Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536801010704/tk6018sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536801010704/tk6018Isup2.hkl |
CCDC reference: 170886
Key indicators
- Single-crystal X-ray study
- T = 294 K
- Mean (C-C) = 0.002 Å
- R factor = 0.050
- wR factor = 0.168
- Data-to-parameter ratio = 15.5
checkCIF results
No syntax errors found ADDSYM reports no extra symmetry
The title compound was acquired from a commercial source (Aldrich). The crystal used for the data collection was obtained by slow evaporation from acetone–water (2:1) saturated solution at room temperature.
The C-bound H atoms were placed in their geometrically calculated positions and included in the final refinement in the riding-model approximation.
Data collection: SMART (Siemens, 1995); cell refinement: SMART; data reduction: SHELXTL-NT (Siemens, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL-NT; software used to prepare material for publication: SHELXTL-NT.
Fig. 1. The molecular structure of (I) with ellipsoids at the 30% probability level (Bruker, 1995). |
C8H7FN2O3 | ? # Insert any comments here. |
Mr = 198.16 | Dx = 1.531 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 3.9758 (7) Å | Cell parameters from 2891 reflections |
b = 22.489 (4) Å | θ = 1–27.5° |
c = 9.7419 (16) Å | µ = 0.13 mm−1 |
β = 99.255 (3)° | T = 294 K |
V = 859.7 (3) Å3 | Prism, colorless |
Z = 4 | 0.20 × 0.18 × 0.16 mm |
F(000) = 408 |
CCD area-detector diffractometer | 1984 independent reflections |
Radiation source: fine-focus sealed tube | 1284 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.024 |
ϕ and ω scans | θmax = 27.6°, θmin = 1.8° |
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996) | h = −3→5 |
Tmin = 0.974, Tmax = 0.979 | k = −28→29 |
5833 measured reflections | l = −12→12 |
Refinement on F2 | 0 restraints |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.050 | H-atom parameters constrained |
wR(F2) = 0.168 | w = 1/[σ2(Fo2) + (0.1P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.06 | (Δ/σ)max = 0.001 |
1978 reflections | Δρmax = 0.36 e Å−3 |
128 parameters | Δρmin = −0.27 e Å−3 |
C8H7FN2O3 | V = 859.7 (3) Å3 |
Mr = 198.16 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 3.9758 (7) Å | µ = 0.13 mm−1 |
b = 22.489 (4) Å | T = 294 K |
c = 9.7419 (16) Å | 0.20 × 0.18 × 0.16 mm |
β = 99.255 (3)° |
CCD area-detector diffractometer | 1984 independent reflections |
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996) | 1284 reflections with I > 2σ(I) |
Tmin = 0.974, Tmax = 0.979 | Rint = 0.024 |
5833 measured reflections |
R[F2 > 2σ(F2)] = 0.050 | 0 restraints |
wR(F2) = 0.168 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.36 e Å−3 |
1978 reflections | Δρmin = −0.27 e Å−3 |
128 parameters |
Experimental. ? #Insert any special details here. |
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 | ||
F1 | −0.1764 (4) | 0.48038 (5) | 0.13792 (14) | 0.0918 (4) | |
O1 | 0.3856 (5) | 0.56838 (6) | 0.57282 (13) | 0.0834 (5) | |
O2 | 0.5886 (3) | 0.65023 (5) | 0.50742 (12) | 0.0596 (3) | |
O3 | 0.1745 (4) | 0.74926 (5) | 0.10882 (11) | 0.0608 (4) | |
N1 | 0.3966 (4) | 0.60772 (6) | 0.48671 (13) | 0.0494 (3) | |
N2 | 0.1221 (4) | 0.71019 (5) | 0.31778 (12) | 0.0436 (3) | |
