Acta Cryst. (2009). E65, o2340 [ doi:10.1107/S1600536809035247 ]
The title compound, C20H10F2N2O2, was synthesized from hydroquinone and 3,4-difluorobenzonitrile. The centroid of the central aromatic ring is on a crystallographic center of inversion. The dihedral angle between the central and terminal rings is 77.8 (3)°. In the crystal, chains linked by C-H
N bond occur.
A DMF (10 ml) solution of hydroquinone (1 mmol) and 3,4-difluorobenzonitrile (2 mmol) was heated to 70°C in the presence of KOH and stirred for 37 h. Then the mixture was washed with water (30 ml) and extracted with ethyl acetate (three times). The organic solvent was removed under reduced pressure. Afterwards the product was purified by column chromatography on silica (pentane - ethyl acetate mixtures). Single crystals were obtained by slow evaporation of the solvent of an ethanolic solution at room temperature.
H atoms were placed in calculated positions with C—H=0.93 Å. All H atoms were included in the final cycles of refinement using a riding model, with Uiso(H)=1.2Ueq of the carrier atoms.
Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2000); data reduction: SHELXTL (Sheldrick, 2008); 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]](./im2138fig1thm.gif)
| Fig. 1. Molecular structure of title compound with the atomic labeling scheme. Displacement ellipsoids are drawn at the 50% probability level. |
![[Figure 2]](./im2138fig2thm.gif)
| Fig. 2. A partial packing diagram of title compound. Hydrogen bonds are shown as dashed lines. [Symmetry code: (i) -x, -y, -z + 2]. |
| C20H10F2N2O2 | Z = 1 |
| Mr = 348.30 | F(000) = 178 |
| Triclinic, P1 | Dx = 1.469 Mg m−3 |
| Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
| a = 6.980 (1) Å | Cell parameters from 1140 reflections |
| b = 7.615 (1) Å | θ = 5.2–54.9° |
| c = 8.294 (1) Å | µ = 0.11 mm−1 |
| α = 106.376 (3)° | T = 293 K |
| β = 93.698 (3)° | Prismatic, colorless |
| γ = 109.085 (3)° | 0.42 × 0.37 × 0.32 mm |
| V = 393.7 (1) Å3 |
| Bruker SMART CCD area-detector diffractometer | 1529 independent reflections |
| Radiation source: fine-focus sealed tube | 1259 reflections with I > 2σ(I) |
| graphite | Rint = 0.065 |
| φ and ω scans | θmax = 26.0°, θmin = 2.6° |
| Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −8→7 |
| Tmin = 0.782, Tmax = 1.000 | k = −9→8 |
| 2165 measured reflections | l = −10→10 |
| 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)] = 0.047 | H-atom parameters constrained |
| wR(F2) = 0.137 | w = 1/[σ2(Fo2) + (0.0836P)2] where P = (Fo2 + 2Fc2)/3 |
| S = 1.07 | (Δ/σ)max = 0.001 |
| 1529 reflections | Δρmax = 0.19 e Å−3 |
| 119 parameters | Δρmin = −0.21 e Å−3 |
| 0 restraints | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
| Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.027 (6) |
| C20H10F2N2O2 | γ = 109.085 (3)° |
| Mr = 348.30 | V = 393.7 (1) Å3 |
| Triclinic, P1 | Z = 1 |
| a = 6.980 (1) Å | Mo Kα radiation |
| b = 7.615 (1) Å | µ = 0.11 mm−1 |
| c = 8.294 (1) Å | T = 293 K |
| α = 106.376 (3)° | 0.42 × 0.37 × 0.32 mm |
