organic compounds
4,6-Dibromo-N-{3-[(4,6-dibromo-2,3-dimethylphenyl)imino]butan-2-ylidene}-2,3-dimethylaniline
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: clinton_du@126.com
The title compound, C20H20Br4N2, is a product of the condensation reaction of 4,6-dibromo-2,3-dimethylaniline and butane-2,3-dione. The molecule has a center of symmetry at the mid-point of the central C—C bond. The dihedral angle between the benzene ring and the 1,4-diazabutadiene plane is 78.3 (2)°. Niether hydrogen bonding nor aromatic stacking is observed in the crystal structure.
Related literature
For applications of diimine–metal catalysts, see: Johnson et al. (1995). For related structures, see: Gao et al. (2012); Sun et al. (2012); Popeney et al. (2012); Shi et al. (2012); Zhang & Ye (2012); Killian et al. (1996); Yuan et al. (2005, 2011).
Experimental
Crystal data
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Data collection: CrysAlis PRO (Agilent, 2013); cell CrysAlis PRO; data reduction: CrysAlis RED (Agilent, 2013); program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007); program(s) used to refine structure: OLEX2 (Dolomanov et al., 2009); molecular graphics: OLEX2; software used to prepare material for publication: OLEX2.
Supporting information
10.1107/S1600536813023921/rk2409sup1.cif
contains datablock I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536813023921/rk2409Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536813023921/rk2409Isup3.cml
Formic acid (0.5 ml) was added to a stirred solution of 2,3–butanedione (0.09 g, 1.00 mmol) and 4,6–dibromo–2,3–dimethylaniline (0.61 g, 2.2 mmol) in ethanol (10 ml) (Fig. 2). The mixture was refluxed for 24 h, and then cooled and the precipitate was separated by filtration. The solid was recrystallized from EtOH/CH2Cl2 (v:v = 10:1), washed with cold ethanol and dried under vacuum to give the title compound1. Yield is 0.50 g (82%). Crystals suitable for X–ray
were grown from a cyclohexane/dichloromethane (v:v = 1:2) solution. Anal. Calcd. for C20H20Br4N2: C, 39.51; H, 3.32; Br, 52.57; N, 4.61. Found: C, 39.49; H, 3.31; Br, 52.60 N, 4.60.All hydrogen atoms were placed in calculated positions with C—H distances of 0.93Å and 0.96Å for aryl and methyl H atoms. They were included in the
in a riding model approximation, respectively. The H atoms were assigned Uiso = 1.2Ueq(C) for aryl H and Uiso = 1.5Ueq(C) for methyl H.Data collection: CrysAlis PRO (Agilent, 2013); cell
CrysAlis PRO (Agilent, 2013); data reduction: CrysAlis RED (Agilent, 2013); program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007); program(s) used to refine structure: OLEX2 (Dolomanov et al., 2009); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).C20H20Br4N2 | F(000) = 588 |
Mr = 607.98 | Dx = 1.922 Mg m−3 |
Monoclinic, P21/n | Cu Kα radiation, λ = 1.5418 Å |
a = 5.5582 (6) Å | Cell parameters from 2210 reflections |
b = 12.8881 (15) Å | θ = 3.4–70.4° |
c = 14.8377 (11) Å | µ = 9.40 mm−1 |
β = 98.782 (8)° | T = 150 K |
V = 1050.43 (19) Å3 | Block, clear light yellow |
Z = 2 | 0.29 × 0.17 × 0.16 mm |
Agilent SuperNova (Dual, Cu at zero, Eos) diffractometer | 1921 independent reflections |
Radiation source: SuperNova (Cu) X-ray Source | 1777 reflections with I > 2σ(I) |
Mirror monochromator | Rint = 0.029 |
