (4) |
C7—H7 | 0.9500 | C21—H21 | 0.9500 |
C8—H8 | 0.9500 | C22—H22 | 0.9500 |
C9—C14 | 1.391 (4) | C23—C24 | 1.400 (4) |
C9—C10 | 1.408 (4) | C23—C28 | 1.401 (4) |
C10—C11 | 1.385 (5) | C24—C25 | 1.374 (4) |
C10—H10 | 0.9500 | C24—H24 | 0.9500 |
C11—C12 | 1.376 (4) | C25—C26 | 1.380 (4) |
C11—H11 | 0.9500 | C25—H25 | 0.9500 |
C12—C13 | 1.373 (4) | C26—C27 | 1.381 (4) |
C12—Cl2 | 1.743 (3) | C26—Cl4 | 1.743 (3) |
C13—C14 | 1.386 (4) | C27—C28 | 1.375 (4) |
C13—H13 | 0.9500 | C27—H27 | 0.9500 |
C14—H14 | 0.9500 | C28—H28 | 0.9500 |
| | | |
C2—C1—H1A | 120.0 | C16—C15—H15A | 120.0 |
C2—C1—H1B | 120.0 | C16—C15—H15B | 120.0 |
H1A—C1—H1B | 120.0 | H15A—C15—H15B | 120.0 |
C1—C2—C9 | 121.4 (3) | C15—C16—C23 | 120.4 (3) |
C1—C2—C3 | 119.5 (3) | C15—C16—C17 | 120.1 (3) |
C9—C2—C3 | 119.0 (3) | C23—C16—C17 | 119.5 (2) |
C4—C3—C8 | 117.7 (3) | C18—C17—C22 | 117.6 (3) |
C4—C3—C2 | 120.8 (3) | C18—C17—C16 | 121.6 (3) |
C8—C3—C2 | 121.5 (3) | C22—C17—C16 | 120.8 (3) |
C5—C4—C3 | 121.8 (3) | C19—C18—C17 | 121.3 (3) |
C5—C4—H4 | 119.1 | C19—C18—H18 | 119.3 |
C3—C4—H4 | 119.1 | C17—C18—H18 | 119.3 |
C6—C5—C4 | 119.1 (3) | C20—C19—C18 | 119.3 (3) |
C6—C5—H5 | 120.5 | C20—C19—H19 | 120.3 |
C4—C5—H5 | 120.5 | C18—C19—H19 | 120.3 |
C5—C6—C7 | 121.1 (3) | C19—C20—C21 | 121.0 (3) |
C5—C6—Cl1 | 119.3 (3) | C19—C20—Cl3 | 119.3 (2) |
C7—C6—Cl1 | 119.6 (2) | C21—C20—Cl3 | 119.7 (2) |
C8—C7—C6 | 119.3 (3) | C22—C21—C20 | 119.2 (3) |
C8—C7—H7 | 120.4 | C22—C21—H21 | 120.4 |
C6—C7—H7 | 120.4 | C20—C21—H21 | 120.4 |
C7—C8—C3 | 121.1 (3) | C21—C22—C17 | 121.4 (3) |
C7—C8—H8 | 119.5 | C21—C22—H22 | 119.3 |
C3—C8—H8 | 119.5 | C17—C22—H22 | 119.3 |
C14—C9—C10 | 116.8 (3) | C24—C23—C28 | 117.1 (3) |
C14—C9—C2 | 121.7 (3) | C24—C23—C16 | 121.1 (3) |
C10—C9—C2 | 121.4 (3) | C28—C23—C16 | 121.7 (3) |
C11—C10—C9 | 121.6 (3) | C25—C24—C23 | 121.8 (3) |
C11—C10—H10 | 119.2 | C25—C24—H24 | 119.1 |
C9—C10—H10 | 119.2 | C23—C24—H24 | 119.1 |
C12—C11—C10 | 119.2 (3) | C24—C25—C26 | 119.4 (3) |
C12—C11—H11 | 120.4 | C24—C25—H25 | 120.3 |
C10—C11—H11 | 120.4 | C26—C25—H25 | 120.3 |
C13—C12—C11 | 121.0 (3) | C25—C26—C27 | 120.6 (3) |
C13—C12—Cl2 | 119.3 (2) | C25—C26—Cl4 | 119.6 (2) |
C11—C12—Cl2 | 119.6 (2) | C27—C26—Cl4 | 119.8 (2) |
C12—C13—C14 | 119.5 (3) | C28—C27—C26 | 119.7 (3) |
C12—C13—H13 | 120.3 | C28—C27—H27 | 120.2 |
C14—C13—H13 | 120.3 | C26—C27—H27 | 120.2 |
C13—C14—C9 | 121.9 (3) | C27—C28—C23 | 121.4 (3) |
C13—C14—H14 | 119.1 | C27—C28—H28 | 119.3 |
C9—C14—H14 | 119.1 | C23—C28—H28 | 119.3 |
| | | |
C1—C2—C3—C4 | 42.3 (5) | C15—C16—C17—C18 | −28.5 (4) |
C9—C2—C3—C4 | −136.1 (3) | C23—C16—C17—C18 | 153.8 (3) |
C1—C2—C3—C8 | −135.4 (3) | C15—C16—C17—C22 | 148.7 (3) |
C9—C2—C3—C8 | 46.2 (4) | C23—C16—C17—C22 | −29.0 (4) |
C8—C3—C4—C5 | 1.6 (5) | C22—C17—C18—C19 | −1.9 (4) |
C2—C3—C4—C5 | −176.1 (3) | C16—C17—C18—C19 | 175.4 (3) |
