(Z)-3-Chloro-N-[(Z)-3-(3-chloro-2-methyl­phenyl­imino)­butan-2-yl­­idene]-2-methyl­aniline

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)°.

Related literature

For background to the applications of the olefin polymerization Ni(II)-α-diimine catalysts, see: Johnson et al. (1995); Killian et al. (1996). For the effect of the ligand structure on the activity of the catalyst and properties of the products, see: Popeney & Guan (2010); Popeney et al. (2011); Yuan et al. (2005). For related structures, see: Kose & McKee (2011); Wei et al. (2011).

Experimental

Crystal data

• C₁₈H₁₈Cl₂N₂

• M_r = 333.24

• Monoclinic, P 2₁ /n

• a = 8.032 (6) Å

• b = 7.372 (5) Å

• c = 14.475 (10) Å

• β = 93.533 (7)°

• V = 855.5 (11) ų

• Z = 2

• Mo Kα radiation

• μ = 0.38 mm⁻¹

• T = 296 K

• 0.23 × 0.21 × 0.19 mm

Data collection

• Bruker APEXII CCD diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2008) T_min = 0.918, T_max = 0.932

• 5279 measured reflections

• 1588 independent reflections

• 1199 reflections with I > 2σ(I)

• R_int = 0.034

Refinement

• R[F² > 2σ(F²)] = 0.039

• wR(F²) = 0.115

• S = 1.06

• 1588 reflections

• 102 parameters

• H-atom parameters constrained

• Δρ_max = 0.22 e Å⁻³

• Δρ_min = −0.28 e Å⁻³

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT; 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.

Supporting information

S1. Comment

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.

Related literature

For background to the applications of the olefin polymerization Ni(II)-α-diimine catalysts, see: Johnson et al. (1995); Killian et al. (1996). For the effect of the ligand structure on the activity of the catalyst and properties of the products, see: Popeney & Guan (2010); Popeney et al. (2011); Yuan et al. (2005). For related structures, see: Kose & McKee (2011); Wei et al. (2011).

S2. Experimental

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).

S3. Refinement

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.

Computing details

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).

Figures

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).

(Z)-3-Chloro-N-[(Z)-3-(3-chloro-2-methylphenylimino)butan- 2-ylidene]-2-methylaniline

Crystal data

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) Å^3	0.23 × 0.21 × 0.19 mm
Z = 2

Data collection

Bruker APEXII CCD diffractometer	1588 independent reflections
Radiation source: fine-focus sealed tube	1199 reflections with I > 2σ(I)
Graphite monochromator	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

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.115	H-atom parameters constrained
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0428P)^2 + 0.4563P] where P = (Fo^2 + 2Fc^2)/3
1588 reflections	(Δ/σ)max = 0.001
102 parameters	Δρmax = 0.22 e Å^−3
0 restraints	Δρmin = −0.28 e Å^−3

Special details

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 (Ų)

	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)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
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)

Geometric parameters (Å, º)

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—C8^i	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—C8^i	116.1 (2)
C3—C4—C5	118.8 (2)	C9—C8—C8^i	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)	C8^i—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 code: (i) −x+1, −y+1, −z.