Acta Cryst. (2007). E63, o3887 [ doi:10.1107/S1600536807035362 ]
The title compound, C18H14N2O2, was prepared by recrystallization from the fluorescent brightener135. The almost perfectly planar molecule is located on a centre of inversion. The methyl H atoms are disordered equally over two positions.
The single crystals of the title compound were obtained by recrystalling the industrial product of the fluorescent whitener DT in ethanol and DMF 1:1 (v/v) for one week at room temperature.
H atoms were placed in calculated positions and treated using a riding model, with C—H = 0.93–0.98 Å and with Uiso(H) = 1.2Ueq(C) or 1.5Ueq(C) for methyl H atoms. The methyl group is disordered over two equally occupied positions.
Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software; data reduction: CAD-4 Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL/PC (Sheldrick, 1990); software used to prepare material for publication: SHELXTL/PC.
![[Figure 1]](./bt2434fig1thm.gif)
| Fig. 1. The molecular structure and atom-labeling scheme for (I), with displacement ellipsoids drawn at the 30% probability level. |
| C18H14N2O2 | Dx = 1.323 Mg m−3 |
| Mr = 290.31 | Melting point: 182 K |
| Monoclinic, C2/c | Mo Kα radiation λ = 0.71073 Å |
| a = 22.153 (4) Å | Cell parameters from 25 reflections |
| b = 4.7700 (10) Å | θ = 1.9–27.0º |
| c = 14.053 (3) Å | µ = 0.09 mm−1 |
| β = 100.94 (3)º | T = 293 (2) K |
| V = 1458.0 (5) Å3 | Needle, yellow |
| Z = 4 | 0.41 × 0.23 × 0.14 mm |
| F000 = 608 |
| Bruker P4 diffractometer | Rint = 0.037 |
| Radiation source: fine-focus sealed tube | θmax = 27.0º |
| Monochromator: graphite | θmin = 1.9º |
| T = 293(2) K | h = −27→26 |
| ω scans | k = −5→0 |
| Absorption correction: none | l = −16→16 |
| 3101 measured reflections | 3 standard reflections |
| 1560 independent reflections | every 200 reflections |
| 939 reflections with I > 2σ(I) | intensity decay: none |
| Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
| Least-squares matrix: full | H-atom parameters constrained |
| R[F2 > 2σ(F2)] = 0.055 | w = 1/[σ2(Fo2) + (0.0866P)2] where P = (Fo2 + 2Fc2)/3 |
| wR(F2) = 0.155 | (Δ/σ)max < 0.001 |
| S = 1.04 | Δρmax = 0.24 e Å−3 |
| 1560 reflections | Δρmin = −0.27 e Å−3 |
| 102 parameters | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
| Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0060 (17) |
| Secondary atom site location: difference Fourier map |
| C18H14N2O2 | V = 1458.0 (5) Å3 |
| Mr = 290.31 | Z = 4 |
| Monoclinic, C2/c | Mo Kα |
| a = 22.153 (4) Å | µ = 0.09 mm−1 |
| b = 4.7700 (10) Å | T = 293 (2) K |
| c = 14.053 (3) Å | 0.41 × 0.23 × 0.14 mm |
| β = 100.94 (3)º |
| Bruker P4 diffractometer | Rint = 0.037 |
| Absorption correction: none | 3 standard reflections |
| 3101 measured reflections | every 200 reflections |
| 1560 independent reflections | intensity decay: none |
| 939 reflections with I > 2σ(I) |
| R[F2 > 2σ(F2)] = 0.055 | 102 parameters |
| wR(F2) = 0.155 | H-atom parameters constrained |
| S = 1.04 | Δρmax = 0.24 e Å−3 |
| 1560 reflections | Δρmin = −0.27 e Å−3 |
