organic compounds
5-Nitro-2,3-bis(thiophen-2-yl)quinoxaline
aDepartment of Chemistry & Biochemistry, Central Connecticut State University, 1619 Stanley Street, New Britain, CT 06053, USA
*Correspondence e-mail: crundwellg@ccsu.edu
The title compound, C16H9N3O2S2, was synthesized via a condensation reaction in refluxing acetic acid. The dihedral angles between the mean plane of the quinoxaline unit and the thienyl rings are 35.16 (5)° and 24.94 (3)°.
Keywords: crystal structure; quinoxaline; thiophene.
CCDC reference: 1983314
Structure description
5-Nitro-2,3-bis(thiophen-2-yl)quinoxaline crystallizes in P21. All bond lengths and angles are within expected values. The nitro group makes a angle of 43.07 (6)° with respect to the mean plane of the quinoxaline unit. This angle is comparable to the angles of 44.96 and 50.93° observed for the two molecules in the in the published of 5-nitro-2,3-bis(2-pyridyl)quinoxaline (Du & Zhao, 2003) and with the 44.12° determined in a corresponding silver complex with the pyridyl ligand (Liu & Du, 2002). The thienyl rings make angles of 35.16 (5) and 24.94 (3)°, for rings with S1 and S2 respectively, with the mean plane of the quinoxaline unit. Both the heterocyclic thienyl ring sulfur atoms reside in close proximity to the quinoxaline N atoms. When describing the structure of 5-nitro-2,3-bis(2-pyridyl)quinoxaline, Du & Zhao (2003) labeled this orientation of the heterocyclic ring to the quinoxaline unit as a trans–trans arrangement. There are no intermolecular interactions of consequence. An ORTEP view is shown in Fig. 1 and a view of the along (010) is shown in Fig. 2.
Synthesis and crystallization
2-Thiophenecarboxaldehyde was condensed to 2,2′-thenoin (Crundwell et al., 2002) followed by oxidation to 2,2′-thenil (Crundwell et al., 2003). The nitrophenylenediamines were used as purchased from Sigma–Aldrich.
In a 100 ml round-bottom flask, 2.22 g of 2,2′-thenil (10.0 mmol) and 1.52 g of 3-nitro-1,2-phenylenediamine were added to 50 ml of concentrated acetic acid. The solution was refluxed with stirring for 18 h. The solution was cooled to room temperature and neutralized with 6 M NaOH. The solution was again cooled then filtered. The resulting solid was filtered and washed with cold water then dried. The yield of the yellow product was 2.80 g (83%), m.p. 445 K. Crystals were obtained by recrystallization from ethanol solution. 1H NMR (CDCl3, 300 MHz): δ = 7.17 (m, 2H), 7.42 (dd, 1H), 7.49 (dd, 1H), 7.80 (m, 2H), 7.97 (t, 1H), 8.30 (m, 2H); 13C NMR (CDCl3, 300 MHz): δ = 124.4, 127.7, 127.8, 128.8, 130.2, 130.3, 130.5, 131.0, 132.1, 132.8, 140.1, 140.5, 141.0, 147.0, 148.0, 148.1.
Refinement
Crystal data, data collection and structure .