Detector resolution: 16.0733 pixels mm-1 | θmax = 68.2°, θmin = 4.6° |
ω–scans | h = −6→4 |
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2013) | k = −15→15 |
Tmin = 0.688, Tmax = 1.000 | l = −17→17 |
4675 measured reflections |
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)] = 0.044 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.135 | H-atom parameters constrained |
S = 1.11 | w = 1/[σ2(Fo2) + (0.0802P)2 + 2.2115P] where P = (Fo2 + 2Fc2)/3 |
1921 reflections | (Δ/σ)max < 0.001 |
121 parameters | Δρmax = 0.70 e Å−3 |
0 restraints | Δρmin = −1.04 e Å−3 |
C20H20Br4N2 | V = 1050.43 (19) Å3 |
Mr = 607.98 | Z = 2 |
Monoclinic, P21/n | Cu Kα radiation |
a = 5.5582 (6) Å | µ = 9.40 mm−1 |
b = 12.8881 (15) Å | T = 150 K |
c = 14.8377 (11) Å | 0.29 × 0.17 × 0.16 mm |
β = 98.782 (8)° |
Agilent SuperNova (Dual, Cu at zero, Eos) diffractometer | 1921 independent reflections |
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2013) | 1777 reflections with I > 2σ(I) |
Tmin = 0.688, Tmax = 1.000 | Rint = 0.029 |
4675 measured reflections |
R[F2 > 2σ(F2)] = 0.044 | 0 restraints |
wR(F2) = 0.135 | H-atom parameters constrained |
S = 1.11 | Δρmax = 0.70 e Å−3 |
1921 reflections | Δρmin = −1.04 e Å−3 |
121 parameters |
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 | ||
Br2 | 0.84461 (11) | 0.31214 (5) | 0.68427 (4) | 0.0431 (2) | |
N1 | 0.5517 (8) | 0.5134 (4) | 0.6182 (3) | 0.0327 (9) | |
C2 | 0.2754 (9) | 0.4881 (4) | 0.8311 (3) | 0.0269 (9) | |
C3 | 0.6169 (9) | 0.3862 (4) | 0.7425 (3) | 0.0277 (10) | |
C4 | 0.4939 (9) | 0.4723 (4) | 0.7012 (3) | 0.0275 (10) | |
C5 | 0.3261 (10) | 0.5238 (4) | 0.7464 (3) | 0.0296 (10) | |
C6 | 0.4633 (10) | 0.4739 (4) | 0.5417 (3) | 0.0341 (11) | |
C7 | 0.5762 (9) | 0.3504 (4) | 0.8271 (3) | 0.0293 (10) | |
H7 | 0.6616 | 0.2939 | 0.8548 | 0.035* | |
C1 | 0.1862 (10) | 0.6189 (4) | 0.7022 (3) | 0.0341 (11) | |
H1A | 0.0200 | 0.5999 | 0.6813 | 0.051* | |
H1B | 0.2604 | 0.6422 | 0.6515 | 0.051* | |
H1C | 0.1912 | 0.6736 | 0.7463 | 0.051* | |
C8 | 0.2980 (12) | 0.3814 (5) | 0.5268 (3) | 0.0438 (14) | |
H8A | 0.1479 | 0.4010 | 0.4898 | 0.066* | |
H8B | 0.2654 | 0.3560 | 0.5845 | 0.066* | |
H8C | 0.3751 | 0.3278 | 0.4964 | 0.066* | |
C9 | 0.0867 (10) | 0.5414 (4) | 0.8773 (4) | 0.0378 (12) | |
H9A | 0.1616 | 0.5968 | 0.9148 | 0.057* | |
H9B | 0.0170 | 0.4924 | 0.9146 | 0.057* | |
H9C | −0.0388 | 0.5691 | 0.8321 | 0.057* | |
C10 | 0.4039 (9) | 0.4017 (4) | 0.8689 (3) | 0.0277 (10) | |
Br1 | 0.34078 (11) | 0.34478 (4) | 0.98167 (3) | 0.0379 (2) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br2 | 0.0473 (4) | 0.0546 (4) | 0.0317 (3) | −0.0012 (3) | 0.0199 (3) | −0.0110 (2) |
N1 | 0.043 (2) | 0.043 (2) | 0.0129 (18) | −0.0155 (19) | 0.0064 (16) | 0.0029 (17) |
C2 | 0.035 (2) | 0.030 (2) | 0.017 (2) | −0.0044 (19) | 0.0075 (17) | −0.0020 (17) |
C3 | 0.038 (2) | 0.032 (2) | 0.015 (2) | −0.005 (2) | 0.0109 (17) | −0.0075 (18) |
C4 | 0.042 (3) | 0.032 (2) | 0.0096 (19) | −0.012 (2) | 0.0066 (17) | −0.0023 (17) |
C5 | 0.047 (3) | 0.026 (2) | 0.015 (2) | −0.006 (2) | 0.0046 (19) | 0.0011 (18) |
C6 | 0.047 (3) | 0.044 (3) | 0.013 (2) | −0.016 (2) | 0.0102 (19) | 0.001 (2) |
C7 | 0.042 (3) | 0.025 (2) | 0.022 (2) | −0.003 (2) | 0.007 (2) | −0.0012 (17) |
C1 | 0.053 (3) | 0.029 (2) | 0.019 (2) | −0.004 (2) | 0.001 (2) | 0.0107 (19) |
