(Z)-4-Bromo-N-{(Z)-3-[(4-bromo-2,6-diisopropyl­phen­yl)imino]­butan-2-yl­idene}-2,6-diisopropyl­aniline

Zhang, C.; Wu, G.-F.; Huang, B.-M.; Lu, X.-Q.

doi:10.1107/S160053681205194X

organic compounds

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ISSN: 2056-9890

Volume 69| Part 2| February 2013| Page o216

doi:10.1107/S160053681205194X

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(Z)-4-Bromo-N-{(Z)-3-[(4-bromo-2,6-diisopropylphenyl)imino]butan-2-ylidene}-2,6-diisopropylaniline

Cun Zhang,^a Guo-Fan Wu,^a Bao-Mei Huang ^a and Xiao-Quan Lu ^a ^*

^aKey Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Chemistry & Chemical Engineering, Northwest Normal University, Lanzhou 730070, People's Republic of China
^*Correspondence e-mail: luxq@nwnu.edu.cn

(Received 11 December 2012; accepted 27 December 2012; online 9 January 2013)

The title compound, C₂₈H₃₈Br₂N₂, is centrosymmetric with the mid-point of the central C—C bond of the butyl group located on an inversion center. The terminal benzene ring is approximately perpendicular to the central 1,4-diazabutadiene mean plane [dihedral angle = 78.23 (3)°]. No hydrogen bonding or aromatic stacking is observed in the crystal structure.

Related literature

For applications of diimine catalysts, see: Cotts et al. (2000 ); Ittel et al. (2000 ); Johnson et al. (1995 ); Zhang & Ye (2012 ).

Experimental

Crystal data

C₂₈H₃₈Br₂N₂
M_r = 562.42
Monoclinic, P 2₁ /n
a = 9.099 (3) Å
b = 12.199 (4) Å
c = 13.566 (5) Å
β = 104.905 (5)°
V = 1455.2 (9) Å³
Z = 2
Mo Kα radiation
μ = 2.80 mm⁻¹
T = 296 K
0.25 × 0.23 × 0.19 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2001 ) T_min = 0.541, T_max = 0.618
7266 measured reflections
2685 independent reflections
1460 reflections with I > 2σ(I)
R_int = 0.043

Refinement

R[F² > 2σ(F²)] = 0.052
wR(F²) = 0.179
S = 0.94
2685 reflections
150 parameters
84 restraints
H-atom parameters constrained
Δρ_max = 0.46 e Å⁻³
Δρ_min = −0.40 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053681205194X/xu5664sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053681205194X/xu5664Isup2.hkl

Supporting information file. DOI: 10.1107/S160053681205194X/xu5664Isup3.cml

checkCIF report

Comment top

In recent years, Ni(II)/Pd(II)-α-diimine catalysts were greatly attracted attention due to their high catalytic activity and influence on product performance in olefin polymerization (Zhang & Ye, 2012; Johnson et al., 1995). It is well known that the polymerization conditions (such as the reaction olefin pressure, temperature etc.) and ligand structure had a great impact on catalytic activity and polymer properties (Cotts et al., 2000; Ittel et al., 2000).

In the solid state, the structure exhibits trans-conformation about the central C—C bond of the ligand backbone. Bond lengths and angles are within the expected range for α-diimines. The dihedral angle between the aryl ring and 1,4-diazabutadiene plane is 78.23 (3)°(Fig. 1). In the crystal packing, there is no hydrogen-bond between the molecules.

Related literature top

For applications of diimine catalysts, see: Cotts et al. (2000); Ittel et al. (2000); Johnson et al. (1995); Zhang & Ye (2012).

Experimental top

Formic acid (0.5 ml) was added to a stirred solution of 2,3-butanedione (0.042 g, 0.49 mmol) and 4-Bromo-2,6-diisopropyl-phenylamine (0.250 g, 0.98 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 0.21 g (75%). Anal. Calcd. for C₂₈H₃₈Br₂N₂: C, 59.79; H, 6.81; N,4.98; Found: C, 60.29; H, 6.95; N, 4.74.

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

Fig. 1. Molecular structure of the title compound, using 30% probability level ellipsoids.