| β = 93.698 (3)° |
| Bruker SMART CCD area-detector diffractometer | 1529 independent reflections |
| Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 1259 reflections with I > 2σ(I) |
| Tmin = 0.782, Tmax = 1.000 | Rint = 0.065 |
| 2165 measured reflections | θmax = 26.0° |
| R[F2 > 2σ(F2)] = 0.047 | H-atom parameters constrained |
| wR(F2) = 0.137 | Δρmax = 0.19 e Å−3 |
| S = 1.07 | Δρmin = −0.21 e Å−3 |
| 1529 reflections | Absolute structure: ? |
| 119 parameters | Flack parameter: ? |
| 0 restraints | Rogers parameter: ? |
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 | ||
| O1 | 0.31400 (15) | 0.41880 (17) | 0.64633 (14) | 0.0546 (4) | |
| N1 | 0.2645 (2) | 0.0341 (2) | 1.2835 (2) | 0.0706 (5) | |
| F1 | 0.21076 (16) | 0.59370 (13) | 0.94706 (13) | 0.0663 (4) | |
| C1 | 0.2380 (2) | 0.4219 (2) | 0.9251 (2) | 0.0463 (4) | |
| C2 | 0.2823 (2) | 0.3307 (2) | 0.77070 (18) | 0.0443 (4) | |
| C3 | 0.3137 (2) | 0.1573 (2) | 0.7484 (2) | 0.0520 (4) | |
| H3 | 0.3429 | 0.0941 | 0.6448 | 0.062* | |
| C4 | 0.3023 (2) | 0.0761 (2) | 0.8780 (2) | 0.0524 (4) | |
| H4 | 0.3229 | −0.0419 | 0.8619 | 0.063* | |
| C5 | 0.2601 (2) | 0.1714 (2) | 1.03224 (18) | 0.0460 (4) | |
| C6 | 0.2256 (2) | 0.3453 (2) | 1.05636 (19) | 0.0483 (4) | |
| H6 | 0.1949 | 0.4084 | 1.1592 | 0.058* | |
| C7 | 0.2590 (2) | 0.0934 (2) | 1.1718 (2) | 0.0535 (4) | |
| C8 | 0.1518 (2) | 0.4580 (2) | 0.57622 (16) | 0.0424 (4) | |
| C9 | −0.0514 (2) | 0.3477 (2) | 0.56761 (18) | 0.0478 (4) | |
| H9 | −0.0856 | 0.2450 | 0.6129 | 0.057* | |
| C10 | 0.2042 (2) | 0.6087 (2) | 0.50919 (18) | 0.0472 (4) | |
| H10 | 0.3420 | 0.6816 | 0.5152 | 0.057* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| O1 | 0.0475 (6) | 0.0766 (8) | 0.0542 (7) | 0.0254 (5) | 0.0116 (5) | 0.0384 (6) |
| N1 | 0.0775 (11) | 0.0788 (11) | 0.0601 (9) | 0.0206 (8) | 0.0085 (8) | 0.0390 (8) |
| F1 | 0.0825 (8) | 0.0573 (7) | 0.0671 (7) | 0.0349 (5) | 0.0118 (5) | 0.0209 (5) |
| C1 | 0.0428 (8) | 0.0463 (8) | 0.0503 (9) | 0.0176 (6) | 0.0023 (6) | 0.0158 (7) |
| C2 | 0.0385 (7) | 0.0561 (9) | 0.0407 (8) | 0.0150 (6) | 0.0028 (6) | 0.0222 (7) |
| C3 | 0.0585 (9) | 0.0626 (10) | 0.0412 (8) | 0.0290 (8) | 0.0095 (7) | 0.0172 (7) |
| C4 | 0.0578 (9) | 0.0548 (9) | 0.0510 (9) | 0.0258 (7) | 0.0070 (7) | 0.0206 (7) |
| C5 | 0.0397 (8) | 0.0560 (9) | 0.0429 (8) | 0.0144 (6) | 0.0018 (6) | 0.0211 (7) |
| C6 | 0.0451 (8) | 0.0586 (9) | 0.0389 (8) | 0.0177 (7) | 0.0049 (6) | 0.0141 (7) |
| C7 | 0.0481 (9) | 0.0621 (10) | 0.0496 (9) | 0.0149 (7) | 0.0036 (7) | 0.0238 (8) |
| C8 | 0.0453 (8) | 0.0489 (8) | 0.0338 (7) | 0.0167 (6) | 0.0029 (6) | 0.0160 (6) |
| C9 | 0.0496 (9) | 0.0461 (8) | 0.0472 (9) | 0.0093 (6) | 0.0032 (6) | 0.0247 (7) |
| C10 | 0.0401 (8) | 0.0512 (9) | 0.0454 (8) | 0.0058 (6) | 0.0033 (6) | 0.0217 (7) |
| O1—C2 | 1.3731 (16) | C4—H4 | 0.9300 |
| O1—C8 | 1.3943 (16) | C5—C6 | 1.385 (2) |
| N1—C7 | 1.143 (2) | C5—C7 | 1.442 (2) |
| F1—C1 | 1.3469 (17) | C6—H6 | 0.9300 |
| C1—C6 | 1.368 (2) | C8—C10 | 1.3678 (19) |
| C1—C2 | 1.381 (2) | C8—C9 | 1.377 (2) |
