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Acta Crystallogr Sect E Struct Rep Online. 2008 November 1; 64(Pt 11): o2237.
Published online 2008 October 31. doi:  10.1107/S1600536808033904
PMCID: PMC2959583

N,N′-Dibenzyl-2,2′-[(1,3,4-oxadiazole-2,5-di­yl)bis­(o-phenyl­eneoxy)]diacet­amide

Abstract

The compound, C32H28N4O5, which was synthesized by the reaction of 2,5-bis­(2-hydroxy­lphen­yl)-1,3,4-oxadiazole with N-benzyl-2-chloro­acetamide, lies on a twofold rotation axis which passes through the mid-point of the N—N bond and the O atom of the oxadiazole unit. The phenyl­ene and oxadiazole rings are almost coplanar [dihedral angle 1.67 (5)°]. The structure is stabilized by intra­molecular N—H(...)O and N—H(...)N hydrogen bonds.

Related literature

For the biological and physical properties of 1,3,4-oxadiazole derivatives, see Gómez-Saiz et al. (2002 [triangle]); Wen et al. (2003 [triangle]); Kuo et al. (2006 [triangle]). For literature on metal complexes, see Dong et al. (2003 [triangle]); Zhou et al. (1996 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-64-o2237-scheme1.jpg

Experimental

Crystal data

  • C32H28N4O5
  • M r = 548.58
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-64-o2237-efi1.jpg
  • a = 17.0619 (15) Å
  • b = 15.2601 (15) Å
  • c = 10.6555 (9) Å
  • β = 90.611 (5)°
  • V = 2774.2 (4) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.09 mm−1
  • T = 293 (2) K
  • 0.53 × 0.40 × 0.30 mm

Data collection

  • Bruker APEXII diffractometer
  • Absorption correction: none
  • 7913 measured reflections
  • 2880 independent reflections
  • 2335 reflections with I > 2σ(I)
  • R int = 0.022

Refinement

  • R[F 2 > 2σ(F 2)] = 0.041
  • wR(F 2) = 0.158
  • S = 1.17
  • 2880 reflections
  • 187 parameters
  • H-atom parameters constrained
  • Δρmax = 0.18 e Å−3
  • Δρmin = −0.13 e Å−3

Data collection: APEX2 (Bruker, 2001 [triangle]); cell refinement: SAINT (Bruker, 2001 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: SHELXTL (Sheldrick, 2008 [triangle]); software used to prepare material for publication: SHELXTL.

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808033904/ng2497sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808033904/ng2497Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

The authors acknowledge financial support from the National Natural Science Foundation of China (grant No. 20571035) and the Interdisciplinary Innovation Research Fund for Young Scholars, Lanzhou University (grant No. LZU200506).

supplementary crystallographic information

Comment

Heterocyclic 1,3,4-oxadiazole and its derivatives have been studied for a long time because many of these derivatives show biological activity (Patricia et al., 2002) and electron-transporting capability (Wen et al., 2003), in particular as active compounds in organic light emitting diodes (OLEDs) (Kuo et al., 2006). At the same time, these five-membered oxadiazole ring can bind metal ions by N and O donors to expand various novel polymeric frameworks, some with open channels and interesting luminescence properties (Dong et al., 2003). We herein report the synthesis and crystal structure of a new amide-based 1,3,4-oxadiazole bridging ligand, namely the title compound, (I).

As seen from Fig. 1, the molecule of (I) possesses crystallographically imposed C2 symmetry, with the two fold axis bisecting the central 1,3,4-oxadiazole ring. The central two phenyl rings and oxadiazole ring are almost coplanar. The amide groups of molecule appear to form intramolecular hydrogen bonds with both the phenoxy O atom and the oxadiazole N atom (Table 1). In addition, the centroid-to-centroid distance (4.344 Å) of the two terminal benzene rings is so much longer that it is difficult to regard this as representing a significantly π-π stacking interaction.