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 > 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. |
| x | y | z | Uiso*/Ueq | Occ. (<1) | |
| O1 | 0.04467 (6) | 0.2073 (3) | 0.87972 (10) | 0.0425 (5) | |
| N1 | 0.10077 (8) | 0.0570 (4) | 1.02211 (13) | 0.0403 (5) | |
| C1 | 0.22548 (11) | −0.5999 (5) | 0.8526 (2) | 0.0560 (7) | |
| H1A | 0.2142 | −0.7097 | 0.7947 | 0.084* | 0.50 |
| H1B | 0.2303 | −0.7206 | 0.9082 | 0.084* | 0.50 |
| H1C | 0.2635 | −0.5049 | 0.8515 | 0.084* | 0.50 |
| H1D | 0.2579 | −0.5804 | 0.9082 | 0.084* | 0.50 |
| H1E | 0.2417 | −0.5695 | 0.7947 | 0.084* | 0.50 |
| H1F | 0.2085 | −0.7853 | 0.8514 | 0.084* | 0.50 |
| C2 | 0.17573 (10) | −0.3866 (4) | 0.85785 (17) | 0.0416 (6) | |
| C3 | 0.14015 (11) | −0.2845 (5) | 0.77202 (18) | 0.0480 (6) | |
| H3A | 0.1475 | −0.3536 | 0.7134 | 0.058* | |
| C4 | 0.09443 (11) | −0.0849 (5) | 0.77017 (17) | 0.0485 (6) | |
| H4A | 0.0710 | −0.0185 | 0.7126 | 0.058* | |
| C5 | 0.08615 (9) | 0.0078 (5) | 0.85917 (15) | 0.0375 (5) | |
| C6 | 0.11992 (9) | −0.0854 (4) | 0.94600 (15) | 0.0360 (5) | |
| C7 | 0.16546 (10) | −0.2896 (4) | 0.94564 (17) | 0.0413 (6) | |
| H7A | 0.1882 | −0.3580 | 1.0035 | 0.050* | |
| C8 | 0.05734 (10) | 0.2229 (5) | 0.97847 (16) | 0.0373 (5) | |
| C9 | 0.02220 (9) | 0.4192 (4) | 1.02433 (16) | 0.0402 (6) | |
| H9A | 0.0311 | 0.4336 | 1.0915 | 0.048* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| O1 | 0.0460 (9) | 0.0372 (9) | 0.0439 (9) | 0.0071 (7) | 0.0077 (6) | −0.0039 (7) |
| N1 | 0.0476 (11) | 0.0308 (10) | 0.0438 (10) | 0.0025 (9) | 0.0121 (8) | −0.0008 (8) |
| C1 | 0.0577 (15) | 0.0356 (13) | 0.0782 (19) | 0.0041 (12) | 0.0220 (13) | −0.0083 (12) |
| C2 | 0.0421 (12) | 0.0247 (11) | 0.0610 (15) | −0.0045 (10) | 0.0173 (11) | −0.0061 (10) |
| C3 | 0.0557 (14) | 0.0419 (14) | 0.0491 (14) | −0.0031 (12) | 0.0165 (11) | −0.0142 (11) |
| C4 | 0.0519 (14) | 0.0504 (15) | 0.0422 (13) | 0.0027 (12) | 0.0060 (10) | −0.0063 (11) |
| C5 | 0.0381 (11) | 0.0303 (12) | 0.0454 (12) | 0.0000 (10) | 0.0108 (9) | −0.0053 (10) |
| C6 | 0.0419 (12) | 0.0262 (11) | 0.0419 (12) | −0.0035 (10) | 0.0131 (9) | −0.0025 (9) |
| C7 | 0.0441 (12) | 0.0286 (12) | 0.0510 (14) | 0.0029 (10) | 0.0087 (10) | 0.0029 (10) |
| C8 | 0.0417 (11) | 0.0307 (11) | 0.0405 (12) | −0.0031 (10) | 0.0104 (9) | −0.0028 (10) |
| C9 | 0.0457 (13) | 0.0313 (12) | 0.0458 (13) | −0.0021 (10) | 0.0144 (10) | −0.0060 (9) |
| O1—C8 | 1.365 (3) | C2—C3 | 1.397 (3) |
| O1—C5 | 1.391 (2) | C3—C4 | 1.387 (3) |
| N1—C8 | 1.305 (3) | C3—H3A | 0.9300 |
| N1—C6 | 1.399 (3) | C4—C5 | 1.371 (3) |
| C1—C2 | 1.512 (3) | C4—H4A | 0.9300 |
| C1—H1A | 0.9600 | C5—C6 | 1.378 (3) |
| C1—H1B | 0.9600 | C6—C7 | 1.403 (3) |
| C1—H1C | 0.9600 | C7—H7A | 0.9300 |
| C1—H1D | 0.9600 | C8—C9 | 1.445 (3) |
| C1—H1E | 0.9600 | C9—C9i | 1.332 (4) |
| C1—H1F | 0.9600 | C9—H9A | 0.9300 |
| C2—C7 | 1.376 (3) | ||
| C8—O1—C5 | 103.41 (16) | C7—C2—C1 | 121.1 (2) |
| C8—N1—C6 | 103.80 (18) | C3—C2—C1 | 119.3 (2) |
| C2—C1—H1A | 109.5 | C4—C3—C2 | 123.1 (2) |
