supplementary materials


cv5204 scheme

Acta Cryst. (2012). E68, o164    [ doi:10.1107/S1600536811053244 ]

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

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

Abstract top

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)°.

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).

Refinement top

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, respectively. They were included in the refinement in a riding model approximation, with Uiso = 1.2-1.5 Ueq(C).

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
[Figure 1] 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
C20H24N2Dx = 1.135 Mg m3
Mr = 292.41Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, PbcaCell parameters from 1144 reflections
a = 13.50 (1) Åθ = 2.9–23.2°
b = 7.571 (6) ŵ = 0.07 mm1
c = 16.738 (12) ÅT = 296 K
V = 1711 (2) Å3Block, yellow
Z = 40.23 × 0.20 × 0.14 mm
F(000) = 632
Data collection top
Bruker APEXII CCD
diffractometer
1592 independent reflections
Radiation source: fine-focus sealed tube1043 reflections with I > 2σ(I)
graphiteRint = 0.031
φ and ω scansθmax = 25.5°, θmin = 2.4°
Absorption correction: multi-scan
(SADABS; Bruker, 2008)
h = 816
Tmin = 0.985, Tmax = 0.991k = 69
5143 measured reflectionsl = 1620
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.052H-atom parameters constrained
wR(F2) = 0.175 w = 1/[σ2(Fo2) + (0.0962P)2 + 0.2091P]
where P = (Fo2 + 2Fc2)/3
S = 1.05(Δ/σ)max < 0.001
1592 reflectionsΔρmax = 0.21 e Å3
104 parametersΔρmin = 0.15 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.009 (4)
Crystal data top
C20H24N2V = 1711 (2) Å3
Mr = 292.41Z = 4
Orthorhombic, PbcaMo Kα radiation
a = 13.50 (1) ŵ = 0.07 mm1
b = 7.571 (6) ÅT = 296 K
c = 16.738 (12) Å0.23 × 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)
Tmin = 0.985, Tmax = 0.991Rint = 0.031
5143 measured reflectionsθmax = 25.5°
Refinement top
R[F2 > 2σ(F2)] = 0.052H-atom parameters constrained
wR(F2) = 0.175Δρmax = 0.21 e Å3
S = 1.05Δρmin = 0.15 e Å3
1592 reflectionsAbsolute structure: ?
104 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
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
xyzUiso*/Ueq
C10.60082 (15)0.9674 (3)0.65918 (13)0.0471 (6)
C20.69975 (15)0.9165 (3)0.66744 (13)0.0464 (6)
C30.72926 (16)0.8473 (3)0.74028 (13)0.0528 (6)
H30.79460.81040.74600.063*
C40.66613 (18)0.8305 (3)0.80502 (13)0.0548 (6)
C50.56961 (18)0.8859 (3)0.79551 (14)0.0596 (7)
H50.52570.87820.83820.072*
C60.53728 (17)0.9527 (3)0.72328 (15)0.0579 (7)
H60.47170.98820.71780.070*
C70.77174 (18)0.9360 (3)0.59996 (15)0.0669 (8)
H7A0.74030.90260.55080.100*
H7B0.82800.86120.60920.100*
H7C0.79311.05670.59660.100*