Experimental

To 2,5-bis[2'-hydroxyl-phenyl]-1,3,4-oxadiazole (Zhou et al., 1996) (1.78 g, 7 mmol) in DMF (80 ml) was added sodium hydroxide (0.56 g, 14 mmol). The mixture was heated to 353 K and stirred for about 1 h. A solution of N-benzyl-2-chloroacetamide (2.94 g, 16 mmol) and potassium iodide (0.83 g, 5 mmol) in DMF (20 ml) was then added dropwise at a constant rate over 1 h. The reaction mixture was stirred at ca 353 K for an additional 48 h. The solvent was removed under vacuum, and then the residue was treated with water (100 ml). The precipitate was collected by filtration and washed with water (100 ml), then twice recrystallized from methanol to give colourless block crystals. 1H NMR (400M Hz; CDCl3, δ, p.p.m): 9.19 (t, 2H, N—H, J = 6 Hz), 8.04 (d, 2H, Ar—H, J = 8 Hz), 7.58 (t, 2H, Ar—H, J = 8 Hz), 7.24–7.15 (m, 12H, Ar—H), 7.06 (d, 2H, Ar—H, J = 8 Hz), 4.72 (s, 4H, O—CH2), 4.32 (d, 4H, Ar—CH2—N, J= 6 Hz); Yield 2.30 g (60%); m.p. 462–464 K; elemental analysis, calculated for C32H28N4O5, C 70.06, H 5.14, N 10.21%; found: C 70.18, H 5.02, N 10.22%. Colourless single crystals suitable for an X-ray diffraction study were obtained by slow evaporation of the methanol solvent at room temperature over a period of 5 d.

Refinement

All H atoms were initially located in a difference Fourier map and refined freely along with an isotropic displacement parameter. H atoms were positioned geometrically and treated as riding, with C—H = 0.93 and 0.97%A, N—H = 0.86%A,and Uiso(H) = 1.2Ueq(C,N).

Figures

Fig. 1.
The structure of the title compound, showing 20% probability displacement ellipsoids and the atom-labelling scheme. The intramolecular hydrogen bonds are shown as dashed lines.

Crystal data

C32H28N4O5F(000) = 1152
Mr = 548.58Dx = 1.313 Mg m3
Monoclinic, C2/cMelting point: 462 K
Hall symbol: -C2ycMo Kα radiation, λ = 0.71073 Å
a = 17.0619 (15) ÅCell parameters from 3319 reflections
b = 15.2601 (15) Åθ = 2.4–27.5°
c = 10.6555 (9) ŵ = 0.09 mm1
β = 90.611 (5)°T = 293 K
V = 2774.2 (4) Å3Block, colourless
Z = 40.53 × 0.40 × 0.30 mm

Data collection

Bruker APEXII diffractometer2335 reflections with I > 2σ(I)
Radiation source: sealed tubeRint = 0.022
graphiteθmax = 26.5°, θmin = 1.8°
[var phi] and ω scansh = −21→20
7913 measured reflectionsk = −12→19
2880 independent reflectionsl = −13→12

Refinement

Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.041H-atom parameters constrained
wR(F2) = 0.158w = 1/[σ2(Fo2) + (0.1P)2] where P = (Fo2 + 2Fc2)/3
S = 1.17(Δ/σ)max = 0.001
2880 reflectionsΔρmax = 0.18 e Å3
187 parametersΔρmin = −0.13 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: 0.0054 (10)

Special details

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)

