organic compounds
1,4-Bis[(2-pyridylethyl)iminomethyl]benzene
aDepartment of Chemistry, University of Cape Town, Private Bag, Rondebosch 7707, South Africa, bDivision of Medical Biochemistry, Faculty of Health Sciences, Private Bag X3, Observatory 7935, South Africa, and cDepartment of Chemistry University of Johannesburg, PO Box 524, Auckland Park, Johannesburg 2006, South Africa.
*Correspondence e-mail: harrychiririwa@yahoo.com
In the title compound, C22H22N4, the centroid of the benzene ring is located on an inversion centre. The dihedral angle between the benzene and pyridine rings is 10.94 (5)°. The displays weak intermolecular C—H⋯N hydrogen bonding and C—H⋯π interactions.
Experimental
Crystal data
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Data collection
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Refinement
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Data collection: APEX2 (Bruker, 2006); cell SAINT (Bruker, 2006); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).
Supporting information
10.1107/S1600536811009809/go2006sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536811009809/go2006Isup2.hkl
The title compound was synthesized as follows: a solution of benzene 1,4-dicarboxaldehyde (0.50 g, 3.73 mmol) in methanol (10 ml) was added dropwise to a stirred solution of 2-(pyridin-2-yl)ethanamine(0.91 g, 7.42 mmol) in methanol (10 ml). The mixture was stirred at room temperature for ca 16 h. The precipitate was filtered off and washed with diethylether and dried under vacuum for 4 h affording a fine shiny white powder in 85% yield. M.p.: does not melt below 260 °C. Recrystallization by slow diffusion of Et2O into a concentrated CH2Cl2 of the solution gave colorless crystals suitable for X-ray structure analysis.
All non-hydrogen atoms were refined anisotropically and all hydrogen atoms were placed in idealized positions and refined with a riding model with Uiso set at 1.2 or 1.5 times Ueq of their parent atoms and fixed C—H bond lengths.
Data collection: APEX2 (Bruker, 2006); cell
SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).Fig. 1. Molecular structure of titled compound showing the atomic numbering scheme. All non-hydrogen atoms were presented with ellipsoidal model with probability level 40%. Half of the molecule without atomic labels was generated via centre of symmetry (symmetry code: -x, -y, -z). | |
Fig. 2. Projection viewed along [100] showing 3-D herringbone packing. Only the hydrogen atoms that invloved in C—H···N and C—H···π intermolecular interactions (see the list in Table 1) are shown and labelled. The red dotted lines represent the weak interactions. |
C22H22N4 | F(000) = 364 |
Mr = 342.44 | Dx = 1.234 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 11941 reflections |
a = 6.0078 (6) Å | θ = 3.1–28.3° |
b = 26.023 (3) Å | µ = 0.08 mm−1 |
c = 6.1319 (7) Å | T = 173 K |
β = 106.009 (2)° | Plate, colourless |
V = 921.47 (17) Å3 | 0.26 × 0.24 × 0.17 mm |
Z = 2 |
Bruker Kappa DUO APEXII diffractometer | 1945 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.024 |
Graphite monochromator | θmax = 28.3°, θmin = 3.1° |
0.5° ϕ scans and ω | h = −8→8 |
11941 measured reflections | k = −34→33 |
2288 independent reflections | l = −8→8 |
