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accessN,N′-Bis[1-(pyridin-2-yl)ethylidene]benzene-1,4-diamine
aDepartment of Chemistry, Harbin Institute of Technology, Harbin 150001, People's Republic of China
*Correspondence e-mail: fanruiqing@hit.edu.cn
In the title compound, C20H18N4, the benzene ring lies about an inversion center. The central benzene-1,4-diamine unit is connected to two pyridine rings by the C=N imine bonds. The dihedral angle between the benzene and pyridine rings is 82.9 (1)°.
Related literature
For background information on derived from pyridinecarbaldehydes, see: Marjani et al. (2009![[Marjani, K., Asgarian, J., Mousavi, M. & Amani, V. (2009). Z. Anorg. Allg. Chem. 635, 1633-1637.]](../../../../../../logos/arrows/e_arr.gif "Marjani, K., Asgarian, J., Mousavi, M. & Amani, V. (2009). Z. Anorg. Allg. Chem. 635, 1633-1637.")
). For pyridine-derived as bidentate chelating ligands towards metal centers, see: Wu et al. (2006). For a related structure, see: Marjani et al. (2011). For the synthesis of the title compound, see: Yoshida et al. (2000).
![[Scheme 1]](pv2550scheme1.gif)
Experimental
Crystal data
|
Data collection: SMART (Bruker, 2000); cell SAINT (Bruker, 2000); 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
contains datablocks global, I. DOI: https://doi.org/10.1107/S1600536812025834/pv2550sup1.cif
Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536812025834/pv2550Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S1600536812025834/pv2550Isup3.cml
The title compound was synthesized by usual Schiff-base condensation of benzene-1,4-diamine and 2-acetyl pyridine. 2-Acetylpyridine (4.50 ml, 0.04 mol) was added in an ethanol (100 mL) solution of benzene-1,4-diamine (2.16 g, 0.02 mol) at room temperature. After the addition was completed, the reaction mixture was heated to 343–353 K and refluxed for 6 h (Yoshida et al., 2000). Then the resultant precipitate was filtered off, washed with ethanol, dried in air and 5.06 g (Yield: 80.6%) brown product was obtained. The crystals of the title compound suitable for X-ray analysis ewere obtained by recrystallization from a mixture of hexane and dichloromethane (3:1).
The C-bound H atoms were positioned geometrically with C—H = 0.93 and 0.96 Å, for aryl and methyl H-atoms, respectively, and allowed to ride on their parent atoms with Uiso(H) = 1.5 Ueq(C-methyl) or 1.2 Ueq(C-aryl).
Schiff bases derived from pyridinecarbaldehydes have received considerable interest in synthetic chemistry (Marjani et al., 2009). N,N'-bis(1-pyridin-2-ylmethylene)benzene-1,4-diamine is a pyridine derived Schiff base, which acts as bidentate chelating ligand towards metal centers (Wu et al., 2006). It is still challenging to design and rationally synthesize ligands with unique structures and functions. In this regard, we have synthesized the title compound and report its in this paper.
The title compound (Fig. 1) lies on an inversion center. The dihedral angle between 1,4-diamine-substituted benzene ring and the pyridine ring is 82.9 (1)°. The bond lengths and bond angles in the title molecule agree very well with the corresponding bond distances and bond angles reported in a closely related compound (Marjani et al., 2011).
For background information on derived from pyridinecarbaldehydes, see: Marjani et al. (2009). For pyridine-derived as bidentate chelating ligands towards metal centers, see: Wu et al. (2006). For a related structure, see: Marjani et al. (2011). For the synthesis of the title compound, see: Yoshida et al. (2000).
Data collection: SMART (Bruker, 2000); cell SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); 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).