xyzUiso*/Ueq
O10.50001.06829 (8)0.75000.0488 (3)
O20.37163 (7)0.91715 (7)0.50427 (11)0.0724 (4)
O30.32801 (7)0.70855 (8)0.38437 (12)0.0822 (4)
N10.47305 (7)0.93150 (7)0.69949 (10)0.0494 (3)
N20.41511 (7)0.75799 (8)0.52944 (11)0.0586 (3)
H2A0.43170.80250.57140.070*
C10.45891 (7)1.01308 (8)0.67330 (11)0.0443 (3)
C20.40733 (7)1.05489 (9)0.58052 (11)0.0466 (3)
C30.40137 (9)1.14557 (10)0.57514 (13)0.0580 (4)
H3A0.43071.17960.63080.070*
C40.35278 (9)1.18603 (10)0.48861 (15)0.0677 (4)
H4A0.34931.24680.48650.081*
C50.30953 (9)1.13641 (11)0.40562 (15)0.0650 (4)
H5A0.27721.16390.34690.078*
C60.31367 (8)1.04601 (10)0.40866 (14)0.0582 (4)
H6A0.28391.01270.35280.070*
C70.36253 (7)1.00528 (9)0.49553 (11)0.0496 (3)
C80.32734 (8)0.86010 (9)0.42649 (13)0.0560 (4)
H8A0.33280.87700.33920.067*
H8B0.27230.86330.44800.067*
C90.35711 (8)0.76851 (9)0.44569 (13)0.0558 (4)
C100.45065 (9)0.67305 (10)0.55103 (16)0.0654 (4)
H10A0.50400.68200.58090.078*
H10B0.45340.64240.47140.078*
C110.40855 (7)0.61462 (8)0.64410 (12)0.0508 (3)
C120.41917 (10)0.52501 (10)0.63923 (16)0.0682 (4)
H12A0.45000.50130.57620.082*
C130.38524 (10)0.46989 (11)0.72545 (16)0.0738 (5)
H13A0.39370.40980.72090.089*
C140.33913 (10)0.50362 (12)0.81753 (14)0.0709 (5)
H14A0.31680.46680.87680.085*
C150.32603 (11)0.59234 (12)0.82183 (15)0.0785 (5)
H15A0.29370.61560.88320.094*
C160.36072 (10)0.64747 (10)0.73521 (14)0.0666 (4)
H16A0.35140.70750.73900.080*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
O10.0557 (7)0.0377 (7)0.0528 (7)0.000−0.0038 (6)0.000
O20.0861 (8)0.0440 (6)0.0862 (8)0.0010 (5)−0.0371 (6)−0.0052 (5)
O30.0976 (9)0.0571 (8)0.0913 (8)−0.0035 (6)−0.0217 (7)−0.0175 (6)
N10.0536 (6)0.0409 (6)0.0537 (6)−0.0004 (5)−0.0055 (5)−0.0002 (4)
N20.0599 (7)0.0475 (7)0.0682 (8)−0.0027 (5)−0.0049 (6)0.0025 (5)
C10.0460 (6)0.0409 (7)0.0461 (7)−0.0030 (5)0.0036 (5)−0.0002 (5)
C20.0466 (7)0.0435 (7)0.0496 (7)−0.0019 (5)0.0049 (5)0.0055 (5)
C30.0656 (8)0.0450 (8)0.0632 (9)−0.0054 (6)−0.0017 (7)0.0075 (6)
C40.0776 (10)0.0459 (8)0.0794 (11)0.0010 (7)−0.0042 (8)0.0185 (7)
C50.0630 (9)0.0619 (10)0.0699 (9)0.0028 (7)−0.0057 (7)0.0227 (7)
C60.0556 (8)0.0609 (9)0.0581 (8)−0.0002 (6)−0.0055 (6)0.0075 (6)
C70.0506 (7)0.0446 (7)0.0536 (7)−0.0002 (6)0.0006 (6)0.0047 (5)
C80.0567 (7)0.0526 (9)0.0584 (8)−0.0057 (6)−0.0091 (6)−0.0043 (6)
C90.0578 (8)0.0503 (8)0.0593 (8)−0.0043 (6)0.0004 (6)−0.0044 (6)
C100.0572 (8)0.0597 (10)0.0794 (10)0.0068 (7)0.0053 (7)0.0083 (7)
C110.0485 (7)0.0522 (8)0.0516 (7)0.0032 (6)−0.0073 (5)−0.0003 (5)
C120.0724 (10)0.0589 (9)0.0734 (10)0.0188 (7)0.0086 (8)0.0065 (7)
C130.0816 (11)0.0548 (9)0.0850 (12)0.0083 (8)−0.0040 (9)0.0156 (8)
C140.0796 (10)0.0749 (11)0.0581 (9)−0.0146 (9)−0.0069 (8)0.0125 (7)
C150.0893 (12)0.0861 (13)0.0603 (10)−0.0136 (10)0.0152 (9)−0.0130 (8)
C160.0819 (10)0.0534 (8)0.0644 (9)−0.0039 (7)0.0056 (7)−0.0143 (7)

Geometric parameters (Å, °)

