Acta Cryst. (2012). E68, o62 [ doi:10.1107/S1600536811052044 ]
In the title compound, C18H18Cl2N2, the complete molecule is generated by the application of C2 symmetry. The C=N bond has an E configuration. The dihedral angle between the benzene ring and the 1,4-diazabutadiene plane is 66.81 (9)°.
Formic acid (0.5 ml) was added to a stirred solution of 2,3-butanedione (0.052 g, 0.6 mmol) and 3-chloro-2-methylaniline (0.0.170 g, 1.2 mmol) in methanol (20 ml). The mixture was refluxed for 24 h, then cooled and the precipitate was separated by filtration. The solid was recrystallized from dichloromethane/cyclohexane (v/v = 8:1), washed with cold ethanol and dried under vacuum to give the title ligand 0.18 g (90%). Anal. Calcd. for C18H18Cl2N2: C, 64.87; H, 5.44; N,8.41; Cl, 21.28. Found: C, 64.97; H, 5.33; N, 8.21; Cl, 21.59. Crystals suitable for X-ray structure determination were grown from a solution of the title compound in a mixture of cyclohexane/dichloromethane (1:2, v/v).
All hydrogen atoms were placed in calculated positions with C—H distances of 0.93 and 0.96 Å for aryl and methyl type H-atoms. They were included in the refinement in a riding model approximation, respectively. The H-atoms were assigned Uiso = 1.2 times Ueq of the aryl C atoms and 1.5 times Ueq of the methyl C atoms.
Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
![[Figure 1]](./bq2319fig1thm.gif)
| Fig. 1. Molecular structure of the title compound, using 30% probability level ellipsoids. Primed atoms are related by the symmetry code (-x + 1, -y + 1, -z). |
| C18H18Cl2N2 | F(000) = 348 |
| Mr = 333.24 | Dx = 1.294 Mg m−3 |
| Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -P 2yn | Cell parameters from 2237 reflections |
| a = 8.032 (6) Å | θ = 2.8–28.0° |
| b = 7.372 (5) Å | µ = 0.38 mm−1 |
| c = 14.475 (10) Å | T = 296 K |
| β = 93.533 (7)° | Block, colorless |
| V = 855.5 (11) Å3 | 0.23 × 0.21 × 0.19 mm |
| Z = 2 |
| Bruker APEXII CCD diffractometer | 1588 independent reflections |
| Radiation source: fine-focus sealed tube | 1199 reflections with I > 2σ(I) |
| graphite | Rint = 0.034 |
| φ and ω scans | θmax = 25.5°, θmin = 2.8° |
| Absorption correction: multi-scan (SADABS; Bruker, 2008) | h = −9→9 |
| Tmin = 0.918, Tmax = 0.932 | k = −8→8 |
| 5279 measured reflections | l = −17→17 |
| 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)] = 0.039 | Hydrogen site location: inferred from neighbouring sites |
| wR(F2) = 0.115 | H-atom parameters constrained |
| S = 1.06 | w = 1/[σ2(Fo2) + (0.0428P)2 + 0.4563P] where P = (Fo2 + 2Fc2)/3 |
| 1588 reflections | (Δ/σ)max = 0.001 |
| 102 parameters | Δρmax = 0.22 e Å−3 |
| 0 restraints | Δρmin = −0.28 e Å−3 |
| C18H18Cl2N2 | V = 855.5 (11) Å3 |
| Mr = 333.24 | Z = 2 |
| Monoclinic, P21/n | Mo Kα radiation |
| a = 8.032 (6) Å | µ = 0.38 mm−1 |
| b = 7.372 (5) Å | T = 296 K |
| c = 14.475 (10) Å | 0.23 × 0.21 × 0.19 mm |
