(Z)-N-[(Z)-3-(2,4-Dimethyl­phenyl­imino)­butan-2-yl­idene]-2,4-dimethyl­aniline

Yuan, J.; Miao, C.; Xu, W.; Yuan, B.

doi:10.1107/S1600536811053244

organic compounds

CRYSTALLOGRAPHIC
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ISSN: 2056-9890

Volume 68| Part 1| January 2012| Page o164

doi:10.1107/S1600536811053244

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(Z)-N-[(Z)-3-(2,4-Dimethylphenylimino)butan-2-ylidene]-2,4-dimethylaniline

Jianchao Yuan,^a ^* Chengping Miao,^a Weibing Xu ^a and Bingnian Yuan ^a

^aKey Laboratory of Eco-Environment-Related Polymer Materials of the Ministry of Education, Key Laboratory of Polymer Materials of Gansu Province, College of Chemistry & Chemical Engineering, Northwest Normal University, Lanzhou 730070, People's Republic of China
^*Correspondence e-mail: jianchaoyuan@nwnu.edu.cn

(Received 15 November 2011; accepted 10 December 2011; online 17 December 2011)

The asymmetric unit of the title compound, C₂₀H₂₄N₂, contains one half -molecule which exhibits a crystallographically imposed center of symmetry. The benzene rings are inclined to the 1,4-diazabutadiene mean plane by 78.3 (2)°.

Related literature

The title compound was synthesized as a α-diimine ligand for Ni^II-α-diimine olefin polymerization catalysts. For applications of α-diimine ligands, see: Johnson et al. (1995 ); Killian et al. (1996 ). For the design and synthesis of new α-diimine derivatives, see: Yuan et al. (2005 ); Popeney & Guan (2005 , 2010 ); Popeney et al. (2011 ). The crystal structures of Re and Ni complexes with the title ligand were reported by Kia et al. (2005 ) and Yuan et al. (2011 ), respectively.

Experimental

Crystal data

C₂₀H₂₄N₂
M_r = 292.41
Orthorhombic, P b c a
a = 13.50 (1) Å
b = 7.571 (6) Å
c = 16.738 (12) Å
V = 1711 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 296 K
0.23 × 0.20 × 0.14 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ) T_min = 0.985, T_max = 0.991
5143 measured reflections
1592 independent reflections
1043 reflections with I > 2σ(I)
R_int = 0.031

Refinement

R[F² > 2σ(F²)] = 0.052
wR(F²) = 0.175
S = 1.05
1592 reflections
104 parameters
H-atom parameters constrained
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.15 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

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811053244/cv5204sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811053244/cv5204Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536811053244/cv5204Isup3.cml

checkCIF report

Comment top

α-Diimine ligand nickel catalysts greatly attracted attention due to their high catalytic activity in ethylene polymerization (Johnson et al., 1995; Killian et al., 1996). Design and synthesis of the ligands is crucial (Popeney et al., 2005, 2010, 2011; Yuan et al., 2005). Herewith we present the title compound (I).

In (I) (Fig. 1), the single C—C bond in 1,4-diazabutadiene fragment is trans-configured and situated on inversion center. The dihedral angle between the benzene ring and 1,4-diazabutadiene plane is 78.3 (2)°. However, the trans-configured ligand can be transformed into cis-configured ligand in order to facilitate the formation of α-diimine-metal complexes, for examples, see Yuan et al. (2011) for Ni complex, and Kia et al. (2005) for Re complex.

Related literature top

For applications of α-diimine ligands, see: Johnson et al. (1995); Killian et al. (1996). For the design and synthesis of new α-diimine derivatives, see: Yuan et al. (2005); Popeney & Guan (2005, 2010); Popeney et al. (2011). The crystal structures of Re and Ni complexes with the title ligand were reported by Kia et al. (2005) and Yuan et al. (2011), respectively.

Experimental top

Formic acid (1 ml) was added to a stirred solution of 2,3-butanedione (0.052 g, 0.6 mmol) and 2,4-dimethylaniline (0.144 g, 1.2 mmol) in methanol (30 ml). The mixture was refluxed for 24 h, then cooled and the precipitate was separated by filtration. The solid was recrystallized from ethanol/dichloromethane (v/v = 8:1), washed and dried under vacuum. Yield: 0.160 g (82%). 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).

Computing details top

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 top

Fig. 1. The molecular structure of the title compound, with the atom-labelling scheme [symmetry code: (a) 1 - x, 2 - y, 1 - z]. Displacement ellipsoids are shown at the 30% probability level.

