Acta Cryst. (2007). E63, o3709 [ doi:10.1107/S1600536807037178 ]
The conformation of the N-H bond in the title compound, C8H7Cl2NO, is syn to the ortho-chloro group and anti to the meta-chloro group, in contrast to the syn conformation observed with respect to both ortho- and meta-chloro substituents in N-(2,3-dichlorophenyl)acetamide and the anti conformation with respect to the meta-chloro substituent in N-(3,4-dichlorophenyl)acetamide. The dihedral angle between the dichlorophenyl and acetamide groups is 44.6 (2)°. Short Cl
Cl type II contacts (ClCl = 3.5 Å) and intermolecular N-HO hydrogen bonds link the molecules into chains.
The title compound was prepared according to the literature method of Shilpa and Gowda (Shilpa & Gowda, 2007). The purity of the compound was checked by determining its melting point. It was characterized by recording its infrared, NMR (Shilpa & Gowda, 2007) and NQR spectra (Pies et al., 1971). Single crystals of the title compound were obtained from a slow evaporation of its ethanolic solution (2 g in about 30 ml e thanol) and used for X-ray diffraction studies at room temperature.
All H atoms attached to C atoms were fixed geometrically and treated as riding with C–H = 0.93 Å (CH aromatic) or 0.96 Å (CH3) and Uiso(H) = 1.5 Ueq(CH3). N—H distance was restrained to 0.86 (1) Å.
Data collection: CAD-4-PC (Enraf–Nonius, 1996); cell refinement: CAD-4-PC; data reduction: REDU4 (Stoe & Cie, 1987); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97.
![[Figure 1]](./gw2016fig1thm.gif)
| Fig. 1. Molecular structure of the title compound showing the atom labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are represented as small spheres of arbitrary radii. |
![[Figure 2]](./gw2016fig2thm.gif)
| Fig. 2. Crystal packing of the title compound. Hydrogen bonds are shown as dashed lines. |
| C8H7Cl2NO | F000 = 416 |
| Mr = 204.05 | Dx = 1.517 Mg m−3 |
| Monoclinic, P21/n | Cu Kα radiation λ = 1.54180 Å |
| Hall symbol: -P 2yn | Cell parameters from 25 reflections |
| a = 5.8557 (4) Å | θ = 5.6–25.3º |
| b = 4.7942 (4) Å | µ = 6.13 mm−1 |
| c = 31.822 (2) Å | T = 299 (2) K |
| β = 90.531 (6)º | Prism, white |
| V = 893.31 (11) Å3 | 0.15 × 0.10 × 0.03 mm |
| Z = 4 |
| Enraf–Nonius CAD-4 diffractometer | Rint = 0.213 |
| Radiation source: fine-focus sealed tube | θmax = 66.9º |
| Monochromator: graphite | θmin = 2.8º |
| T = 299(2) K | h = −6→6 |
| ω/2θ scans | k = −5→1 |
| Absorption correction: ψ scan (North et al., 1968) | l = −37→37 |
| Tmin = 0.478, Tmax = 0.832 | 3 standard reflections |
| 3583 measured reflections | every 120 min |
| 1569 independent reflections | intensity decay: 1.0% |
| 1017 reflections with I > 2σ(I) |
| 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)] = 0.055 | H atoms treated by a mixture of independent and constrained refinement |
| wR(F2) = 0.108 | w = 1/[σ2(Fo2)] |
| S = 1.05 | (Δ/σ)max < 0.001 |
| 1569 reflections | Δρmax = 0.29 e Å−3 |
| 112 parameters | Δρmin = −0.48 e Å−3 |
| 1 restraint | Extinction correction: none |
| Primary atom site location: structure-invariant direct methods |
| C8H7Cl2NO | V = 893.31 (11) Å3 |
| Mr = 204.05 | Z = 4 |