O1—C11.3627 (14)C6—C71.3863 (18)
O1—C1i1.3627 (14)C6—H6A0.9300
O2—C71.3570 (16)C8—C91.500 (2)
O2—C81.4151 (16)C8—H8A0.9700
O3—C91.2262 (17)C8—H8B0.9700
N1—C11.2979 (16)C10—C111.5197 (19)
N1—N1i1.408 (2)C10—H10A0.9700
N2—C91.3352 (19)C10—H10B0.9700
N2—C101.4484 (19)C11—C161.3699 (19)
N2—H2A0.8600C11—C121.3805 (19)
C1—C21.4630 (16)C12—C131.378 (2)
C2—C31.389 (2)C12—H12A0.9300
C2—C71.4009 (17)C13—C141.365 (2)
C3—C41.379 (2)C13—H13A0.9300
C3—H3A0.9300C14—C151.373 (2)
C4—C51.373 (2)C14—H14A0.9300
C4—H4A0.9300C15—C161.386 (2)
C5—C61.382 (2)C15—H15A0.9300
C5—H5A0.9300C16—H16A0.9300
C1—O1—C1i103.62 (13)O2—C8—H8B110.0
C7—O2—C8120.64 (11)C9—C8—H8B110.0
C1—N1—N1i106.43 (7)H8A—C8—H8B108.4
C9—N2—C10121.32 (13)O3—C9—N2124.01 (14)
C9—N2—H2A119.3O3—C9—C8119.20 (14)
C10—N2—H2A119.3N2—C9—C8116.78 (12)
N1—C1—O1111.76 (11)N2—C10—C11115.39 (11)
N1—C1—C2132.28 (12)N2—C10—H10A108.4
O1—C1—C2115.95 (11)C11—C10—H10A108.4
C3—C2—C7118.20 (12)N2—C10—H10B108.4
C3—C2—C1120.38 (12)C11—C10—H10B108.4
C7—C2—C1121.42 (12)H10A—C10—H10B107.5
C4—C3—C2121.12 (14)C16—C11—C12117.94 (13)
C4—C3—H3A119.4C16—C11—C10122.48 (13)
C2—C3—H3A119.4C12—C11—C10119.57 (12)
C5—C4—C3119.91 (15)C13—C12—C11121.56 (14)
C5—C4—H4A120.0C13—C12—H12A119.2
C3—C4—H4A120.0C11—C12—H12A119.2
C4—C5—C6120.56 (14)C14—C13—C12119.91 (16)
C4—C5—H5A119.7C14—C13—H13A120.0
C6—C5—H5A119.7C12—C13—H13A120.0
C5—C6—C7119.57 (14)C13—C14—C15119.41 (14)
C5—C6—H6A120.2C13—C14—H14A120.3
C7—C6—H6A120.2C15—C14—H14A120.3
O2—C7—C6123.90 (12)C14—C15—C16120.36 (15)
O2—C7—C2115.47 (11)C14—C15—H15A119.8
C6—C7—C2120.63 (13)C16—C15—H15A119.8
O2—C8—C9108.39 (12)C11—C16—C15120.77 (15)
O2—C8—H8A110.0C11—C16—H16A119.6
C9—C8—H8A110.0C15—C16—H16A119.6

Symmetry codes: (i) −x+1, y, −z+3/2.

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N2—H2A···O20.862.152.5523 (16)109
N2—H2A···N10.862.493.3524 (17)177

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: NG2497).

References

  • Bruker (2001). APEX2 and SAINT Bruker AXS Inc., Madison, Wisconsin, USA.
  • Dong, Y.-B., Cheng, J.-Y. & Huang, R.-Q. (2003). Inorg. Chem.42, 5699–5706. [PubMed]
  • Kuo, C.-H., Peng, K.-C., Kuo, L.-C., Yang, K. H., Lee, J.-H., Leung, M.-K. & Hsieh, K.-H. (2006). Chem. Mater.18, 4121–4129.
  • Gómez-Saiz, P., García-Tojal, J., Maestro, M. A., Arnaiz, F. J. & Rojo, T. (2002). Inorg. Chem.41, 1345–1347. [PubMed]
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Wen, C.-R., Wang, Y.-J., Wang, H.-C., Sheu, H.-S., Lee, G.-H. & Lai, C. K. (2003). Chem. Mater.17, 1646–1654.
  • Zhou, J.-M., Hua, W.-T. & Yang, Q.-C. (1996). Chem. J. Chin. Univ.17, 1721–1724.

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