![[Figure 1]](./pv2550fig1thm.gif) | Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are presented as small spheres of arbitrary radius. |
![[Figure 2]](./pv2550fig2thm.gif) | Fig. 2. A view of the unit cell packing of the title compound along the a-axis. |
| C20H18N4 | F(000) = 332 |
| Mr = 314.38 | Dx = 1.228 Mg m−3 |
| Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -P 2ybc | Cell parameters from 7961 reflections |
| a = 5.4660 (11) Å | θ = 3.1–27.5° |
| b = 6.8510 (14) Å | µ = 0.08 mm−1 |
| c = 22.704 (5) Å | T = 293 K |
| β = 90.45 (3)° | Block, brown |
| V = 850.2 (3) Å3 | 0.50 × 0.48 × 0.19 mm |
| Z = 2 |
| Bruker SMART APEX CCD area-detector diffractometer | 1949 independent reflections |
| Radiation source: fine-focus sealed tube | 1180 reflections with I > 2σ(I) |
| Graphite monochromator | Rint = 0.037 |
| φ & ω scans | θmax = 27.5°, θmin = 3.1° |
| Absorption correction: multi-scan (SADABS; Bruker, 2000) | h = −7→7 |
| Tmin = 0.964, Tmax = 0.986 | k = −8→8 |
| 7961 measured reflections | l = −29→29 |
| 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) = 0.155 | H-atom parameters constrained |
| S = 1.05 | w = 1/[σ2(Fo2) + (0.0759P)2 + 0.0618P] where P = (Fo2 + 2Fc2)/3 |
| 1949 reflections | (Δ/σ)max = 0.005 |
| 109 parameters | Δρmax = 0.18 e Å−3 |
| 0 restraints | Δρmin = −0.15 e Å−3 |
| C20H18N4 | V = 850.2 (3) Å3 |
| Mr = 314.38 | Z = 2 |
| Monoclinic, P21/c | Mo Kα radiation |
| a = 5.4660 (11) Å | µ = 0.08 mm−1 |
| b = 6.8510 (14) Å | T = 293 K |
| c = 22.704 (5) Å | 0.50 × 0.48 × 0.19 mm |
| β = 90.45 (3)° |
| Bruker SMART APEX CCD area-detector diffractometer | 1949 independent reflections |
| Absorption correction: multi-scan (SADABS; Bruker, 2000) | 1180 reflections with I > 2σ(I) |
| Tmin = 0.964, Tmax = 0.986 | Rint = 0.037 |
| 7961 measured reflections |
| R[F2 > 2σ(F2)] = 0.052 | 0 restraints |
| wR(F2) = 0.155 | H-atom parameters constrained |
| S = 1.05 | Δρmax = 0.18 e Å−3 |
| 1949 reflections | Δρmin = −0.15 e Å−3 |
| 109 parameters |
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. |
| x | y | z | Uiso*/Ueq | ||
| N1 | 0.1873 (3) | −0.0704 (3) | 0.18884 (6) | 0.0716 (5) | |
| N2 | 0.2608 (3) | 0.1865 (2) | 0.05548 (6) | 0.0596 (4) | |
| C1 | 0.1296 (3) | −0.0097 (2) | 0.13471 (7) | 0.0494 (4) | |
| C2 | −0.0609 (4) | −0.0910 (3) | 0.10286 (8) | 0.0648 (5) | |
| H2B | −0.0943 | −0.0491 | 0.0647 | 0.078* | |
| C3 | −0.2011 (4) | −0.2348 (3) | 0.12820 (9) | 0.0726 (6) | |
| H3A | −0.3327 | −0.2888 | 0.1077 | 0.087* | |
| C4 | −0.1442 (4) | −0.2972 (3) | 0.18377 (8) | 0.0688 (6) | |
| H4A | −0.2354 | −0.3943 | 0.2020 | 0.083* | |
| C5 | 0.0496 (5) | −0.2129 (3) | 0.21166 (8) | 0.0812 (7) | |
| H5A | 0.0895 | −0.2573 | 0.2492 | 0.097* | |
| C6 | 0.2806 (3) | 0.1525 (2) | 0.11021 (7) | 0.0520 (4) | |
| C7 | 0.4428 (5) | 0.2623 (4) | 0.15204 (8) | 0.0847 (8) | |
| H7A | 0.5292 | 0.3620 | 0.1310 | 0.127* | |