| Monoclinic, P21/n | Cu Kα |
| a = 5.8557 (4) Å | µ = 6.13 mm−1 |
| b = 4.7942 (4) Å | T = 299 (2) K |
| c = 31.822 (2) Å | 0.15 × 0.10 × 0.03 mm |
| β = 90.531 (6)º |
| Enraf–Nonius CAD-4 diffractometer | 1017 reflections with I > 2σ(I) |
| Absorption correction: ψ scan (North et al., 1968) | Rint = 0.213 |
| Tmin = 0.478, Tmax = 0.832 | 3 standard reflections |
| 3583 measured reflections | every 120 min |
| 1569 independent reflections | intensity decay: 1.0% |
| R[F2 > 2σ(F2)] = 0.055 | 1 restraint |
| wR(F2) = 0.108 | H atoms treated by a mixture of independent and constrained refinement |
| S = 1.05 | Δρmax = 0.29 e Å−3 |
| 1569 reflections | Δρmin = −0.48 e Å−3 |
| 112 parameters |
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 | ||
| C1 | 0.2319 (10) | 0.7304 (5) | 0.01550 (14) | 0.058 (2) | |
| H1A | 0.1171 | 0.5979 | 0.0234 | 0.069* | |
| H1B | 0.3502 | 0.6368 | 0.0003 | 0.069* | |
| H1C | 0.1643 | 0.8718 | −0.0020 | 0.069* | |
| C2 | 0.3318 (8) | 0.8623 (5) | 0.05414 (13) | 0.0379 (12) | |
| C5 | 0.5242 (9) | 0.7740 (5) | 0.12195 (12) | 0.0357 (12) | |
| C6 | 0.7266 (8) | 0.6682 (5) | 0.13610 (12) | 0.0395 (12) | |
| C7 | 0.8178 (9) | 0.7474 (6) | 0.17467 (15) | 0.0468 (14) | |
| H7 | 0.9556 | 0.6719 | 0.1840 | 0.056* | |
| C8 | 0.7039 (9) | 0.9384 (6) | 0.19928 (14) | 0.0459 (14) | |
| H8 | 0.7638 | 0.9938 | 0.2251 | 0.055* | |
| C9 | 0.5013 (9) | 1.0442 (5) | 0.18487 (13) | 0.0396 (12) | |
| C10 | 0.4075 (9) | 0.9656 (5) | 0.14680 (13) | 0.0386 (12) | |
| H10 | 0.2685 | 1.0392 | 0.1378 | 0.046* | |
| N4 | 0.4305 (7) | 0.6906 (4) | 0.08251 (10) | 0.0371 (10) | |
| H4N | 0.424 (7) | 0.522 (3) | 0.0752 (12) | 0.045* | |
| O3 | 0.3239 (7) | 1.1152 (3) | 0.05928 (9) | 0.0610 (13) | |
| Cl11 | 0.8771 (2) | 0.43003 (17) | 0.10588 (4) | 0.0553 (4) | |
| Cl12 | 0.3522 (2) | 1.28471 (15) | 0.21550 (3) | 0.0535 (4) |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| C1 | 0.090 (5) | 0.0300 (13) | 0.053 (3) | 0.0036 (19) | −0.022 (3) | −0.0087 (15) |
| C2 | 0.043 (4) | 0.0297 (12) | 0.041 (3) | −0.0012 (17) | −0.001 (2) | 0.0017 (15) |
| C5 | 0.038 (3) | 0.0292 (12) | 0.040 (3) | −0.0044 (15) | −0.007 (2) | 0.0057 (14) |
| C6 | 0.036 (3) | 0.0314 (13) | 0.052 (3) | 0.0000 (17) | 0.001 (2) | 0.0075 (15) |
| C7 | 0.041 (4) | 0.0488 (16) | 0.051 (3) | 0.002 (2) | −0.007 (3) | 0.0082 (18) |
| C8 | 0.045 (4) | 0.0496 (17) | 0.043 (3) | −0.004 (2) | −0.011 (2) | 0.0026 (18) |
| C9 | 0.048 (4) | 0.0286 (13) | 0.043 (3) | −0.0049 (17) | 0.000 (2) | 0.0020 (14) |
| C10 | 0.042 (3) | 0.0298 (12) | 0.044 (3) | 0.0028 (17) | −0.001 (2) | 0.0013 (15) |
| N4 | 0.043 (3) | 0.0235 (10) | 0.045 (2) | 0.0026 (14) | −0.0064 (18) | −0.0024 (11) |
| O3 | 0.108 (4) | 0.0222 (8) | 0.052 (2) | 0.0035 (14) | −0.015 (2) | −0.0009 (11) |
| Cl11 | 0.0448 (10) | 0.0533 (5) | 0.0679 (9) | 0.0153 (5) | 0.0043 (6) | −0.0026 (5) |
| Cl12 | 0.0659 (12) | 0.0473 (4) | 0.0474 (8) | 0.0051 (5) | 0.0033 (6) | −0.0066 (4) |
| C1—C2 | 1.497 (4) | C6—Cl11 | 1.738 (5) |
| C1—H1A | 0.9600 | C7—C8 | 1.381 (7) |
| C1—H1B | 0.9600 | C7—H7 | 0.9300 |
| C1—H1C | 0.9600 | C8—C9 | 1.366 (6) |
| C2—O3 | 1.225 (3) | C8—H8 | 0.9300 |
| C2—N4 | 1.348 (4) | C9—C10 | 1.378 (5) |