| β = 93.533 (7)° |
| Bruker APEXII CCD diffractometer | 1588 independent reflections |
| Absorption correction: multi-scan (SADABS; Bruker, 2008) | 1199 reflections with I > 2σ(I) |
| Tmin = 0.918, Tmax = 0.932 | Rint = 0.034 |
| 5279 measured reflections | θmax = 25.5° |
| R[F2 > 2σ(F2)] = 0.039 | H-atom parameters constrained |
| wR(F2) = 0.115 | Δρmax = 0.22 e Å−3 |
| S = 1.06 | Δρmin = −0.28 e Å−3 |
| 1588 reflections | Absolute structure: ? |
| 102 parameters | Flack parameter: ? |
| 0 restraints | Rogers parameter: ? |
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. |
| x | y | z | Uiso*/Ueq | ||
| C1 | 0.4602 (2) | 0.2982 (3) | 0.17826 (13) | 0.0373 (5) | |
| C2 | 0.5314 (2) | 0.3432 (3) | 0.26633 (13) | 0.0382 (5) | |
| C3 | 0.5281 (3) | 0.2084 (3) | 0.33347 (14) | 0.0451 (5) | |
| C4 | 0.4584 (3) | 0.0403 (3) | 0.31793 (16) | 0.0532 (6) | |
| H4 | 0.4589 | −0.0453 | 0.3651 | 0.064* | |
| C5 | 0.3875 (3) | 0.0005 (3) | 0.23100 (16) | 0.0532 (6) | |
| H5 | 0.3391 | −0.1124 | 0.2192 | 0.064* | |
| C6 | 0.3887 (3) | 0.1286 (3) | 0.16168 (15) | 0.0469 (5) | |
| H6 | 0.3411 | 0.1013 | 0.1031 | 0.056* | |
| C7 | 0.6047 (3) | 0.5274 (3) | 0.28511 (17) | 0.0603 (7) | |
| H7A | 0.5640 | 0.5748 | 0.3412 | 0.090* | |
| H7B | 0.5730 | 0.6070 | 0.2346 | 0.090* | |
| H7C | 0.7241 | 0.5182 | 0.2916 | 0.090* | |
| C8 | 0.5174 (2) | 0.4244 (3) | 0.03386 (13) | 0.0383 (5) | |
| C9 | 0.6332 (4) | 0.2775 (3) | 0.00740 (18) | 0.0672 (8) | |
| H9A | 0.6605 | 0.2017 | 0.0601 | 0.101* | |
| H9B | 0.7334 | 0.3304 | −0.0136 | 0.101* | |
| H9C | 0.5803 | 0.2058 | −0.0414 | 0.101* | |
| Cl1 | 0.61699 (10) | 0.25335 (11) | 0.44457 (4) | 0.0788 (3) | |
| N1 | 0.4462 (2) | 0.4357 (2) | 0.10980 (11) | 0.0421 (4) |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| C1 | 0.0400 (11) | 0.0413 (12) | 0.0309 (10) | 0.0048 (9) | 0.0052 (8) | 0.0042 (8) |
| C2 | 0.0360 (10) | 0.0453 (12) | 0.0334 (11) | 0.0021 (9) | 0.0046 (8) | 0.0013 (9) |
| C3 | 0.0424 (12) | 0.0634 (15) | 0.0295 (11) | 0.0035 (10) | 0.0009 (8) | 0.0075 (10) |
| C4 | 0.0594 (14) | 0.0556 (15) | 0.0455 (13) | −0.0024 (12) | 0.0089 (11) | 0.0188 (11) |
| C5 | 0.0584 (14) | 0.0491 (14) | 0.0527 (14) | −0.0101 (11) | 0.0075 (11) | 0.0077 (11) |
| C6 | 0.0527 (13) | 0.0505 (14) | 0.0370 (12) | −0.0034 (10) | 0.0001 (9) | −0.0003 (10) |
| C7 | 0.0726 (17) | 0.0586 (16) | 0.0487 (14) | −0.0108 (13) | −0.0031 (12) | −0.0026 (12) |
| C8 | 0.0443 (11) | 0.0404 (11) | 0.0299 (10) | 0.0026 (9) | −0.0003 (8) | 0.0024 (9) |
| C9 | 0.0875 (19) | 0.0616 (16) | 0.0553 (15) | 0.0312 (14) | 0.0260 (14) | 0.0189 (13) |
| Cl1 | 0.0917 (6) | 0.1055 (6) | 0.0367 (4) | −0.0069 (4) | −0.0154 (3) | 0.0111 (3) |
| N1 | 0.0523 (11) | 0.0433 (10) | 0.0308 (9) | 0.0050 (8) | 0.0021 (7) | 0.0058 (8) |
| C1—C6 | 1.391 (3) | C6—H6 | 0.9300 |
| C1—C2 | 1.404 (3) | C7—H7A | 0.9600 |