C3—C4—C5—C6 | 0.5 (5) | C17—C18—C19—C20 | 0.5 (4) |
C4—C5—C6—C7 | −1.8 (5) | C18—C19—C20—C21 | 1.2 (4) |
C4—C5—C6—Cl1 | 176.2 (3) | C18—C19—C20—Cl3 | −179.1 (2) |
C5—C6—C7—C8 | 1.0 (5) | C19—C20—C21—C22 | −1.5 (4) |
Cl1—C6—C7—C8 | −177.0 (2) | Cl3—C20—C21—C22 | 178.9 (2) |
C6—C7—C8—C3 | 1.1 (5) | C20—C21—C22—C17 | 0.0 (4) |
C4—C3—C8—C7 | −2.4 (5) | C18—C17—C22—C21 | 1.6 (4) |
C2—C3—C8—C7 | 175.3 (3) | C16—C17—C22—C21 | −175.7 (3) |
C1—C2—C9—C14 | −152.2 (3) | C15—C16—C23—C24 | −39.8 (4) |
C3—C2—C9—C14 | 26.2 (4) | C17—C16—C23—C24 | 137.9 (3) |
C1—C2—C9—C10 | 25.9 (4) | C15—C16—C23—C28 | 138.3 (3) |
C3—C2—C9—C10 | −155.7 (3) | C17—C16—C23—C28 | −43.9 (4) |
C14—C9—C10—C11 | 0.7 (4) | C28—C23—C24—C25 | −0.2 (4) |
C2—C9—C10—C11 | −177.4 (3) | C16—C23—C24—C25 | 178.0 (3) |
C9—C10—C11—C12 | −0.4 (4) | C23—C24—C25—C26 | −0.2 (5) |
C10—C11—C12—C13 | −0.1 (4) | C24—C25—C26—C27 | 0.1 (5) |
C10—C11—C12—Cl2 | −177.9 (2) | C24—C25—C26—Cl4 | 179.0 (2) |
C11—C12—C13—C14 | 0.2 (4) | C25—C26—C27—C28 | 0.2 (5) |
Cl2—C12—C13—C14 | 178.0 (2) | Cl4—C26—C27—C28 | −178.6 (2) |
C12—C13—C14—C9 | 0.2 (4) | C26—C27—C28—C23 | −0.6 (5) |
C10—C9—C14—C13 | −0.6 (4) | C24—C23—C28—C27 | 0.6 (4) |
C2—C9—C14—C13 | 177.5 (2) | C16—C23—C28—C27 | −177.6 (3) |
Experimental details
Crystal data |
Chemical formula | C14H10Cl2 |
Mr | 249.12 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 173 |
a, b, c (Å) | 9.715 (2), 9.745 (2), 13.868 (2) |
α, β, γ (°) | 91.210 (4), 102.457 (3), 108.561 (4) |
V (Å3) | 1209.6 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.50 |
Crystal size (mm) | 0.25 × 0.10 × 0.10 |
|
Data collection |
Diffractometer | Bruker SMART APEX CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.884, 0.951 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7314, 4553, 2835 |
Rint | 0.026 |
(sin θ/λ)max (Å−1) | 0.610 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.055, 0.155, 1.00 |
No. of reflections | 4553 |
No. of parameters | 289 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.53, −0.38 |
Comparison of unit-cell parameters of DDNU, DDMU, DDE and DDT topCompound | DDNUa | DDMUb | DDEc | DDTd |
a(Å) | 9.715 (2) | 15.163 (7) | 9.219 (1) | 9.963 (1) |
b(Å) | 9.745 (2) | 5.824 (2) | 35.496 (5) | 19.200 (2) |
c(Å) | 13.868 (2) | 7.452 (3) | 9.438 (1) | 7.887 (1) |
α° | 91.210 (4) | | | |
β° | 102.457 (3) | 100.12 (3) | 114.70 (1) | |
γ° | 108.561 (4) | | | |
V(Å)3 | 1209 | 648 | 3088 | 1509 |
Space group | P1 | P21 | P21/c | Pca21 |
References: (a) this work; (b) Kennard et al., 1984; (c) Shields et al., 1977; (d) DeLacy & Kennard, 1972. |
Comparison of selected bond lengths (Å) at the terminal C atom between DDNU, DDMU, DDE and DDT topCompound | DDNUa | DDMUb | DDEc | DDTd |
C1-C2 | 1.339 (5) | 1.296 (1) | 1.320 (1) | 1.540 (4) |
C15-C16 | 1.342 (4) | | 1.322 (1) | |
C2-C3 | 1.483 (4) | 1.483 | 1.487 (9) | 1.531 (4) |