| H7B | 0.5581 | 0.1740 | 0.1698 | 0.127* | |
| H7C | 0.3451 | 0.3213 | 0.1822 | 0.127* | |
| C8 | 0.3870 (4) | 0.3453 (2) | 0.02905 (7) | 0.0543 (5) | |
| C9 | 0.5992 (4) | 0.3148 (3) | −0.00200 (8) | 0.0620 (5) | |
| H9A | 0.6668 | 0.1904 | −0.0038 | 0.074* | |
| C10 | 0.2881 (4) | 0.5319 (3) | 0.03045 (8) | 0.0620 (5) | |
| H10A | 0.1438 | 0.5539 | 0.0508 | 0.074* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| N1 | 0.0910 (13) | 0.0761 (11) | 0.0477 (8) | −0.0290 (10) | −0.0058 (8) | 0.0046 (8) |
| N2 | 0.0716 (11) | 0.0492 (8) | 0.0578 (9) | −0.0189 (7) | −0.0079 (7) | 0.0080 (7) |
| C1 | 0.0578 (10) | 0.0432 (9) | 0.0473 (9) | −0.0031 (7) | 0.0024 (7) | −0.0036 (7) |
| C2 | 0.0734 (13) | 0.0631 (11) | 0.0576 (10) | −0.0170 (10) | −0.0117 (9) | 0.0134 (9) |
| C3 | 0.0763 (14) | 0.0710 (13) | 0.0702 (12) | −0.0295 (11) | −0.0100 (10) | 0.0076 (10) |
| C4 | 0.0838 (15) | 0.0633 (12) | 0.0593 (11) | −0.0227 (10) | 0.0052 (10) | 0.0074 (9) |
| C5 | 0.1055 (19) | 0.0862 (15) | 0.0517 (10) | −0.0361 (14) | −0.0083 (11) | 0.0136 (10) |
| C6 | 0.0592 (11) | 0.0423 (9) | 0.0544 (9) | −0.0056 (8) | 0.0012 (8) | −0.0049 (7) |
| C7 | 0.1068 (19) | 0.0858 (15) | 0.0614 (12) | −0.0455 (14) | −0.0065 (11) | −0.0030 (11) |
| C8 | 0.0627 (12) | 0.0460 (9) | 0.0540 (9) | −0.0148 (8) | −0.0114 (8) | 0.0043 (7) |
| C9 | 0.0688 (13) | 0.0434 (9) | 0.0738 (12) | −0.0035 (9) | −0.0051 (10) | 0.0054 (8) |
| C10 | 0.0627 (12) | 0.0530 (11) | 0.0704 (11) | −0.0102 (9) | 0.0026 (9) | 0.0048 (9) |
| N1—C1 | 1.333 (2) | C5—H5A | 0.9300 |
| N1—C5 | 1.339 (3) | C6—C7 | 1.497 (3) |
| N2—C6 | 1.268 (2) | C7—H7A | 0.9600 |
| N2—C8 | 1.424 (2) | C7—H7B | 0.9600 |
| C1—C2 | 1.381 (3) | C7—H7C | 0.9600 |
| C1—C6 | 1.494 (2) | C8—C9 | 1.378 (3) |
| C2—C3 | 1.377 (3) | C8—C10 | 1.389 (3) |
| C2—H2B | 0.9300 | C9—C10i | 1.381 (3) |
| C3—C4 | 1.366 (3) | C9—H9A | 0.9300 |
| C3—H3A | 0.9300 | C10—C9i | 1.381 (3) |
| C4—C5 | 1.359 (3) | C10—H10A | 0.9300 |
| C4—H4A | 0.9300 | ||
| C1—N1—C5 | 117.03 (16) | N2—C6—C7 | 125.11 (16) |
| C6—N2—C8 | 121.03 (14) | C1—C6—C7 | 117.61 (14) |
| N1—C1—C2 | 121.94 (16) | C6—C7—H7A | 109.5 |
| N1—C1—C6 | 116.62 (15) | C6—C7—H7B | 109.5 |
| C2—C1—C6 | 121.44 (15) | H7A—C7—H7B | 109.5 |
| C3—C2—C1 | 119.34 (16) | C6—C7—H7C | 109.5 |
| C3—C2—H2B | 120.3 | H7A—C7—H7C | 109.5 |
| C1—C2—H2B | 120.3 | H7B—C7—H7C | 109.5 |
| C4—C3—C2 | 119.11 (18) | C9—C8—C10 | 118.74 (17) |
| C4—C3—H3A | 120.4 | C9—C8—N2 | 120.83 (17) |
| C2—C3—H3A | 120.4 | C10—C8—N2 | 120.26 (18) |
| C5—C4—C3 | 117.95 (18) | C8—C9—C10i | 120.31 (17) |
| C5—C4—H4A | 121.0 | C8—C9—H9A | 119.8 |
| C3—C4—H4A | 121.0 | C10i—C9—H9A | 119.8 |
| N1—C5—C4 | 124.60 (18) | C9i—C10—C8 | 120.95 (19) |
| N1—C5—H5A | 117.7 | C9i—C10—H10A | 119.5 |
| C4—C5—H5A | 117.7 | C8—C10—H10A | 119.5 |
| N2—C6—C1 | 117.28 (15) |
| Symmetry code: (i) −x+1, −y+1, −z. |
Experimental details
| Crystal data | |