(Z)-N-[(Z)-3-(2,4-Dimethylphenylimino)butan-2-ylidene]- 2,4-dimethylaniline top

Crystal data top

C₂₀H₂₄N₂	D_x = 1.135 Mg m⁻³
M_r = 292.41	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pbca	Cell parameters from 1144 reflections
a = 13.50 (1) Å	θ = 2.9–23.2°
b = 7.571 (6) Å	µ = 0.07 mm⁻¹
c = 16.738 (12) Å	T = 296 K
V = 1711 (2) Å³	Block, yellow
Z = 4	0.23 × 0.20 × 0.14 mm
F(000) = 632

Data collection top

Bruker APEXII CCD diffractometer	1592 independent reflections
Radiation source: fine-focus sealed tube	1043 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.031
ϕ and ω scans	θ_max = 25.5°, θ_min = 2.4°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −8→16
T_min = 0.985, T_max = 0.991	k = −6→9
5143 measured reflections	l = −16→20

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.052	H-atom parameters constrained
wR(F²) = 0.175	w = 1/[σ²(F_o²) + (0.0962P)² + 0.2091P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max < 0.001
1592 reflections	Δρ_max = 0.21 e Å⁻³
104 parameters	Δρ_min = −0.15 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.009 (4)

Crystal data top

C₂₀H₂₄N₂	V = 1711 (2) Å³
M_r = 292.41	Z = 4
Orthorhombic, Pbca	Mo Kα radiation
a = 13.50 (1) Å	µ = 0.07 mm⁻¹
b = 7.571 (6) Å	T = 296 K
c = 16.738 (12) Å	0.23 × 0.20 × 0.14 mm

Data collection top

Bruker APEXII CCD diffractometer	1592 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2008)	1043 reflections with I > 2σ(I)
T_min = 0.985, T_max = 0.991	R_int = 0.031
5143 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.052	0 restraints
wR(F²) = 0.175	H-atom parameters constrained
S = 1.05	Δρ_max = 0.21 e Å⁻³
1592 reflections	Δρ_min = −0.15 e Å⁻³
104 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	U_iso*/U_eq
C1	0.60082 (15)	0.9674 (3)	0.65918 (13)	0.0471 (6)
C2	0.69975 (15)	0.9165 (3)	0.66744 (13)	0.0464 (6)
C3	0.72926 (16)	0.8473 (3)	0.74028 (13)	0.0528 (6)
H3	0.7946	0.8104	0.7460	0.063*
C4	0.66613 (18)	0.8305 (3)	0.80502 (13)	0.0548 (6)
C5	0.56961 (18)	0.8859 (3)	0.79551 (14)	0.0596 (7)
H5	0.5257	0.8782	0.8382	0.072*
C6	0.53728 (17)	0.9527 (3)	0.72328 (15)	0.0579 (7)
H6	0.4717	0.9882	0.7178	0.070*
C7	0.77174 (18)	0.9360 (3)	0.59996 (15)	0.0669 (8)
H7A	0.7403	0.9026	0.5508	0.100*
H7B	0.8280	0.8612	0.6092	0.100*
H7C	0.7931	1.0567	0.5966	0.100*
C8	0.7013 (2)	0.7515 (4)	0.88279 (14)	0.0795 (9)
H8A	0.7642	0.6951	0.8747	0.119*
H8B	0.6540	0.6659	0.9011	0.119*
H8C	0.7081	0.8432	0.9220	0.119*
C9	0.51658 (15)	0.9537 (3)	0.53705 (12)	0.0467 (6)
C10	0.48786 (19)	0.7641 (3)	0.54753 (15)	0.0662 (7)
H10A	0.5191	0.7177	0.5946	0.099*
H10B	0.5088	0.6976	0.5017	0.099*
H10C	0.4172	0.7555	0.5530	0.099*
N1	0.56812 (12)	1.0428 (2)	0.58600 (11)	0.0516 (6)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0501 (13)	0.0426 (12)	0.0487 (13)	−0.0029 (9)	−0.0084 (10)	0.0010 (10)
C2	0.0488 (13)	0.0429 (12)	0.0476 (13)	0.0017 (9)	−0.0048 (9)	−0.0027 (10)
C3	0.0475 (12)	0.0526 (13)	0.0583 (14)	0.0050 (10)	−0.0116 (10)	0.0000 (11)
C4	0.0658 (15)	0.0504 (14)	0.0483 (14)	−0.0026 (12)	−0.0108 (11)	0.0014 (11)
C5	0.0630 (15)	0.0636 (16)	0.0523 (14)	0.0035 (12)	0.0046 (11)	0.0049 (12)
C6	0.0482 (12)	0.0610 (16)	0.0646 (15)	0.0054 (11)	−0.0008 (11)	0.0083 (12)
C7	0.0624 (15)	0.0685 (17)	0.0697 (16)	0.0067 (12)	0.0087 (12)	0.0054 (13)
C8	0.0911 (19)	0.089 (2)	0.0584 (16)	−0.0039 (15)	−0.0191 (14)	0.0118 (15)
C9	0.0401 (11)	0.0499 (14)	0.0501 (13)	0.0004 (9)	−0.0031 (9)	0.0045 (10)
C10	0.0783 (17)	0.0551 (15)	0.0652 (16)	−0.0118 (12)	−0.0161 (12)	0.0118 (12)
N1	0.0503 (11)	0.0505 (11)	0.0540 (12)	−0.0017 (8)	−0.0086 (9)	0.0083 (9)