C80.7013 (2)0.7515 (4)0.88279 (14)0.0795 (9)
H8A0.76420.69510.87470.119*
H8B0.65400.66590.90110.119*
H8C0.70810.84320.92200.119*
C90.51658 (15)0.9537 (3)0.53705 (12)0.0467 (6)
C100.48786 (19)0.7641 (3)0.54753 (15)0.0662 (7)
H10A0.51910.71770.59460.099*
H10B0.50880.69760.50170.099*
H10C0.41720.75550.55300.099*
N10.56812 (12)1.0428 (2)0.58600 (11)0.0516 (6)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0501 (13)0.0426 (12)0.0487 (13)0.0029 (9)0.0084 (10)0.0010 (10)
C20.0488 (13)0.0429 (12)0.0476 (13)0.0017 (9)0.0048 (9)0.0027 (10)
C30.0475 (12)0.0526 (13)0.0583 (14)0.0050 (10)0.0116 (10)0.0000 (11)
C40.0658 (15)0.0504 (14)0.0483 (14)0.0026 (12)0.0108 (11)0.0014 (11)
C50.0630 (15)0.0636 (16)0.0523 (14)0.0035 (12)0.0046 (11)0.0049 (12)
C60.0482 (12)0.0610 (16)0.0646 (15)0.0054 (11)0.0008 (11)0.0083 (12)
C70.0624 (15)0.0685 (17)0.0697 (16)0.0067 (12)0.0087 (12)0.0054 (13)
C80.0911 (19)0.089 (2)0.0584 (16)0.0039 (15)0.0191 (14)0.0118 (15)
C90.0401 (11)0.0499 (14)0.0501 (13)0.0004 (9)0.0031 (9)0.0045 (10)
C100.0783 (17)0.0551 (15)0.0652 (16)0.0118 (12)0.0161 (12)0.0118 (12)
N10.0503 (11)0.0505 (11)0.0540 (12)0.0017 (8)0.0086 (9)0.0083 (9)
Geometric parameters (Å, °) top
C1—C61.378 (3)C7—H7A0.9600
C1—C21.397 (3)C7—H7B0.9600
C1—N11.421 (3)C7—H7C0.9600
C2—C31.385 (3)C8—H8A0.9600
C2—C71.497 (3)C8—H8B0.9600
C3—C41.384 (3)C8—H8C0.9600
C3—H30.9300C9—N11.269 (3)
C4—C51.378 (3)C9—C9i1.494 (4)
C4—C81.509 (3)C9—C101.497 (3)
C5—C61.381 (3)C10—H10A0.9600
C5—H50.9300C10—H10B0.9600
C6—H60.9300C10—H10C0.9600
C6—C1—C2119.7 (2)H7A—C7—H7B109.5
C6—C1—N1120.67 (19)C2—C7—H7C109.5
C2—C1—N1119.5 (2)H7A—C7—H7C109.5
C3—C2—C1117.8 (2)H7B—C7—H7C109.5
C3—C2—C7121.0 (2)C4—C8—H8A109.5
C1—C2—C7121.2 (2)C4—C8—H8B109.5
C4—C3—C2123.1 (2)H8A—C8—H8B109.5
C4—C3—H3118.4C4—C8—H8C109.5
C2—C3—H3118.4H8A—C8—H8C109.5
C5—C4—C3117.6 (2)H8B—C8—H8C109.5
C5—C4—C8121.2 (2)N1—C9—C9i116.8 (2)
C3—C4—C8121.2 (2)N1—C9—C10125.18 (19)
C4—C5—C6120.7 (2)C9i—C9—C10118.0 (2)
C4—C5—H5119.6C9—C10—H10A109.5
C6—C5—H5119.6C9—C10—H10B109.5
C1—C6—C5121.0 (2)H10A—C10—H10B109.5
C1—C6—H6119.5C9—C10—H10C109.5
C5—C6—H6119.5H10A—C10—H10C109.5
C2—C7—H7A109.5H10B—C10—H10C109.5
C2—C7—H7B109.5C9—N1—C1120.87 (19)
C6—C1—C2—C31.9 (3)C8—C4—C5—C6177.9 (2)
N1—C1—C2—C3178.55 (19)C2—C1—C6—C50.9 (4)
C6—C1—C2—C7178.0 (2)N1—C1—C6—C5177.5 (2)
N1—C1—C2—C71.4 (3)C4—C5—C6—C10.7 (4)
C1—C2—C3—C41.5 (3)C9i—C9—N1—C1178.3 (2)
C7—C2—C3—C4178.4 (2)C10—C9—N1—C12.4 (3)
C2—C3—C4—C50.0 (3)C6—C1—N1—C978.8 (3)
C2—C3—C4—C8179.0 (2)C2—C1—N1—C9104.6 (2)
C3—C4—C5—C61.1 (4)
Symmetry codes: (i) −x+1, −y+2, −z+1.
Acknowledgements top

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.

references
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