| Chemical formula | C20H18N4 |
| Mr | 314.38 |
| Crystal system, space group | Monoclinic, P21/c |
| Temperature (K) | 293 |
| a, b, c (Å) | 5.4660 (11), 6.8510 (14), 22.704 (5) |
| β (°) | 90.45 (3) |
| V (Å3) | 850.2 (3) |
| Z | 2 |
| Radiation type | Mo Kα |
| µ (mm−1) | 0.08 |
| Crystal size (mm) | 0.50 × 0.48 × 0.19 |
| Data collection | |
| Diffractometer | Bruker SMART APEX CCD area-detector |
| Absorption correction | Multi-scan (SADABS; Bruker, 2000) |
| Tmin, Tmax | 0.964, 0.986 |
| No. of measured, independent and observed [I > 2σ(I)] reflections | 7961, 1949, 1180 |
| Rint | 0.037 |
| (sin θ/λ)max (Å−1) | 0.649 |
| Refinement | |
| R[F2 > 2σ(F2)], wR(F2), S | 0.052, 0.155, 1.05 |
| No. of reflections | 1949 |
| No. of parameters | 109 |
| H-atom treatment | H-atom parameters constrained |
| Δρmax, Δρmin (e Å−3) | 0.18, −0.15 |
Computer programs: SMART (Bruker, 2000), SAINT (Bruker, 2000), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
Acknowledgements
This work was supported by the National Natural Science Foundation of China (grant Nos. 20971031, 21071035 and 21171044), the China Postdoctoral Science Foundation Funded Project (No. 65204) and the Key Natural Science Foundation of Heilongjiang Province, China (No. ZD201009).
References
Bruker (2000). SMART, SAINT and SADABS Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Marjani, K., Asgarian, J., Mousavi, M. & Amani, V. (2009). Z. Anorg. Allg. Chem. 635, 1633–1637. Web of Science CSD CrossRef CAS Google Scholar
Marjani, K., Mousavi, M. & Namazian, F. (2011). J. Chem. Crystallogr. 41, 1451–1455. Web of Science CSD CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Wu, H. C., Thanasekaran, P., Tsai, C. H., Wu, J. Y., Huang, S. M., Wen, Y. S. & Lu, K. L. (2006). Inorg. Chem. 45, 295–303. Web of Science CSD CrossRef PubMed CAS Google Scholar
Yoshida, N., Ichikawa, K. & Shiro, M. (2000). J. Chem. Soc., Perkin Trans. 2, pp. 17–26. Google Scholar
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| CRYSTALLOGRAPHIC COMMUNICATIONS |
Schiff bases derived from pyridinecarbaldehydes have received considerable interest in synthetic chemistry (Marjani et al., 2009). N,N'-bis(1-pyridin-2-ylmethylene)benzene-1,4-diamine is a pyridine derived Schiff base, which acts as bidentate chelating ligand towards metal centers (Wu et al., 2006). It is still challenging to design and rationally synthesize ligands with unique structures and functions. In this regard, we have synthesized the title compound and report its crystal structure in this paper.
The title compound (Fig. 1) lies on an inversion center. The dihedral angle between 1,4-diamine-substituted benzene ring and the pyridine ring is 82.9 (1)°. The bond lengths and bond angles in the title molecule agree very well with the corresponding bond distances and bond angles reported in a closely related compound (Marjani et al., 2011).