| C1—N1 | 1.417 (3) | C7—H7B | 0.9600 |
| C2—C3 | 1.392 (3) | C7—H7C | 0.9600 |
| C2—C7 | 1.498 (3) | C8—N1 | 1.273 (3) |
| C3—C4 | 1.373 (3) | C8—C9 | 1.493 (3) |
| C3—Cl1 | 1.751 (2) | C8—C8i | 1.500 (4) |
| C4—C5 | 1.380 (3) | C9—H9A | 0.9600 |
| C4—H4 | 0.9300 | C9—H9B | 0.9600 |
| C5—C6 | 1.378 (3) | C9—H9C | 0.9600 |
| C5—H5 | 0.9300 | ||
| C6—C1—C2 | 120.64 (19) | C1—C6—H6 | 119.6 |
| C6—C1—N1 | 120.53 (18) | C2—C7—H7A | 109.5 |
| C2—C1—N1 | 118.46 (19) | C2—C7—H7B | 109.5 |
| C3—C2—C1 | 116.2 (2) | H7A—C7—H7B | 109.5 |
| C3—C2—C7 | 123.0 (2) | C2—C7—H7C | 109.5 |
| C1—C2—C7 | 120.82 (19) | H7A—C7—H7C | 109.5 |
| C4—C3—C2 | 123.8 (2) | H7B—C7—H7C | 109.5 |
| C4—C3—Cl1 | 117.42 (17) | N1—C8—C9 | 126.12 (19) |
| C2—C3—Cl1 | 118.82 (18) | N1—C8—C8i | 116.1 (2) |
| C3—C4—C5 | 118.8 (2) | C9—C8—C8i | 117.8 (2) |
| C3—C4—H4 | 120.6 | C8—C9—H9A | 109.5 |
| C5—C4—H4 | 120.6 | C8—C9—H9B | 109.5 |
| C6—C5—C4 | 119.8 (2) | H9A—C9—H9B | 109.5 |
| C6—C5—H5 | 120.1 | C8—C9—H9C | 109.5 |
| C4—C5—H5 | 120.1 | H9A—C9—H9C | 109.5 |
| C5—C6—C1 | 120.8 (2) | H9B—C9—H9C | 109.5 |
| C5—C6—H6 | 119.6 | C8—N1—C1 | 122.45 (18) |
| C6—C1—C2—C3 | 1.1 (3) | Cl1—C3—C4—C5 | −179.88 (18) |
| N1—C1—C2—C3 | 174.16 (17) | C3—C4—C5—C6 | 0.4 (3) |
| C6—C1—C2—C7 | −178.5 (2) | C4—C5—C6—C1 | −0.2 (3) |
| N1—C1—C2—C7 | −5.4 (3) | C2—C1—C6—C5 | −0.6 (3) |
| C1—C2—C3—C4 | −0.9 (3) | N1—C1—C6—C5 | −173.5 (2) |
| C7—C2—C3—C4 | 178.6 (2) | C9—C8—N1—C1 | −4.5 (3) |
| C1—C2—C3—Cl1 | 179.13 (14) | C8i—C8—N1—C1 | 176.6 (2) |
| C7—C2—C3—Cl1 | −1.3 (3) | C6—C1—N1—C8 | −67.6 (3) |
| C2—C3—C4—C5 | 0.2 (4) | C2—C1—N1—C8 | 119.4 (2) |
| Symmetry codes: (i) −x+1, −y+1, −z. |
We thank the National Natural Science Foundation of China (20964003) for funding. We also thank the Key Laboratory of Eco Environment-Related Polymer Materials of Ministry of Education, Key Laboratory of Polymer Materials of Gansu Province (Northwest Normal University), for financial support
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There is a considerable interest in the development of new late transition metal catalysts for the polymerization of α-olefins since Brookhart discovered highly active α-diimine nickel catalysts (Johnson et al., 1995; Killian et al., 1996). It is well known that the ligand structure had significant influence on the product properties and polymerization activities (Popeney & Guan, 2010; Popeney et al., 2011; Yuan et al., 2005). In this study, we designed and synthesized the title compound as a bidentate ligand, and its molecular structure was characterized by X-ray diffraction. In the solid state, the ligand exhibits a C2 symmetry. The single bond of 1,4-diazabutadiene fragment is (E)-configured. The dihedral angle between the benzene ring and 1,4-diazabutadiene plane is 66.81 (9)°. (Figure 1.) In the crystal packing, there is no hydrogen-bond between the ligand molecules.