C16-C17 | 1.492 (4) | | 1.491 (9) | |
C2-C9 | 1.477 (4) | 1.515 (8) | 1.492 (1) | 1.522 (8) |
C16-C23 | 1.476 (4) | | 1.471 (1) | |
References: (a) this work; (b) Kennard et al. (1984); (c) Shields et al. (1977); (d) DeLacy & Kennard (1972). |
Geometry of C—H···π interactions (Å, °) for DDNU topD—H···A | D—H | H···A | D···A | D—H···A |
C27—H27···Cg1 | 0.950 | 2.918 | 3.676 | 137 |
C24—H24···Cg1i | 0.950 | 2.793 | 3.599 | 143 |
C19—H19···Cg2ii | 0.950 | 2.897 | 3.614 | 133 |
C13—H13···Cg3iii | 0.950 | 3.063 | 3.773 | 132 |
Symmetry codes: (i) x, y + 1, z; (ii) 1 − x, 1 − y, 2 − z; (iii) −x, 1 − y, 1 − z. Cg1, Cg2 and Cg3 are centroids of rings C9–C14, C3–C8 and C23–C28, respectively. |
Comparison of selected torsion angles (°) for DDNU, DDMU and DDE topCompound | DDNUa | DDMUb | DDEc |
C1-C2-C9-C14 | -152.18 (3) | 104.0 (1) | 127.0 (1) |
C1-C2-C3-C8 | -135.39 (4) | -38.0 (1) | -52.0 (1) |
C15-C16-C17-C22 | 148.70 (3) | | 121.0 (1) |
C15-C16-C23-C28 | 138.30 (4) | | -48.3 (1) |
References: (a) this work; (b) Kennard et al. (1984); (c) Shields et al. (1977). |
1,1-Bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) has been recognized as one of the most problematic persistent organic pollutants (POPs). These compounds are relatively recent in origin, dating to the boom in industrial production after World War II. It has been found that DDT causes serious health and developmental problems in humans and wildlife even at low concentrations (Fellenberg, 2000). Therefore, extensive studies have been carried out using several methods for the degradation of DDT (Alonso et al., 2002; Häggblom & Bossert, 2003). Recently, the partial electrochemical dechlorination of DDT mediated by a hydrophobic cobalamin derivative (hydrophobic vitamin B12) yielded various dechlorinated products, such as 1,1-bis(4-chlorophenyl)-2,2-dichloroethane (DDD), 1,1-bis(4-chlorophenyl)-2,2-dichloroethylene (DDE), 1,1,4,4-tetrakis(4-chlorophenyl)-2,3-dichloro-2-butene (TTDB) and 1-chloro-2,2-bis(4-chlorophenyl)ethylene (DDMU) (Shimakoshi, Tokunaga & Hisaeda, 2004). Structural data for DDD, DDE and DDMU from the viewpoint of toxicity have been reported (Shields et al., 1977; Kennard et al., 1984). We have also reported the crystal structure and geometry of E-TTDB (Shimakoshi, Aritome et al. 2004) and Z-TTDB (Shimakoshi et al., 2005). With increasing environmental concern, it is imperative that new environmentally friendly approaches for the dechlorination of DDT be developed. To achieve this, DDT was dechlorinated in an ionic liquid system, 1-butyl-3-methylimidazolium tetrafluoroborate, [bmim]BF4, and the title compound, 1,1'-(ethenylidene)bis(4-chlorobenzene), DDNU, was obtained as one of the dechlorinated products. The ionic liquid system was briefly explained by Sheldon (2001) and Welton (1999). In this paper, the crystal structure of DDNU is reported in comparison with those of DDT and its metabolites.