(Z)-4-Bromo-N-{(Z)-3-[(4-bromo-2,6- diisopropylphenyl)imino]butan-2-ylidene}-2,6-diisopropylaniline top

Crystal data top

C₂₈H₃₈Br₂N₂	F(000) = 580
M_r = 562.42	D_x = 1.284 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1370 reflections
a = 9.099 (3) Å	θ = 2.9–21.4°
b = 12.199 (4) Å	µ = 2.80 mm⁻¹
c = 13.566 (5) Å	T = 296 K
β = 104.905 (5)°	Block, yellow
V = 1455.2 (9) Å³	0.25 × 0.23 × 0.19 mm
Z = 2

Data collection top

Bruker APEXII CCD diffractometer	2685 independent reflections
Radiation source: fine-focus sealed tube	1460 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.043
ϕ and ω scans	θ_max = 25.5°, θ_min = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −10→10
T_min = 0.541, T_max = 0.618	k = −12→14
7266 measured reflections	l = −16→14

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)] = 0.052	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.179	H-atom parameters constrained
S = 0.94	w = 1/[σ²(F_o²) + (0.1P)² + 0.7029P] where P = (F_o² + 2F_c²)/3
2685 reflections	(Δ/σ)_max < 0.001
150 parameters	Δρ_max = 0.46 e Å⁻³
84 restraints	Δρ_min = −0.40 e Å⁻³

Crystal data top

C₂₈H₃₈Br₂N₂	V = 1455.2 (9) Å³
M_r = 562.42	Z = 2
Monoclinic, P2₁/n	Mo Kα radiation
a = 9.099 (3) Å	µ = 2.80 mm⁻¹
b = 12.199 (4) Å	T = 296 K
c = 13.566 (5) Å	0.25 × 0.23 × 0.19 mm
β = 104.905 (5)°

Data collection top

Bruker APEXII CCD diffractometer	2685 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2001)	1460 reflections with I > 2σ(I)
T_min = 0.541, T_max = 0.618	R_int = 0.043
7266 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.052	84 restraints
wR(F²) = 0.179	H-atom parameters constrained
S = 0.94	Δρ_max = 0.46 e Å⁻³
2685 reflections	Δρ_min = −0.40 e Å⁻³
150 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
Br1	0.35688 (8)	0.65673 (6)	0.10127 (7)	0.0922 (4)
C1	0.7029 (6)	0.8851 (4)	0.1392 (4)	0.0489 (12)
C2	0.5759 (6)	0.8270 (4)	0.1476 (4)	0.0533 (14)
H2	0.5247	0.8477	0.1958	0.064*
C3	0.5254 (6)	0.7392 (5)	0.0851 (4)	0.0539 (14)
C4	0.5971 (7)	0.7079 (4)	0.0117 (4)	0.0557 (15)
H4	0.5608	0.6482	−0.0301	0.067*
C5	0.7232 (7)	0.7651 (4)	−0.0001 (5)	0.0585 (14)