H2B | 0.1282 | 0.7179 | 0.4046 | 0.052* | |
C1 | 0.1738 (4) | 0.60185 (7) | 0.35285 (14) | 0.0422 (4) | |
C2 | 0.0921 (5) | 0.54448 (7) | 0.30961 (17) | 0.0530 (4) | |
H2A | 0.1695 | 0.5121 | 0.3653 | 0.064* | |
C3 | −0.1050 (5) | 0.53653 (8) | 0.18310 (19) | 0.0602 (5) | |
C4 | −0.2316 (5) | 0.58320 (8) | 0.10011 (19) | 0.0601 (5) | |
H4A | −0.3654 | 0.5765 | 0.0140 | 0.072* | |
C5 | −0.1565 (5) | 0.64031 (7) | 0.14688 (17) | 0.0497 (4) | |
H5A | −0.2490 | 0.6722 | 0.0929 | 0.060* | |
C6 | 0.0549 (4) | 0.65141 (7) | 0.27332 (14) | 0.0404 (4) | |
C7 | 0.1781 (4) | 0.75578 (7) | 0.23279 (14) | 0.0414 (4) | |
C8 | 0.2416 (5) | 0.81489 (7) | 0.30182 (17) | 0.0556 (5) | |
H8D | 0.2775 | 0.8442 | 0.2339 | 0.083* | |
H8A | 0.4400 | 0.8126 | 0.3722 | 0.083* | |
H8B | 0.0480 | 0.8260 | 0.3437 | 0.083* |
U11 | U22 | U33 | U12 | U13 | U23 | |
F1 | 0.1200 (10) | 0.0569 (7) | 0.0939 (9) | −0.0204 (7) | 0.0035 (7) | −0.0253 (6) |
O1 | 0.1242 (13) | 0.0670 (9) | 0.0540 (7) | 0.0045 (8) | −0.0011 (8) | 0.0191 (6) |
O2 | 0.0580 (8) | 0.0673 (7) | 0.0502 (7) | −0.0008 (6) | −0.0010 (6) | −0.0042 (6) |
O3 | 0.0953 (9) | 0.0570 (7) | 0.0325 (5) | −0.0032 (6) | 0.0180 (6) | 0.0046 (5) |
N1 | 0.0583 (8) | 0.0512 (7) | 0.0392 (6) | 0.0122 (7) | 0.0092 (6) | 0.0024 (6) |
N2 | 0.0619 (8) | 0.0423 (7) | 0.0268 (5) | −0.0009 (6) | 0.0073 (5) | 0.0000 (5) |
C1 | 0.0449 (8) | 0.0460 (8) | 0.0378 (7) | 0.0026 (7) | 0.0129 (6) | −0.0008 (6) |
C2 | 0.0621 (11) | 0.0452 (9) | 0.0533 (9) | 0.0027 (8) | 0.0138 (8) | 0.0005 (7) |
C3 | 0.0670 (12) | 0.0508 (10) | 0.0650 (10) | −0.0113 (9) | 0.0173 (9) | −0.0154 (8) |
C4 | 0.0602 (11) | 0.0706 (12) | 0.0476 (9) | −0.0083 (9) | 0.0022 (8) | −0.0129 (8) |
C5 | 0.0510 (9) | 0.0564 (10) | 0.0408 (8) | −0.0039 (8) | 0.0047 (7) | −0.0024 (7) |
C6 | 0.0442 (8) | 0.0455 (8) | 0.0336 (7) | −0.0004 (6) | 0.0122 (6) | −0.0013 (6) |
C7 | 0.0457 (8) | 0.0473 (8) | 0.0316 (7) | 0.0039 (7) | 0.0069 (6) | 0.0055 (6) |
C8 | 0.0732 (12) | 0.0500 (10) | 0.0446 (8) | −0.0072 (9) | 0.0123 (8) | 0.0018 (7) |
F1—C3 | 1.352 (2) | C2—H2A | 0.9300 |
O1—N1 | 1.2249 (18) | C3—C4 | 1.370 (3) |
O2—N1 | 1.2197 (18) | C4—C5 | 1.379 (2) |
O3—C7 | 1.2144 (17) | C4—H4A | 0.9300 |
N1—C1 | 1.4598 (19) | C5—C6 | 1.398 (2) |
N2—C7 | 1.3585 (18) | C5—H5A | 0.9300 |
N2—C6 | 1.4032 (19) | C7—C8 | 1.493 (2) |
N2—H2B | 0.8600 | C8—H8D | 0.9600 |
C1—C2 | 1.380 (2) | C8—H8A | 0.9600 |
C1—C6 | 1.396 (2) | C8—H8B | 0.9600 |
C2—C3 | 1.362 (2) | ||
O2—N1—O1 | 122.90 (14) | C5—C4—H4A | 120.7 |
O2—N1—C1 | 119.49 (13) | C4—C5—C6 | 121.66 (16) |
O1—N1—C1 | 117.59 (14) | C4—C5—H5A | 119.2 |
C7—N2—C6 | 124.37 (12) | C6—C5—H5A | 119.2 |
C7—N2—H2B | 117.8 | C1—C6—C5 | 116.66 (14) |
C6—N2—H2B | 117.8 | C1—C6—N2 | 123.38 (13) |
C2—C1—C6 | 122.35 (14) | C5—C6—N2 | 119.87 (13) |
C2—C1—N1 | 115.89 (14) | O3—C7—N2 | 122.56 (14) |
C6—C1—N1 | 121.76 (14) | O3—C7—C8 | 121.97 (14) |
C3—C2—C1 | 118.18 (15) | N2—C7—C8 | 115.46 (12) |
C3—C2—H2A | 120.9 | C7—C8—H8D | 109.5 |
C1—C2—H2A | 120.9 | C7—C8—H8A | 109.5 |
F1—C3—C4 | 119.04 (16) | H8D—C8—H8A | 109.5 |
F1—C3—C2 | 118.51 (16) | C7—C8—H8B | 109.5 |
C4—C3—C2 | 122.45 (16) | H8D—C8—H8B | 109.5 |
C3—C4—C5 | 118.62 (16) | H8A—C8—H8B | 109.5 |
C3—C4—H4A | 120.7 | ||
O2—N1—C1—C2 | 150.10 (15) | C2—C1—C6—C5 | 0.7 (2) |