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)] = 0.040 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.110 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0506P)2 + 0.2363P] where P = (Fo2 + 2Fc2)/3 |
2288 reflections | (Δ/σ)max < 0.001 |
118 parameters | Δρmax = 0.28 e Å−3 |
0 restraints | Δρmin = −0.20 e Å−3 |
C22H22N4 | V = 921.47 (17) Å3 |
Mr = 342.44 | Z = 2 |
Monoclinic, P21/n | Mo Kα radiation |
a = 6.0078 (6) Å | µ = 0.08 mm−1 |
b = 26.023 (3) Å | T = 173 K |
c = 6.1319 (7) Å | 0.26 × 0.24 × 0.17 mm |
β = 106.009 (2)° |
Bruker Kappa DUO APEXII diffractometer | 1945 reflections with I > 2σ(I) |
11941 measured reflections | Rint = 0.024 |
2288 independent reflections |
R[F2 > 2σ(F2)] = 0.040 | 0 restraints |
wR(F2) = 0.110 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.28 e Å−3 |
2288 reflections | Δρmin = −0.20 e Å−3 |
118 parameters |
Experimental. Data for (I): IR (KBr): 1610 cm-1 (C=N, imine) 1HNMR:(CDCl3) δH 8.55(ddd, 2H, J =0.8 Hz, J = 1.7 Hz, J = 4.8 Hz) 8.21 (t, 2H, J = 1.3 Hz) 7.69 (s, 2H) 7.55 (dt, 2H, J = 1.9 Hz, J = 7.7 Hz) 7.11 (m, 2H) 4.03 (dt, 8H, J = 1.2 Hz, J = 7.2 Hz) 3.19(t, 4H, J = 7.2 Hz); 13CNMR: (400 MHz, CDCl3) δ 161.05, 159.45, 149.37, 138.88, 136.13, 128.21, 123.67, 121.24, 61.18, 39.61; Analysis calculated for C22H22N4:C, 77.16%; H, 6.48%; N, 16.36%; Found: C, 77.19%; H, 6.22%; N, 16.52%; EI—MS: m/z 249.90[M – C7H6N]+. Half sphere of data collected using SAINT strategy (Bruker, 2006). Crystal to detector distance = 50 mm; combination of ϕ and ω scans of 0.5°, 40 s per °, 2 iterations. |
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 | 1.01974 (18) | 0.16910 (4) | 0.82099 (17) | 0.0365 (3) | |
C1 | 1.1434 (2) | 0.20288 (5) | 0.9711 (2) | 0.0431 (3) | |
H1 | 1.2675 | 0.2201 | 0.9339 | 0.052* | |
N2 | 0.40565 (16) | 0.09448 (4) | 0.35620 (15) | 0.0282 (2) | |
C2 | 1.1022 (2) | 0.21422 (5) | 1.1750 (2) | 0.0406 (3) | |
H2 | 1.1936 | 0.2389 | 1.2748 | 0.049* | |
C3 | 0.9248 (2) | 0.18885 (5) | 1.2306 (2) | 0.0381 (3) | |
H3 | 0.8928 | 0.1952 | 1.3715 | 0.046* | |
C4 | 0.7937 (2) | 0.15394 (4) | 1.07884 (19) | 0.0312 (3) | |
H4 | 0.6689 | 0.1363 | 1.1130 | 0.037* | |
C5 | 0.84667 (18) | 0.14496 (4) | 0.87569 (18) | 0.0252 (2) | |
C6 | 0.7121 (2) | 0.10708 (4) | 0.7047 (2) | 0.0327 (3) | |
H6A | 0.6662 | 0.0778 | 0.7860 | 0.039* | |
H6B | 0.8134 | 0.0936 | 0.6152 | 0.039* | |
C7 | 0.49617 (19) | 0.13015 (4) | 0.54368 (19) | 0.0283 (2) | |
H7A | 0.3778 | 0.1365 | 0.6254 | 0.034* | |
H7B | 0.5346 | 0.1634 | 0.4844 | 0.034* | |
C8 | 0.21489 (18) | 0.07288 (4) | 0.34628 (17) | 0.0251 (2) | |
H8 | 0.1384 | 0.0810 | 0.4584 | 0.030* | |
C9 | 0.10603 (17) | 0.03556 (4) | 0.16772 (17) | 0.0231 (2) | |
C10 | −0.10072 (18) | 0.01157 (4) | 0.17194 (18) | 0.0259 (2) | |
H10 | −0.1702 | 0.0196 | 0.2894 | 0.031* | |
C11 | 0.20546 (18) | 0.02380 (4) | −0.00674 (18) | 0.0254 (2) | |
H11 | 0.3453 | 0.0401 | −0.0122 | 0.030* |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.0364 (6) | 0.0409 (6) | 0.0340 (5) | −0.0050 (4) | 0.0129 (4) | 0.0008 (4) |
C1 | 0.0345 (6) | 0.0402 (7) | 0.0532 (8) | −0.0114 (5) | 0.0095 (6) | 0.0025 (6) |
N2 | 0.0260 (5) | 0.0295 (5) | 0.0272 (5) | −0.0033 (4) | 0.0044 (4) | −0.0064 (4) |
C2 | 0.0428 (7) | 0.0273 (6) | 0.0400 (7) | −0.0030 (5) | −0.0081 (5) | −0.0037 (5) |