C6	0.7756 (6)	0.8543 (4)	0.0646 (4)	0.0452 (13)
C7	0.7611 (8)	0.9814 (5)	0.2083 (5)	0.0662 (14)
H7	0.8701	0.9872	0.2130	0.079*
C8	0.6907 (11)	1.0865 (6)	0.1624 (7)	0.126 (3)
H8A	0.7162	1.0991	0.0990	0.188*
H8B	0.7283	1.1459	0.2084	0.188*
H8C	0.5822	1.0819	0.1505	0.188*
C9	0.7469 (11)	0.9636 (8)	0.3149 (6)	0.120 (3)
H9A	0.8150	1.0122	0.3607	0.180*
H9B	0.7725	0.8891	0.3348	0.180*
H9C	0.6443	0.9783	0.3175	0.180*
C10	0.8059 (9)	0.7265 (6)	−0.0773 (6)	0.0804 (16)
H10	0.8666	0.7876	−0.0923	0.096*
C11	0.9126 (12)	0.6347 (7)	−0.0315 (8)	0.132 (3)
H11A	0.9847	0.6606	0.0287	0.199*
H11B	0.9656	0.6101	−0.0802	0.199*
H11C	0.8555	0.5750	−0.0139	0.199*
C12	0.6986 (12)	0.6892 (8)	−0.1768 (7)	0.126 (3)
H12A	0.6336	0.6323	−0.1632	0.189*
H12B	0.7566	0.6616	−0.2214	0.189*
H12C	0.6378	0.7500	−0.2086	0.189*
C13	0.9228 (6)	0.9765 (4)	−0.0034 (4)	0.0512 (14)
C14	0.7932 (7)	1.0159 (6)	−0.0879 (5)	0.081 (2)
H14A	0.8104	0.9956	−0.1523	0.122*
H14B	0.7856	1.0942	−0.0843	0.122*
H14C	0.7003	0.9831	−0.0812	0.122*
N1	0.9141 (5)	0.9060 (3)	0.0633 (3)	0.0504 (11)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.0812 (6)	0.0846 (6)	0.1286 (8)	−0.0381 (4)	0.0595 (5)	−0.0188 (4)
C1	0.053 (3)	0.045 (3)	0.054 (3)	−0.005 (2)	0.023 (2)	−0.001 (2)
C2	0.053 (3)	0.054 (3)	0.058 (4)	−0.001 (3)	0.023 (3)	−0.001 (3)
C3	0.055 (3)	0.052 (3)	0.060 (4)	−0.011 (3)	0.026 (3)	0.005 (3)
C4	0.070 (4)	0.034 (3)	0.066 (4)	−0.014 (3)	0.024 (3)	−0.004 (3)
C5	0.075 (3)	0.043 (3)	0.070 (3)	−0.012 (3)	0.043 (3)	0.001 (3)
C6	0.046 (3)	0.037 (3)	0.055 (3)	−0.005 (2)	0.017 (3)	0.008 (2)
C7	0.076 (3)	0.062 (3)	0.067 (3)	−0.015 (3)	0.028 (3)	−0.015 (3)
C8	0.145 (7)	0.070 (5)	0.145 (6)	−0.001 (5)	0.005 (6)	−0.036 (5)
C9	0.155 (7)	0.131 (6)	0.083 (5)	−0.052 (5)	0.045 (5)	−0.038 (5)
C10	0.100 (4)	0.066 (3)	0.095 (4)	−0.016 (3)	0.060 (3)	−0.018 (3)
C11	0.131 (7)	0.129 (6)	0.163 (7)	0.022 (5)	0.085 (6)	−0.026 (6)
C12	0.153 (7)	0.147 (6)	0.100 (6)	−0.030 (6)	0.073 (5)	−0.040 (5)
C13	0.053 (3)	0.045 (3)	0.059 (4)	−0.006 (2)	0.019 (3)	0.007 (3)
C14	0.059 (4)	0.083 (5)	0.093 (5)	−0.012 (3)	0.005 (4)	0.039 (4)
N1	0.052 (3)	0.044 (3)	0.059 (3)	−0.006 (2)	0.022 (2)	0.005 (2)