details are summarized in Table 1Structural data
CCDC reference: 1983314
Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell
CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS2014 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: OLEX2 (Bourhis et al., 2015).C16H9N3O2S2 | Dx = 1.485 Mg m−3 |
Mr = 339.38 | Melting point: 445 K |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
a = 9.6598 (4) Å | Cell parameters from 4761 reflections |
b = 7.4249 (3) Å | θ = 4.2–34.7° |
c = 11.2457 (6) Å | µ = 0.36 mm−1 |
β = 109.745 (5)° | T = 293 K |
V = 759.15 (6) Å3 | Block, yellow |
Z = 2 | 0.42 × 0.34 × 0.21 mm |
F(000) = 348 |
Oxford Diffraction Xcalibur, Sapphire3 diffractometer | 6073 independent reflections |
Radiation source: Enhance (Mo) X-ray Source | 3455 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.021 |
Detector resolution: 16.1790 pixels mm-1 | θmax = 34.7°, θmin = 4.2° |
ω scans | h = −14→15 |
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009) | k = −11→11 |
Tmin = 0.865, Tmax = 1.000 | l = −17→17 |
12526 measured reflections |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.038 | H-atom parameters constrained |
wR(F2) = 0.076 | w = 1/[σ2(Fo2) + (0.0401P)2] where P = (Fo2 + 2Fc2)/3 |
S = 0.81 | (Δ/σ)max < 0.001 |
6073 reflections | Δρmax = 0.43 e Å−3 |
208 parameters | Δρmin = −0.15 e Å−3 |
1 restraint | Absolute structure: Flack (1983) |
Primary atom site location: iterative | Absolute structure parameter: 0.02 (4) |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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. H atoms were included in calculated positions with C-H distances of 0.93 Å and were included in the refinement in riding motion approximation with Uiso = 1.2 of the carrier atom. |
x | y | z | Uiso*/Ueq | ||
S1 | 0.47899 (5) | 0.46766 (7) | 0.76512 (4) | 0.06021 (14) | |
S2 | −0.19846 (4) | 0.56574 (5) | 0.45980 (4) | 0.04714 (10) | |
O1 | −0.14872 (15) | 0.6115 (2) | 0.11787 (12) | 0.0794 (4) | |
O2 | −0.12755 (18) | 0.3929 (3) | 0.00033 (12) | 0.0978 (6) | |
N1 | 0.33895 (13) | 0.50828 (18) | 0.48400 (11) | 0.0434 (3) | |
N2 | 0.03464 (12) | 0.50012 (16) | 0.35820 (10) | 0.0368 (3) | |
N3 | −0.07726 (18) | 0.4977 (3) | 0.08793 (12) | 0.0608 (4) | |
C1 | 0.24643 (14) | 0.52968 (18) | 0.54672 (12) | 0.0358 (3) | |
C2 | 0.08928 (14) | 0.51352 (17) | 0.48202 (12) | 0.0324 (3) | |
C3 | 0.13010 (16) | 0.4937 (2) | 0.29286 (13) | 0.0390 (3) | |
C4 | 0.08067 (17) | 0.4805 (2) | 0.16013 (13) | 0.0473 (4) | |
C5 | 0.1750 (2) | 0.4561 (3) | 0.09426 (17) | 0.0645 (5) | |
H5 | 0.1394 | 0.4464 | 0.0067 | 0.077* | |
C6 | 0.3257 (2) | 0.4459 (3) | 0.16079 (18) | 0.0727 (6) | |
H6 | 0.3903 | 0.4287 | 0.1164 | 0.087* | |
C7 | 0.3801 (2) | 0.4603 (3) | 0.28792 (17) | 0.0647 (5) | |
H7 | 0.4811 | 0.4537 | 0.3299 | 0.078* | |
C8 | 0.28385 (16) | 0.4853 (2) | 0.35731 (14) | 0.0435 (3) | |