C3 | 0.0552 (8) | 0.0312 (6) | 0.0266 (6) | 0.0043 (5) | 0.0089 (5) | −0.0037 (5) |
C4 | 0.0354 (6) | 0.0288 (5) | 0.0317 (6) | −0.0010 (5) | 0.0131 (5) | −0.0008 (4) |
C5 | 0.0249 (5) | 0.0240 (5) | 0.0242 (5) | 0.0031 (4) | 0.0025 (4) | 0.0002 (4) |
C6 | 0.0342 (6) | 0.0275 (6) | 0.0311 (6) | 0.0025 (5) | 0.0000 (5) | −0.0061 (4) |
C7 | 0.0257 (5) | 0.0278 (5) | 0.0296 (5) | −0.0019 (4) | 0.0045 (4) | −0.0074 (4) |
C8 | 0.0244 (5) | 0.0252 (5) | 0.0250 (5) | 0.0007 (4) | 0.0056 (4) | −0.0027 (4) |
C9 | 0.0219 (5) | 0.0217 (5) | 0.0239 (5) | 0.0004 (4) | 0.0034 (4) | −0.0009 (4) |
C10 | 0.0252 (5) | 0.0284 (5) | 0.0252 (5) | −0.0010 (4) | 0.0088 (4) | −0.0026 (4) |
C11 | 0.0214 (5) | 0.0262 (5) | 0.0289 (5) | −0.0030 (4) | 0.0073 (4) | −0.0014 (4) |
N1—C5 | 1.3344 (15) | C6—C7 | 1.5204 (16) |
N1—C1 | 1.3395 (17) | C6—H6A | 0.9900 |
C1—C2 | 1.372 (2) | C6—H6B | 0.9900 |
C1—H1 | 0.9500 | C7—H7A | 0.9900 |
N2—C8 | 1.2628 (14) | C7—H7B | 0.9900 |
N2—C7 | 1.4609 (13) | C8—C9 | 1.4748 (14) |
C2—C3 | 1.3739 (19) | C8—H8 | 0.9500 |
C2—H2 | 0.9500 | C9—C11 | 1.3954 (14) |
C3—C4 | 1.3811 (17) | C9—C10 | 1.3968 (14) |
C3—H3 | 0.9500 | C10—C11i | 1.3848 (14) |
C4—C5 | 1.3880 (15) | C10—H10 | 0.9500 |
C4—H4 | 0.9500 | C11—C10i | 1.3848 (14) |
C5—C6 | 1.5023 (15) | C11—H11 | 0.9500 |
C5—N1—C1 | 117.33 (10) | C7—C6—H6B | 109.0 |
N1—C1—C2 | 124.19 (12) | H6A—C6—H6B | 107.8 |
N1—C1—H1 | 117.9 | N2—C7—C6 | 109.03 (9) |
C2—C1—H1 | 117.9 | N2—C7—H7A | 109.9 |
C8—N2—C7 | 117.17 (9) | C6—C7—H7A | 109.9 |
C1—C2—C3 | 118.02 (11) | N2—C7—H7B | 109.9 |
C1—C2—H2 | 121.0 | C6—C7—H7B | 109.9 |
C3—C2—H2 | 121.0 | H7A—C7—H7B | 108.3 |
C2—C3—C4 | 119.10 (11) | N2—C8—C9 | 122.66 (9) |
C2—C3—H3 | 120.4 | N2—C8—H8 | 118.7 |
C4—C3—H3 | 120.4 | C9—C8—H8 | 118.7 |
C3—C4—C5 | 119.07 (11) | C11—C9—C10 | 119.15 (9) |
C3—C4—H4 | 120.5 | C11—C9—C8 | 121.17 (9) |
C5—C4—H4 | 120.5 | C10—C9—C8 | 119.68 (9) |
N1—C5—C4 | 122.27 (10) | C11i—C10—C9 | 120.70 (9) |
N1—C5—C6 | 116.12 (10) | C11i—C10—H10 | 119.6 |
C4—C5—C6 | 121.60 (10) | C9—C10—H10 | 119.6 |
C5—C6—C7 | 113.13 (9) | C10i—C11—C9 | 120.15 (9) |
C5—C6—H6A | 109.0 | C10i—C11—H11 | 119.9 |
C7—C6—H6A | 109.0 | C9—C11—H11 | 119.9 |
C5—C6—H6B | 109.0 | ||
C5—N1—C1—C2 | −0.4 (2) | C8—N2—C7—C6 | 111.41 (11) |
N1—C1—C2—C3 | 0.9 (2) | C5—C6—C7—N2 | 167.84 (9) |
C1—C2—C3—C4 | −1.10 (19) | C7—N2—C8—C9 | −179.14 (9) |
C2—C3—C4—C5 | 0.83 (18) | N2—C8—C9—C11 | −2.76 (16) |
C1—N1—C5—C4 | 0.06 (17) | N2—C8—C9—C10 | 177.48 (10) |
C1—N1—C5—C6 | −179.64 (10) | C11—C9—C10—C11i | 0.57 (17) |
C3—C4—C5—N1 | −0.30 (17) | C8—C9—C10—C11i | −179.67 (9) |
C3—C4—C5—C6 | 179.39 (10) | C10—C9—C11—C10i | −0.57 (17) |
N1—C5—C6—C7 | −94.33 (12) | C8—C9—C11—C10i | 179.68 (9) |
C4—C5—C6—C7 | 85.97 (13) |
Symmetry code: (i) −x, −y, −z. |
Cg1 and Cg2 are the centroids of the C1–C5/N1 and C9–C11/C9'–C11' rings, respectively. |
D—H···A | D—H | H···A | D···A | D—H···A |
C3—H3···N1ii | 0.95 | 2.74 | 3.544 (3) | 143 (3) |
C4—H4···N2ii | 0.95 | 2.69 | 3.593 (2) | 159 (4) |
C7—H7A···N1iii | 0.99 | 2.87 | 3.847 (2) | 171 (5) |
C2—H2···Cg1iv | 0.95 | 2.88 | 3.826 (4) | 172 (5) |
C6—H6A···Cg2v | 0.99 | 2.90 | 3.508 (3) | 120 (2) |
Symmetry codes: (ii) x, y, z+1; (iii) x−1, y, z; (iv) x+1/2, −y+1/2, z+1/2; (v) x+1, y, z+1. |