O1—N1—C1—C2 | −28.4 (2) | N1—C1—C6—C5 | 179.94 (14) |
O2—N1—C1—C6 | −29.2 (2) | C2—C1—C6—N2 | 177.08 (15) |
O1—N1—C1—C6 | 152.28 (16) | N1—C1—C6—N2 | −3.7 (2) |
C6—C1—C2—C3 | 1.6 (3) | C4—C5—C6—C1 | −2.8 (3) |
N1—C1—C2—C3 | −177.67 (15) | C4—C5—C6—N2 | −179.35 (16) |
C1—C2—C3—F1 | 177.73 (16) | C7—N2—C6—C1 | 143.82 (16) |
C1—C2—C3—C4 | −1.9 (3) | C7—N2—C6—C5 | −39.9 (2) |
F1—C3—C4—C5 | −179.78 (18) | C6—N2—C7—O3 | 0.0 (3) |
C2—C3—C4—C5 | −0.1 (3) | C6—N2—C7—C8 | 179.46 (15) |
C3—C4—C5—C6 | 2.6 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2B···O3i | 0.86 | 2.10 | 2.9536 (16) | 170 |
Symmetry code: (i) x, −y+3/2, z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C8H7FN2O3 |
Mr | 198.16 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 294 |
a, b, c (Å) | 3.9758 (7), 22.489 (4), 9.7419 (16) |
β (°) | 99.255 (3) |
V (Å3) | 859.7 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.13 |
Crystal size (mm) | 0.20 × 0.18 × 0.16 |
Data collection | |
Diffractometer | CCD area-detector diffractometer |
Absorption correction | Empirical (using intensity measurements) (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.974, 0.979 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5833, 1984, 1284 |
Rint | 0.024 |
(sin θ/λ)max (Å−1) | 0.652 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.050, 0.168, 1.06 |
No. of reflections | 1978 |
No. of parameters | 128 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.36, −0.27 |
Computer programs: SMART (Siemens, 1995), SMART, SHELXTL-NT (Siemens, 1995), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), SHELXTL-NT.
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2B···O3i | 0.86 | 2.10 | 2.9536 (16) | 170 |
Symmetry code: (i) x, −y+3/2, z+1/2. |
One of the structural characteristics of 4'-fluoro-2'-nitroacetanilide, (I), is the presence of a pair of the electron-donating (–NH2) and electron-withdrawing (–NO2) groups, a feature which enhances the dipole moments of this molecule through both inductive and resonance effects (Fletton et al., 1986). In addition, molecule (I) contains a single fluoride substituent on its aromatic ring, the signal of which can be easily detected via 19F NMR methods. A molecule possessing such structural characteristics in crystalline form is deemed to be an ideal candidate for the examination of the hypothesis of time-reversal symmetry violation, a physics theory postulated in the recent years (Li & Nadin, 1995, 1998). As part of our efforts investigating this theory, we present the crystal structure of (I).
The amide group in (I) (Fig. 1) is rotated out of the ring plane, with a dihedral angle of 16.30 (6)°. Similarly, the nitro group is slightly twisted out of the aromatic ring plane by 29.60 (10)°. The amide N atom approaches the amide O atom of an adjacent molecule at a distance of 2.9536 (16) Å, indicating intermolecular hydrogen bonding. It is also noted that (I) crystallizes in a centrosymmetric space group.
According to the theory of time-reversal symmetry violation (Li & Nadin, 1995, 1998), the magnitudes of the two electric currents operating in opposite directions along the same aromatic ring of (I) will be different, thus resulting in two different signals for the chemical shifts of F atom in (I). Studies into this effect are underway.