C9 | 0.31323 (14) | 0.5671 (2) | 0.68209 (12) | 0.0378 (3) | |
C10 | 0.26900 (17) | 0.6793 (2) | 0.75847 (14) | 0.0447 (4) | |
H10 | 0.1831 | 0.7472 | 0.7308 | 0.054* | |
C11 | 0.36745 (19) | 0.6812 (2) | 0.88351 (15) | 0.0554 (4) | |
H11 | 0.3529 | 0.7491 | 0.9478 | 0.066* | |
C12 | 0.48426 (19) | 0.5748 (3) | 0.90005 (15) | 0.0630 (5) | |
H12 | 0.5599 | 0.5610 | 0.9769 | 0.076* | |
C13 | −0.02054 (14) | 0.50573 (18) | 0.54585 (12) | 0.0332 (3) | |
C14 | −0.01082 (17) | 0.4470 (2) | 0.66529 (14) | 0.0452 (4) | |
H14 | 0.0756 | 0.4075 | 0.7262 | 0.054* | |
C15 | −0.1486 (2) | 0.4545 (3) | 0.68296 (16) | 0.0554 (4) | |
H15 | −0.1625 | 0.4191 | 0.7574 | 0.066* | |
C16 | −0.25747 (19) | 0.5175 (2) | 0.58246 (17) | 0.0552 (5) | |
H16 | −0.3539 | 0.5329 | 0.5802 | 0.066* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0398 (2) | 0.0812 (3) | 0.0524 (2) | 0.0186 (2) | 0.00605 (16) | 0.0062 (2) |
S2 | 0.03174 (17) | 0.0601 (2) | 0.0503 (2) | 0.00166 (19) | 0.01476 (14) | −0.0002 (2) |
O1 | 0.0607 (8) | 0.1124 (12) | 0.0540 (8) | 0.0145 (9) | 0.0049 (6) | −0.0004 (8) |
O2 | 0.0919 (11) | 0.1455 (15) | 0.0512 (8) | −0.0414 (11) | 0.0180 (7) | −0.0355 (9) |
N1 | 0.0313 (5) | 0.0576 (8) | 0.0441 (7) | 0.0034 (5) | 0.0163 (5) | 0.0023 (6) |
N2 | 0.0324 (5) | 0.0459 (7) | 0.0336 (6) | −0.0032 (5) | 0.0130 (4) | −0.0010 (5) |
N3 | 0.0650 (9) | 0.0883 (11) | 0.0270 (6) | −0.0192 (9) | 0.0130 (6) | −0.0009 (7) |
C1 | 0.0309 (6) | 0.0381 (9) | 0.0380 (7) | 0.0006 (5) | 0.0110 (5) | 0.0010 (6) |
C2 | 0.0299 (6) | 0.0335 (7) | 0.0359 (7) | 0.0008 (5) | 0.0137 (5) | 0.0011 (5) |
C3 | 0.0416 (7) | 0.0408 (7) | 0.0388 (7) | −0.0044 (7) | 0.0193 (6) | −0.0011 (6) |
C4 | 0.0517 (9) | 0.0560 (9) | 0.0362 (7) | −0.0060 (8) | 0.0172 (6) | −0.0046 (7) |
C5 | 0.0788 (13) | 0.0810 (12) | 0.0454 (9) | −0.0026 (12) | 0.0363 (9) | −0.0057 (10) |
C6 | 0.0749 (13) | 0.0977 (15) | 0.0651 (12) | 0.0070 (12) | 0.0494 (11) | −0.0044 (11) |
C7 | 0.0481 (9) | 0.0942 (14) | 0.0624 (11) | 0.0057 (10) | 0.0326 (8) | −0.0038 (11) |
C8 | 0.0393 (7) | 0.0503 (8) | 0.0463 (8) | 0.0020 (7) | 0.0214 (6) | −0.0015 (7) |
C9 | 0.0300 (6) | 0.0451 (7) | 0.0361 (7) | 0.0024 (7) | 0.0085 (5) | 0.0068 (7) |
C10 | 0.0380 (8) | 0.0513 (9) | 0.0404 (8) | 0.0033 (7) | 0.0074 (6) | −0.0021 (7) |
C11 | 0.0552 (10) | 0.0658 (11) | 0.0422 (9) | −0.0047 (9) | 0.0126 (7) | −0.0075 (8) |
C12 | 0.0515 (9) | 0.0874 (13) | 0.0394 (8) | 0.0023 (11) | 0.0014 (7) | 0.0092 (10) |
C13 | 0.0286 (6) | 0.0369 (7) | 0.0355 (7) | −0.0008 (5) | 0.0125 (5) | −0.0013 (6) |
C14 | 0.0446 (8) | 0.0523 (9) | 0.0424 (8) | −0.0013 (8) | 0.0195 (6) | 0.0057 (7) |
C15 | 0.0598 (10) | 0.0686 (11) | 0.0483 (9) | −0.0147 (10) | 0.0321 (8) | −0.0071 (9) |
C16 | 0.0420 (8) | 0.0686 (12) | 0.0664 (11) | −0.0068 (8) | 0.0331 (8) | −0.0123 (9) |
S1—C9 | 1.7234 (14) | C5—C6 | 1.396 (3) |
S1—C12 | 1.6986 (19) | C6—H6 | 0.9300 |