| C5—C6 | 1.362 (5) | C9—Cl12 | 1.748 (5) |
| C5—C10 | 1.395 (6) | C10—H10 | 0.9300 |
| C5—N4 | 1.423 (4) | N4—H4N | 0.841 (10) |
| C6—C7 | 1.387 (5) | ||
| C2—C1—H1A | 109.5 | C8—C7—C6 | 120.0 (4) |
| C2—C1—H1B | 109.5 | C8—C7—H7 | 120.0 |
| H1A—C1—H1B | 109.5 | C6—C7—H7 | 120.0 |
| C2—C1—H1C | 109.5 | C9—C8—C7 | 118.6 (3) |
| H1A—C1—H1C | 109.5 | C9—C8—H8 | 120.7 |
| H1B—C1—H1C | 109.5 | C7—C8—H8 | 120.7 |
| O3—C2—N4 | 122.1 (3) | C8—C9—C10 | 122.1 (4) |
| O3—C2—C1 | 120.9 (3) | C8—C9—Cl12 | 119.6 (3) |
| N4—C2—C1 | 117.0 (2) | C10—C9—Cl12 | 118.3 (4) |
| C6—C5—C10 | 119.1 (3) | C9—C10—C5 | 119.0 (4) |
| C6—C5—N4 | 121.0 (4) | C9—C10—H10 | 120.5 |
| C10—C5—N4 | 119.9 (4) | C5—C10—H10 | 120.5 |
| C5—C6—C7 | 121.2 (4) | C2—N4—C5 | 125.3 (2) |
| C5—C6—Cl11 | 120.4 (3) | C2—N4—H4N | 113 (2) |
| C7—C6—Cl11 | 118.4 (3) | C5—N4—H4N | 122 (2) |
| C10—C5—C6—C7 | 0.1 (6) | C8—C9—C10—C5 | −0.7 (7) |
| N4—C5—C6—C7 | −179.5 (4) | Cl12—C9—C10—C5 | 180.0 (3) |
| C10—C5—C6—Cl11 | −179.8 (3) | C6—C5—C10—C9 | 0.5 (6) |
| N4—C5—C6—Cl11 | 0.6 (6) | N4—C5—C10—C9 | −179.9 (4) |
| C5—C6—C7—C8 | −0.5 (7) | O3—C2—N4—C5 | 3.6 (8) |
| Cl11—C6—C7—C8 | 179.3 (3) | C1—C2—N4—C5 | −176.7 (5) |
| C6—C7—C8—C9 | 0.4 (7) | C6—C5—N4—C2 | −137.7 (5) |
| C7—C8—C9—C10 | 0.2 (7) | C10—C5—N4—C2 | 42.7 (7) |
| C7—C8—C9—Cl12 | 179.6 (3) |
| D—H···A | D—H | H···A | D···A | D—H···A |
| N4—H4N···O3i | 0.841 (10) | 2.099 (14) | 2.921 (3) | 166 (4) |
| Symmetry codes: (i) x, y−1, z. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| N4—H4N···O3i | 0.841 (10) | 2.099 (14) | 2.921 (3) | 166 (4) |
| Symmetry codes: (i) x, y−1, z. |
BTG thanks the Alexander von Humboldt Foundation, Bonn, Germany, for extensions of his research fellowship.
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The amide moiety is an important constituent of many biologically significant compounds. The structural studies of amides are therefore of interest (Gowda et al., 2007a,b; Gowda, Kozisek et al., 2007, and references therein; Jones et al., 1990; Wan et al., 2006). As part of a study of the effect of ring and side chain substitutions on the solid state structures of this class of compounds (Gowda et al., 2007a,b; Gowda, Kozisek et al., 2007, and references therein), the crystal structure of N-(2,5-dichlorophenyl)-acetamide (25DCPA) has been determined. The conformation of the N—H bond in 25DCPA is syn to the ortho chloro group and anti to the meta chloro group (Fig. 1), in contrast to the syn conformation observed with respect to both ortho and meta chloro substituents in N-(2,3-dichlorophenyl)-acetamide (Gowda et al., 2007b) and anti conformation observed with respect to the meta chloro substituent in N-(3,4-dichlorophenyl)-acetamide (Jones et al., 1990). The bond lengths and angles in 25DCPA show normal values (Allen et al., 1987). The molecular skeleton is essentially planar. The dihedral angle between the mean planes of the dichlorophenyl and the acetamide moiety is 44.6 (2) °. The intermolecular N—H···O hydrogen bonds (Table 1) link the molecules into chains (Fig. 2). Further, a short ClA···Cl Type II contact (distance = 3.5 Å) controls the packing in the structure.