C8 | 0.061 (4) | 0.058 (3) | 0.013 (2) | −0.031 (3) | 0.007 (2) | 0.000 (2) |
C9 | 0.045 (3) | 0.042 (3) | 0.029 (3) | 0.005 (2) | 0.015 (2) | −0.003 (2) |
C10 | 0.044 (3) | 0.030 (2) | 0.0102 (18) | −0.004 (2) | 0.0077 (17) | 0.0000 (17) |
Br1 | 0.0605 (4) | 0.0407 (4) | 0.0159 (3) | 0.0013 (2) | 0.0171 (2) | 0.00654 (19) |
Br2—C3 | 1.895 (5) | C7—H7 | 0.9300 |
N1—C4 | 1.422 (6) | C7—C10 | 1.385 (7) |
N1—C6 | 1.273 (6) | C1—H1A | 0.9600 |
C2—C5 | 1.406 (6) | C1—H1B | 0.9600 |
C2—C9 | 1.504 (7) | C1—H1C | 0.9600 |
C2—C10 | 1.395 (7) | C8—H8A | 0.9600 |
C3—C4 | 1.395 (7) | C8—H8B | 0.9600 |
C3—C7 | 1.388 (6) | C8—H8C | 0.9600 |
C4—C5 | 1.397 (7) | C9—H9A | 0.9600 |
C5—C1 | 1.543 (7) | C9—H9B | 0.9600 |
C6—C6i | 1.518 (9) | C9—H9C | 0.9600 |
C6—C8 | 1.501 (7) | C10—Br1 | 1.908 (4) |
C6—N1—C4 | 121.1 (4) | C5—C1—H1B | 109.5 |
C5—C2—C9 | 120.5 (5) | C5—C1—H1C | 109.5 |
C10—C2—C5 | 117.4 (4) | H1A—C1—H1B | 109.5 |
C10—C2—C9 | 122.1 (4) | H1A—C1—H1C | 109.5 |
C4—C3—Br2 | 121.1 (3) | H1B—C1—H1C | 109.5 |
C7—C3—Br2 | 117.2 (4) | C6—C8—H8A | 109.5 |
C7—C3—C4 | 121.6 (4) | C6—C8—H8B | 109.5 |
C3—C4—N1 | 121.1 (4) | C6—C8—H8C | 109.5 |
C3—C4—C5 | 119.1 (4) | H8A—C8—H8B | 109.5 |
C5—C4—N1 | 119.6 (4) | H8A—C8—H8C | 109.5 |
C2—C5—C1 | 118.9 (5) | H8B—C8—H8C | 109.5 |
C4—C5—C2 | 120.9 (4) | C2—C9—H9A | 109.5 |
C4—C5—C1 | 120.2 (4) | C2—C9—H9B | 109.5 |
N1—C6—C6i | 115.8 (6) | C2—C9—H9C | 109.5 |
N1—C6—C8 | 126.4 (4) | H9A—C9—H9B | 109.5 |
C8—C6—C6i | 117.8 (5) | H9A—C9—H9C | 109.5 |
C3—C7—H7 | 121.1 | H9B—C9—H9C | 109.5 |
C10—C7—C3 | 117.8 (5) | C2—C10—Br1 | 120.6 (4) |
C10—C7—H7 | 121.1 | C7—C10—C2 | 123.2 (4) |
C5—C1—H1A | 109.5 | C7—C10—Br1 | 116.2 (4) |
Br2—C3—C4—N1 | −6.1 (6) | C5—C2—C10—C7 | −0.1 (7) |
Br2—C3—C4—C5 | 179.4 (3) | C5—C2—C10—Br1 | −178.0 (4) |
Br2—C3—C7—C10 | −177.8 (4) | C6—N1—C4—C3 | 82.4 (7) |
N1—C4—C5—C2 | −176.5 (4) | C6—N1—C4—C5 | −103.1 (6) |
N1—C4—C5—C1 | 5.7 (7) | C7—C3—C4—N1 | 174.7 (4) |
C3—C4—C5—C2 | −1.9 (7) | C7—C3—C4—C5 | 0.2 (7) |
C3—C4—C5—C1 | −179.7 (4) | C9—C2—C5—C4 | −177.4 (5) |
C3—C7—C10—C2 | −1.5 (7) | C9—C2—C5—C1 | 0.4 (7) |
C3—C7—C10—Br1 | 176.5 (4) | C9—C2—C10—C7 | 179.1 (5) |
C4—N1—C6—C6i | 179.2 (6) | C9—C2—C10—Br1 | 1.2 (7) |
C4—N1—C6—C8 | −1.5 (10) | C10—C2—C5—C4 | 1.8 (7) |
C4—C3—C7—C10 | 1.5 (7) | C10—C2—C5—C1 | 179.6 (4) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C20H20Br4N2 |
Mr | 607.98 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 150 |
a, b, c (Å) | 5.5582 (6), 12.8881 (15), 14.8377 (11) |
β (°) | 98.782 (8) |
V (Å3) | 1050.43 (19) |
Z | 2 |
Radiation type | Cu Kα |
µ (mm−1) | 9.40 |
Crystal size (mm) | 0.29 × 0.17 × 0.16 |
Data collection | |
Diffractometer | Agilent SuperNova (Dual, Cu at zero, Eos) diffractometer |
Absorption correction | Multi-scan (CrysAlis PRO; Agilent, 2013) |
Tmin, Tmax | 0.688, 1.000 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4675, 1921, 1777 |
Rint | 0.029 |
(sin θ/λ)max (Å−1) | 0.602 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.044, 0.135, 1.11 |
No. of reflections | 1921 |
No. of parameters | 121 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.70, −1.04 |
Computer programs: CrysAlis PRO (Agilent, 2013), CrysAlis RED (Agilent, 2013), SUPERFLIP (Palatinus & Chapuis, 2007), OLEX2 (Dolomanov et al., 2009).