Geometric parameters (Å, º) top

Br1—C3	1.894 (5)	C9—H9A	0.9600
C1—C2	1.384 (7)	C9—H9B	0.9600
C1—C6	1.396 (7)	C9—H9C	0.9600
C1—C7	1.511 (8)	C10—C11	1.507 (11)
C2—C3	1.371 (7)	C10—C12	1.517 (11)
C2—H2	0.9300	C10—H10	0.9800
C3—C4	1.376 (8)	C11—H11A	0.9600
C4—C5	1.387 (7)	C11—H11B	0.9600
C4—H4	0.9300	C11—H11C	0.9600
C5—C6	1.402 (7)	C12—H12A	0.9600
C5—C10	1.513 (8)	C12—H12B	0.9600
C6—N1	1.414 (7)	C12—H12C	0.9600
C7—C8	1.495 (10)	C13—N1	1.265 (6)
C7—C9	1.501 (9)	C13—C14	1.497 (8)
C7—H7	0.9800	C13—C13ⁱ	1.498 (10)
C8—H8A	0.9600	C14—H14A	0.9600
C8—H8B	0.9600	C14—H14B	0.9600
C8—H8C	0.9600	C14—H14C	0.9600

C2—C1—C6	118.8 (5)	H9A—C9—H9B	109.5
C2—C1—C7	120.9 (5)	C7—C9—H9C	109.5
C6—C1—C7	120.2 (5)	H9A—C9—H9C	109.5
C3—C2—C1	120.2 (5)	H9B—C9—H9C	109.5
C3—C2—H2	119.9	C11—C10—C5	109.2 (6)
C1—C2—H2	119.9	C11—C10—C12	110.1 (7)
C2—C3—C4	121.2 (5)	C5—C10—C12	112.8 (6)
C2—C3—Br1	119.7 (4)	C11—C10—H10	108.2
C4—C3—Br1	119.0 (4)	C5—C10—H10	108.2
C3—C4—C5	120.3 (5)	C12—C10—H10	108.2
C3—C4—H4	119.8	C10—C11—H11A	109.5
C5—C4—H4	119.8	C10—C11—H11B	109.5
C4—C5—C6	118.4 (5)	H11A—C11—H11B	109.5
C4—C5—C10	119.8 (5)	C10—C11—H11C	109.5
C6—C5—C10	121.7 (5)	H11A—C11—H11C	109.5
C1—C6—C5	121.1 (5)	H11B—C11—H11C	109.5
C1—C6—N1	118.6 (5)	C10—C12—H12A	109.5
C5—C6—N1	119.9 (5)	C10—C12—H12B	109.5
C8—C7—C9	113.0 (7)	H12A—C12—H12B	109.5
C8—C7—C1	111.3 (5)	C10—C12—H12C	109.5
C9—C7—C1	112.5 (5)	H12A—C12—H12C	109.5
C8—C7—H7	106.5	H12B—C12—H12C	109.5
C9—C7—H7	106.5	N1—C13—C14	125.7 (5)
C1—C7—H7	106.5	N1—C13—C13ⁱ	116.6 (6)
C7—C8—H8A	109.5	C14—C13—C13ⁱ	117.8 (6)
C7—C8—H8B	109.5	C13—C14—H14A	109.5
H8A—C8—H8B	109.5	C13—C14—H14B	109.5
C7—C8—H8C	109.5	H14A—C14—H14B	109.5
H8A—C8—H8C	109.5	C13—C14—H14C	109.5
H8B—C8—H8C	109.5	H14A—C14—H14C	109.5
C7—C9—H9A	109.5	H14B—C14—H14C	109.5
C7—C9—H9B	109.5	C13—N1—C6	122.2 (4)

C6—C1—C2—C3	1.6 (8)	C4—C5—C6—N1	172.3 (5)
C7—C1—C2—C3	−179.3 (5)	C10—C5—C6—N1	−4.1 (9)
C1—C2—C3—C4	−1.3 (9)	C2—C1—C7—C8	−90.6 (8)
C1—C2—C3—Br1	177.3 (4)	C6—C1—C7—C8	88.5 (8)
C2—C3—C4—C5	0.2 (9)	C2—C1—C7—C9	37.4 (8)
Br1—C3—C4—C5	−178.4 (4)	C6—C1—C7—C9	−143.5 (6)
C3—C4—C5—C6	0.4 (9)	C4—C5—C10—C11	−81.6 (8)
C3—C4—C5—C10	176.9 (6)	C6—C5—C10—C11	94.7 (8)
C2—C1—C6—C5	−0.9 (8)	C4—C5—C10—C12	41.1 (9)
C7—C1—C6—C5	180.0 (5)	C6—C5—C10—C12	−142.6 (7)
C2—C1—C6—N1	−173.4 (5)	C14—C13—N1—C6	0.5 (9)
C7—C1—C6—N1	7.5 (8)	C13ⁱ—C13—N1—C6	−179.2 (6)
C4—C5—C6—C1	−0.1 (8)	C1—C6—N1—C13	−106.2 (6)
C10—C5—C6—C1	−176.4 (6)	C5—C6—N1—C13	81.2 (7)

Symmetry code: (i) −x+2, −y+2, −z.

Experimental details

Crystal data
Chemical formula	C₂₈H₃₈Br₂N₂
M_r	562.42
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	296
a, b, c (Å)	9.099 (3), 12.199 (4), 13.566 (5)
β (°)	104.905 (5)
V (Å³)	1455.2 (9)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	2.80
Crystal size (mm)	0.25 × 0.23 × 0.19

Data collection
Diffractometer	Bruker APEXII CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2001)
T_min, T_max	0.541, 0.618
No. of measured, independent and observed [I > 2σ(I)] reflections	7266, 2685, 1460
R_int	0.043
(sin θ/λ)_max (Å⁻¹)	0.606

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.052, 0.179, 0.94
No. of reflections	2685
No. of parameters	150
No. of restraints	84
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.46, −0.40

Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXTL (Sheldrick, 2008).

Acknowledgements

This work was supported by the National Natural Science Foundation of China (Nos. 20927004, 21175108 and 20875077), the Natural Science Foundation of Gansu Province (Nos. 0803RJZA105, 096RJZA121 and 096RJZA122) and the Key Laboratory of Polymer Materials of Gansu Province, China.

References

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