Geometric parameters (Å, º) top

C1—C6	1.378 (3)	C7—H7A	0.9600
C1—C2	1.397 (3)	C7—H7B	0.9600
C1—N1	1.421 (3)	C7—H7C	0.9600
C2—C3	1.385 (3)	C8—H8A	0.9600
C2—C7	1.497 (3)	C8—H8B	0.9600
C3—C4	1.384 (3)	C8—H8C	0.9600
C3—H3	0.9300	C9—N1	1.269 (3)
C4—C5	1.378 (3)	C9—C9ⁱ	1.494 (4)
C4—C8	1.509 (3)	C9—C10	1.497 (3)
C5—C6	1.381 (3)	C10—H10A	0.9600
C5—H5	0.9300	C10—H10B	0.9600
C6—H6	0.9300	C10—H10C	0.9600

C6—C1—C2	119.7 (2)	H7A—C7—H7B	109.5
C6—C1—N1	120.67 (19)	C2—C7—H7C	109.5
C2—C1—N1	119.5 (2)	H7A—C7—H7C	109.5
C3—C2—C1	117.8 (2)	H7B—C7—H7C	109.5
C3—C2—C7	121.0 (2)	C4—C8—H8A	109.5
C1—C2—C7	121.2 (2)	C4—C8—H8B	109.5
C4—C3—C2	123.1 (2)	H8A—C8—H8B	109.5
C4—C3—H3	118.4	C4—C8—H8C	109.5
C2—C3—H3	118.4	H8A—C8—H8C	109.5
C5—C4—C3	117.6 (2)	H8B—C8—H8C	109.5
C5—C4—C8	121.2 (2)	N1—C9—C9ⁱ	116.8 (2)
C3—C4—C8	121.2 (2)	N1—C9—C10	125.18 (19)
C4—C5—C6	120.7 (2)	C9ⁱ—C9—C10	118.0 (2)
C4—C5—H5	119.6	C9—C10—H10A	109.5
C6—C5—H5	119.6	C9—C10—H10B	109.5
C1—C6—C5	121.0 (2)	H10A—C10—H10B	109.5
C1—C6—H6	119.5	C9—C10—H10C	109.5
C5—C6—H6	119.5	H10A—C10—H10C	109.5
C2—C7—H7A	109.5	H10B—C10—H10C	109.5
C2—C7—H7B	109.5	C9—N1—C1	120.87 (19)

C6—C1—C2—C3	1.9 (3)	C8—C4—C5—C6	−177.9 (2)
N1—C1—C2—C3	178.55 (19)	C2—C1—C6—C5	−0.9 (4)
C6—C1—C2—C7	−178.0 (2)	N1—C1—C6—C5	−177.5 (2)
N1—C1—C2—C7	−1.4 (3)	C4—C5—C6—C1	−0.7 (4)
C1—C2—C3—C4	−1.5 (3)	C9ⁱ—C9—N1—C1	178.3 (2)
C7—C2—C3—C4	178.4 (2)	C10—C9—N1—C1	−2.4 (3)
C2—C3—C4—C5	0.0 (3)	C6—C1—N1—C9	−78.8 (3)
C2—C3—C4—C8	179.0 (2)	C2—C1—N1—C9	104.6 (2)
C3—C4—C5—C6	1.1 (4)

Symmetry code: (i) −x+1, −y+2, −z+1.

Experimental details

Crystal data
Chemical formula	C₂₀H₂₄N₂
M_r	292.41
Crystal system, space group	Orthorhombic, Pbca
Temperature (K)	296
a, b, c (Å)	13.50 (1), 7.571 (6), 16.738 (12)
V (Å³)	1711 (2)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.07
Crystal size (mm)	0.23 × 0.20 × 0.14

Data collection
Diffractometer	Bruker APEXII CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2008)
T_min, T_max	0.985, 0.991
No. of measured, independent and observed [I > 2σ(I)] reflections	5143, 1592, 1043
R_int	0.031
(sin θ/λ)_max (Å⁻¹)	0.606

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.052, 0.175, 1.05
No. of reflections	1592
No. of parameters	104
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.21, −0.15

Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Acknowledgements

We thank the National Natural Science Foundation of China (grant No. 20964003) for funding. We also thank the Key Laboratory of Eco Environment-Related Polymer Materials of the Ministry of Education and Key Laboratory of Polymer Materials of Gansu Province (Northwest Normal University) for financial support.

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