S2—C13 | 1.7219 (14) | C6—C7 | 1.351 (2) |
S2—C16 | 1.6992 (17) | C7—H7 | 0.9300 |
O1—N3 | 1.209 (2) | C7—C8 | 1.414 (2) |
O2—N3 | 1.220 (2) | C9—C10 | 1.365 (2) |
N1—C1 | 1.3218 (17) | C10—H10 | 0.9300 |
N1—C8 | 1.3528 (19) | C10—C11 | 1.407 (2) |
N2—C2 | 1.3155 (17) | C11—H11 | 0.9300 |
N2—C3 | 1.3602 (17) | C11—C12 | 1.338 (2) |
N3—C4 | 1.472 (2) | C12—H12 | 0.9300 |
C1—C2 | 1.4498 (18) | C13—C14 | 1.3849 (19) |
C1—C9 | 1.4653 (19) | C14—H14 | 0.9300 |
C2—C13 | 1.4693 (18) | C14—C15 | 1.411 (2) |
C3—C4 | 1.409 (2) | C15—H15 | 0.9300 |
C3—C8 | 1.417 (2) | C15—C16 | 1.341 (3) |
C4—C5 | 1.367 (2) | C16—H16 | 0.9300 |
C5—H5 | 0.9300 | ||
C12—S1—C9 | 91.46 (8) | N1—C8—C3 | 120.30 (12) |
C16—S2—C13 | 91.95 (8) | N1—C8—C7 | 119.98 (14) |
C1—N1—C8 | 118.73 (12) | C3—C8—C7 | 119.66 (14) |
C2—N2—C3 | 118.14 (12) | C1—C9—S1 | 118.96 (11) |
O1—N3—O2 | 124.17 (17) | C10—C9—S1 | 110.59 (10) |
O1—N3—C4 | 119.36 (15) | C10—C9—C1 | 130.37 (13) |
O2—N3—C4 | 116.47 (19) | C9—C10—H10 | 123.7 |
N1—C1—C2 | 120.28 (12) | C9—C10—C11 | 112.66 (14) |
N1—C1—C9 | 115.93 (12) | C11—C10—H10 | 123.7 |
C2—C1—C9 | 123.78 (12) | C10—C11—H11 | 123.6 |
N2—C2—C1 | 121.01 (12) | C12—C11—C10 | 112.76 (15) |
N2—C2—C13 | 114.61 (11) | C12—C11—H11 | 123.6 |
C1—C2—C13 | 124.37 (12) | S1—C12—H12 | 123.7 |
N2—C3—C4 | 121.73 (13) | C11—C12—S1 | 112.51 (12) |
N2—C3—C8 | 120.66 (13) | C11—C12—H12 | 123.7 |
C8—C3—C4 | 117.41 (12) | C2—C13—S2 | 117.62 (10) |
C3—C4—N3 | 119.71 (13) | C14—C13—S2 | 110.76 (10) |
C5—C4—N3 | 117.98 (14) | C14—C13—C2 | 131.50 (13) |
C5—C4—C3 | 122.29 (15) | C13—C14—H14 | 124.3 |
C4—C5—H5 | 120.6 | C13—C14—C15 | 111.45 (14) |
C4—C5—C6 | 118.83 (16) | C15—C14—H14 | 124.3 |
C6—C5—H5 | 120.6 | C14—C15—H15 | 123.1 |
C5—C6—H6 | 119.1 | C16—C15—C14 | 113.81 (14) |
C7—C6—C5 | 121.71 (15) | C16—C15—H15 | 123.1 |
C7—C6—H6 | 119.1 | S2—C16—H16 | 124.0 |
C6—C7—H7 | 120.0 | C15—C16—S2 | 112.01 (12) |
C6—C7—C8 | 120.09 (17) | C15—C16—H16 | 124.0 |
C8—C7—H7 | 120.0 |
Funding information
This research was funded by a CCSU–AAUP research grant.
References
Bourhis, L. J., Dolomanov, O. V., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2015). Acta Cryst. A71, 59–75. Web of Science CrossRef IUCr Journals Google Scholar
Crundwell, G., Sullivan, J., Pelto, R. & Kantardjieff, K. (2003). J. Chem. Cryst, 33, 239–244. Web of Science CSD CrossRef CAS Google Scholar
Crundwell, G., Meskill, T., Sayers, D. & Kantardjieff, K. (2002). Acta Cryst. E58, o666–o667. Web of Science CSD CrossRef IUCr Journals Google Scholar
Du, M. & Zhao, X.-J. (2003). Acta Cryst. C59, o403–o405. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Liu, H. & Du, M. (2002). J. Mol. Struct. 607, 143–148. Web of Science CSD CrossRef CAS Google Scholar
Oxford Diffraction (2009). CrysAlis CCD, CrysAlis RED and CrysAlis PRO. Oxford Diffraction, Yarnton, England. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.