DDNU crystallizes as colourless prisms with two symmetry-independent molecules, 1 and 2, in the asymmetric unit (Fig. 1). The two independent molecules are an approximate inverted image of each other, although the aryl rings cannot be superimposed exactly. The dihedral angles between the two aryl planes are 63.59 (11) and 63.86 (10)° for molecules 1 and 2, respectively, and the aryl rings are not related by symmetry, while in DDT and its analogues there is mirror symmetry between the two aryl rings. The butterfly configuration of DDNU is distorted compared with that of DDT (DeLacy & Kennard, 1972) and its metabolites. The absence of Cl atoms at the terminal C atom, as well as the presence of Cl···Cl short contacts, might be responsible for this distortion compared with DDT and its congeners. Therefore, the unit-cell parameters of DDNU are also different. Comparative data for the unit-cell parameters of DDNU, DDMU, DDE and DDT are listed in Table 1. The C—C bond distances to the terminal C atom of DDNU are also different from those in DDT and its related compounds, as shown in Table 2.
In the crystal structure of DDNU, numerous intermolecular C—H···π interactions dominate in the crystal lattice and long Cl···Cl contacts are also observed. Additionally, there is a C25—H25···Cl2(x, y + 1, z) contact of 3.798 (3) Å, and with the C25—H25···Cl2 angle being 151°. These contacts may be characterized as weak electrostatic interactions rather than weak hydrogen bonds (Bats et al., 2001). A partial packing view of the crystal organization of DDNU showing C—H···π, C—H···Cl and weak Cl···Cl short contacts is presented in Fig. 2, and four distinct C—H···π interactions between the two independent molecules of DDNU in the asymmetric unit are tabulated in Table 3.
A Cl1···Cl2(x, y, z + 1) interaction of 3.4432 (13) Å in the symmetric [asymmetric?] units of two DDNU molecules is also observed. The intermolecular Cl···Cl short contact distance is less than the sum of the van der Waals radii (3.50 Å; Bondi, 1964). It has been reported (Gavezzotti & Filippini, 1993; Rowland & Taylor, 1996; Cox et al., 1997) in many halogen-containing crystal structures in the Cambridge Structural Database (CSD, Version?; Allen, 2002) that a significant number of Cl···Cl non-bonded contacts of less than 3.5 Å have been observed. It has been suggested (Pedireddi et al., 1994) that polarization and anisotropic electron distribution are important factors in the formation of these short contacts. This may be one of the reasons for the difference in the C—C bond length on the terminal C atom of the ethylene unit between DDE and DDNU. Successive Cl substituents at the terminal C atom appear to alter significantly the torsion angles between DDNU, DDMU and DDE, and their comparative data are compiled in Table 4.