Experimental details
Crystal data | |
Chemical formula | C22H22N4 |
Mr | 342.44 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 173 |
a, b, c (Å) | 6.0078 (6), 26.023 (3), 6.1319 (7) |
β (°) | 106.009 (2) |
V (Å3) | 921.47 (17) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.26 × 0.24 × 0.17 |
Data collection | |
Diffractometer | Bruker Kappa DUO APEXII diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 11941, 2288, 1945 |
Rint | 0.024 |
(sin θ/λ)max (Å−1) | 0.668 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.040, 0.110, 1.06 |
No. of reflections | 2288 |
No. of parameters | 118 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.28, −0.20 |
Computer programs: APEX2 (Bruker, 2006), SAINT (Bruker, 2006), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001), publCIF (Westrip, 2010).
Cg1 and Cg2 are the centroids of the C1–C5/N1 and C9–C11/C9'–C11' rings, respectively. |
D—H···A | D—H | H···A | D···A | D—H···A |
C3—H3···N1i | 0.95 | 2.74 | 3.544 (3) | 143 (3) |
C4—H4···N2i | 0.95 | 2.69 | 3.593 (2) | 159 (4) |
C7—H7A···N1ii | 0.99 | 2.87 | 3.847 (2) | 171 (5) |
C2—H2···Cg1iii | 0.95 | 2.88 | 3.826 (4) | 172 (5) |
C6—H6A···Cg2iv | 0.99 | 2.90 | 3.508 (3) | 120 (2) |
Symmetry codes: (i) x, y, z+1; (ii) x−1, y, z; (iii) x+1/2, −y+1/2, z+1/2; (iv) x+1, y, z+1. |
Acknowledgements
We gratefully acknowledge Mintek and Project AuTEK for funding this project.
References
Barbour, L. J. (2001). J. Supramol. Chem. 1, 189–191. CrossRef CAS Google Scholar
Bruker (2006). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Chakraborty, S., Munshi, P. & Lahiri, G. K. (1999). Polyhedron, 18, 1437–1444. Web of Science CrossRef CAS Google Scholar
Haga, M. & Koizumi, K. (1985). Inorg. Chim. Acta, 104, 47–50. CrossRef CAS Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar
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This work originates from our interest in developing a new class of tetradentate ligands. To the best of our knowledge, this work demonstrates the first example of neutral pyridinyldimine-based bridging ligand. The title compound might be expected to behave as a tetradentate chelating agent, in which both of the N atoms from the imine might coordinate, along with the two pyridinyl N atoms. Chakraborty et al. (1999) reported coordination of similar ligands to ruthenium whilst Haga and Koizumi (1985) reported their coordination to molybdenum. The structure of the title compound crystallized in space group P21/n with Z = 2. The molecule, shown in Fig. 1, has a center of inversion at the centroid of the benzene ring and was located in special positions at Wyckoff positon a. The conformation of the molecule is best described by the dihedral angle of the central ring and pyridyl ring of 10.94 (5)°. The structure is stabilized by weak hydrogen bonds of the type C—H···N and C—H···π, the metrics of which are given in Table 1. The C—H···N intermolecular interactions, as well as C6—H6A···Ring 1 (of C10—C9—C11—C10'-C9'-C11'), connect the parallel neighbouring molecules into 2-dimentional layers. And these layers are then linked along the b axis into 3-dimentional herringbone packing via C2—H2···Ring 2 (of C1—C2—C3—C4—C5—N1) interactions, as shown in Fig.2.