Acknowledgements
We gratefully acknowledge the Natural Science Foundation of China (20702042, 21262028), the Program for Changjiang Scholars and Innovative Research Teams in Universities of the Ministry of Education of China (IRT1177), the Natural Science Foundation of Gansu Province (1208RJZA140) and the NWNU Young Teachers Reseach Improving Program (NWNU–LKQN–10–11) for financial support.
References
Agilent (2013). CrysAlis PRO and CrysAlis RED. Agilent Technologies. Yarnton, England. Google Scholar
Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341. Web of Science CrossRef CAS IUCr Journals Google Scholar
Gao, H., Hu, H., Zhu, F. & Wu, Q. (2012). Chem. Commun. 48, 3312–3314. Web of Science CSD CrossRef CAS Google Scholar
Johnson, L. K., Killian, C. M. & Brookhart, M. (1995). J. Am. Chem. Soc. 117, 6414–6415. CrossRef CAS Web of Science Google Scholar
Killian, C. M., Tempel, D., Johnson, L. K. & Brookhart, M. (1996). J. Am. Chem. Soc. 118, 11664–11665. CrossRef CAS Web of Science Google Scholar
Palatinus, L. & Chapuis, G. (2007). J. Appl. Cryst. 40, 786–790. Web of Science CrossRef CAS IUCr Journals Google Scholar
Popeney, C. S., Lukowiak, M. C., Böttcher, C., Schade, B., Welker, P., Mangoldt, D., Gunkel, G., Guan, Z. B. & Haag, R. (2012). ACS Macro. Lett. 1, 564–567. Web of Science CrossRef CAS Google Scholar
Shi, X., Zhao, Y., Gao, H., Zhang, L., Zhu, F. & Wu, Q. (2012). Macromol. Rapid Commun. 33, 374–379. Web of Science CrossRef CAS PubMed Google Scholar
Sun, G. B., Hentschel, J. & Guan, Z. B. (2012). ACS Macro. Lett. 1, 585–588. Web of Science CrossRef CAS Google Scholar
Yuan, J. C., Mei, T. J., Gomes, P. T., Marques, M. M., Wang, X. H., Liu, Y. F., Miao, C. P. & Xie, X. L. (2011). J. Organomet. Chem. 696, 3251–3256. Web of Science CSD CrossRef CAS Google Scholar
Yuan, J. C., Silva, L. C., Gomes, P. T., Campos, J. M., Riberio, M. R., Valerga, P. S., Chien, J. C. W. & Marques, M. M. (2005). Polymer, 46, 2122–2132. Web of Science CSD CrossRef CAS Google Scholar
Zhang, Z. & Ye, Z. (2012). Chem. Commun. 48, 7940–7942. Web of Science CrossRef CAS Google Scholar
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Since Brookhart and co–workers discovered nickel and palladium(II) aryl–substituted α–diimine catalysts for olefin polymerization (Johnson et al., 1995), late transition metal catalysis has attracted increasing attention due to their high functional group tolerance and their ability to produce branched or dendritic polymer (Gao et al., 2012; Sun et al., 2012; Popeney et al., 2012; Shi et al., 2012; Zhang & Ye, 2012; Killian et al., 1996; Yuan et al., 2005;2011). In this study, we designed and synthesized the title compound as abidentate ligand (Fig. 1).
The title molecule placed in center of symmetry (middle of C6—C6i bond). The dihedral angle between the benzene ring and 1,4–diazabutadiene plane is 78.3 (2)°. Niether hydrogen bonding nor aromatic stacking are observed in the crystal structure.