| C2—C3 | 1.372 (2) | C9—C10i | 1.385 (2) |
| C3—C4 | 1.378 (2) | C9—H9 | 0.9300 |
| C3—H3 | 0.9300 | C10—C9i | 1.385 (2) |
| C4—C5 | 1.384 (2) | C10—H10 | 0.9300 |
| C2—O1—C8 | 118.23 (11) | C6—C5—C7 | 119.29 (14) |
| F1—C1—C6 | 119.41 (14) | C1—C6—C5 | 118.30 (14) |
| F1—C1—C2 | 118.49 (13) | C1—C6—H6 | 120.8 |
| C6—C1—C2 | 122.08 (14) | C5—C6—H6 | 120.8 |
| C3—C2—O1 | 119.59 (13) | N1—C7—C5 | 177.94 (17) |
| C3—C2—C1 | 118.81 (13) | C10—C8—C9 | 120.96 (13) |
| O1—C2—C1 | 121.32 (13) | C10—C8—O1 | 116.41 (12) |
| C2—C3—C4 | 120.60 (14) | C9—C8—O1 | 122.58 (12) |
| C2—C3—H3 | 119.7 | C8—C9—C10i | 119.29 (13) |
| C4—C3—H3 | 119.7 | C8—C9—H9 | 120.4 |
| C3—C4—C5 | 119.53 (15) | C10i—C9—H9 | 120.4 |
| C3—C4—H4 | 120.2 | C8—C10—C9i | 119.75 (13) |
| C5—C4—H4 | 120.2 | C8—C10—H10 | 120.1 |
| C4—C5—C6 | 120.67 (13) | C9i—C10—H10 | 120.1 |
| C4—C5—C7 | 120.00 (15) | ||
| C8—O1—C2—C3 | 123.31 (15) | C2—C1—C6—C5 | 0.4 (2) |
| C8—O1—C2—C1 | −62.84 (18) | C4—C5—C6—C1 | −1.1 (2) |
| F1—C1—C2—C3 | 178.88 (13) | C7—C5—C6—C1 | 176.65 (13) |
| C6—C1—C2—C3 | 0.4 (2) | C4—C5—C7—N1 | 80 (5) |
| F1—C1—C2—O1 | 5.0 (2) | C6—C5—C7—N1 | −98 (5) |
| C6—C1—C2—O1 | −173.52 (13) | C2—O1—C8—C10 | 154.42 (13) |
| O1—C2—C3—C4 | 173.66 (13) | C2—O1—C8—C9 | −28.1 (2) |
| C1—C2—C3—C4 | −0.3 (2) | C10—C8—C9—C10i | −0.4 (2) |
| C2—C3—C4—C5 | −0.4 (2) | O1—C8—C9—C10i | −177.78 (13) |
| C3—C4—C5—C6 | 1.2 (2) | C9—C8—C10—C9i | 0.4 (2) |
| C3—C4—C5—C7 | −176.60 (14) | O1—C8—C10—C9i | 177.93 (12) |
| F1—C1—C6—C5 | −178.13 (13) |
| Symmetry codes: (i) −x, −y+1, −z+1. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| C9—H9···N1ii | 0.93 | 2.50 | 3.410 (2) | 166 |
| Symmetry codes: (ii) −x, −y, −z+2. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| C9—H9···N1i | 0.93 | 2.50 | 3.410 (2) | 166 |
| Symmetry codes: (i) −x, −y, −z+2. |
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There has been growing interest in the study of hydroquinone derivatives which are important intermediates in the synthesis of herbicides (Liu, 2002. Bao et al., 2007). Only a few compounds of this kind have been structurally characterized so far. As part of our studies, we have synthesized the title compound from hydroquinone and 3,4-difluorobenzonitrile and report it's crystal structure in this article.
The crystal structure of the title compound (Fig. 1) utilizes the symmetry of the crystallographic inversion center similarily to a related selenium compound (Sørensen et al., 2009). The two terminal (C1—C7) phenyl ring and the central ring together with the attached oxygen (C8—C10/O1) form three planes. Due to crystallograhic symmetry the two terminal phenyl rings are coplanar. The terminal (C1—C7) phenyl ring plane and the central ring plane enclose a dihedral angle of 77.8 (3)°. Otherwise, the molecule is bent with the C2—O1—C8 angle of 118.25°.
In the crystal structure, intermolecular C—H···N hydrogen bonds (Tab.1) connect neighboring molecules with each other to form a one-dimensional chain that stretches along the c axis (Fig.2).