| C2—C1—H1B | 109.5 | C4—C3—H3A | 118.5 |
| H1A—C1—H1B | 109.5 | C2—C3—H3A | 118.5 |
| C2—C1—H1C | 109.5 | C5—C4—C3 | 115.3 (2) |
| H1A—C1—H1C | 109.5 | C5—C4—H4A | 122.3 |
| H1B—C1—H1C | 109.5 | C3—C4—H4A | 122.3 |
| C2—C1—H1D | 109.5 | C4—C5—C6 | 124.0 (2) |
| H1A—C1—H1D | 141.1 | C4—C5—O1 | 128.2 (2) |
| H1B—C1—H1D | 56.3 | C6—C5—O1 | 107.82 (17) |
| H1C—C1—H1D | 56.3 | C5—C6—N1 | 109.12 (18) |
| C2—C1—H1E | 109.5 | C5—C6—C7 | 119.39 (19) |
| H1A—C1—H1E | 56.3 | N1—C6—C7 | 131.5 (2) |
| H1B—C1—H1E | 141.1 | C2—C7—C6 | 118.5 (2) |
| H1C—C1—H1E | 56.3 | C2—C7—H7A | 120.7 |
| H1D—C1—H1E | 109.5 | C6—C7—H7A | 120.7 |
| C2—C1—H1F | 109.5 | N1—C8—O1 | 115.84 (19) |
| H1A—C1—H1F | 56.3 | N1—C8—C9 | 126.5 (2) |
| H1B—C1—H1F | 56.3 | O1—C8—C9 | 117.67 (19) |
| H1C—C1—H1F | 141.1 | C9i—C9—C8 | 123.6 (3) |
| H1D—C1—H1F | 109.5 | C9i—C9—H9A | 118.2 |
| H1E—C1—H1F | 109.5 | C8—C9—H9A | 118.2 |
| C7—C2—C3 | 119.6 (2) | ||
| C7—C2—C3—C4 | 0.6 (4) | C8—N1—C6—C7 | 179.4 (2) |
| C1—C2—C3—C4 | −178.7 (2) | C3—C2—C7—C6 | −1.2 (3) |
| C2—C3—C4—C5 | 0.0 (3) | C1—C2—C7—C6 | 178.1 (2) |
| C3—C4—C5—C6 | 0.0 (3) | C5—C6—C7—C2 | 1.2 (3) |
| C3—C4—C5—O1 | 179.20 (19) | N1—C6—C7—C2 | −177.7 (2) |
| C8—O1—C5—C4 | −178.4 (2) | C6—N1—C8—O1 | 0.2 (2) |
| C8—O1—C5—C6 | 0.9 (2) | C6—N1—C8—C9 | −179.5 (2) |
| C4—C5—C6—N1 | 178.5 (2) | C5—O1—C8—N1 | −0.7 (2) |
| O1—C5—C6—N1 | −0.9 (2) | C5—O1—C8—C9 | 178.99 (17) |
| C4—C5—C6—C7 | −0.7 (3) | N1—C8—C9—C9i | −179.1 (3) |
| O1—C5—C6—C7 | −179.99 (17) | O1—C8—C9—C9i | 1.2 (4) |
| C8—N1—C6—C5 | 0.4 (2) |
| Symmetry codes: (i) −x, −y+1, −z+2. |
The authors thank the Natural Science Foundation of Shandong Province (grant No. Y2005B04).
Drew, M. G. B. & Leslie, P. G. (1986). Acta Cryst. C42, 174–177.
Enraf–Nonius (1989). CAD-4 Software. Version 5.0. Enraf–Nonius, Delft, The Netherlands.
Huseyin, U., Van der Poorten, K., Cacciaguerra, S. & Spampinato, S. (1998). J. Med. Chem. 41, 1138–1145.
Koyama, E., Yang, G. & Kazuhisa, H. (2000). Tetrahedron Lett. 41, 8111–81116.
Sheldrick, G. M. (1990). SHELXTL/PC User's Manual. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.
Sheldrick, G. M. (1997). SHELXL97 and SHELXS97. University of Göttingen, Germany.
Benzoxazoles are compounds having a high fluorescence and are used as optical whitening agents, photoluminescents, and active components in dye lasers (Koyama et al., 2000). Benzoxazole derivatives show antiepileptic, antispasmodic and antifungal properties (Huseyin et al., 1998).
In the title compund, the bond lengths and angles in the two oxazole rings and two benzene rings are normal (Drew et al., 1986). C9—C9A bond distance of 1.332 (4)Å shows double bond character. The whole molecular is nearly planar. There is a π-π stacking interaction between the phenyl ring and oxazole ring at x,y + 1,z. The centroid-centroid distance between the six- and five-membered ring is 3.870Å and the perpendicular distance is 3.454 Å. In addition, there is a C—H···π interaction [C1—H1F···cg(C2,C3,C4,C5,C6,C7)i; symmetry operator (i) x,y − 1,z] with a H···cg distance of 3.516 Å.