4′ Fluoro 2′ nitro­acetanilide

Acta Cryst.(2001). E57, o675±o676 DOI: 10.1107/S1600536801010704 Qi, Zhou, Liu and Chan C₈H₇FN₂O₃

o675

organic papers

Acta Crystallographica Section E Structure Reports Online

ISSN 1600-5368

4

_-Fluoro-2

_{-nitroacetanilide}

Jianying Qi,* Zhongyuan Zhou, Dongsheng Liu and Albert S. C. Chan

Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong

Correspondence e-mail: [email protected]

Key indicators Single-crystal X-ray study

T= 294 K

Mean(C±C) = 0.002 AÊ

Rfactor = 0.050

wRfactor = 0.168

Data-to-parameter ratio = 15.5

For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.

#2001 International Union of Crystallography Printed in Great Britain ± all rights reserved

The crystal structure of the title compound, C8H7FN2O3,

shows that the amide and nitro groups are rotated slightly out of the aromatic plane, with dihedral angles of 16.30 (6) and 29.60 (10)_{, respectively. The overall molecular organization is}

stabilized by well de®ned intermolecular hydrogen bonds that lead to the formation of in®nite chains.

Comment

One of the structural characteristics of 40_-¯uoro-20

-nitro-acetanilide, (I), is the presence of a pair of electron-donating (±NH2) and electron-withdrawing (±NO2) groups, a feature

which enhances the dipole moment of this molecule through both inductive and resonance effects (Flettonet al., 1986). In addition, molecule (I) contains a single ¯uoro substituent on its aromatic ring, the signal of which can be easily detectedvia

19_{F NMR methods. A molecule possessing such structural}

characteristics in crystalline form is deemed to be an ideal candidate for 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 inves-tigating 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) AÊ, indi-cating intermolecular hydrogen bonding. It is also noted that (I) crystallizes in a centrosymmetric space group.

According to the theory of time-reversal symmetry viola-tion (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 the F atom in (I). Studies into this effect are underway.

Experimental

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.

Crystal data C8H7FN2O3

Mr= 198.16

Monoclinic,P21/c

a= 3.9758 (7) AÊ

b= 22.489 (4) AÊ

c= 9.7419 (16) AÊ

= 99.255 (3)

V= 859.7 (3) AÊ3

Z= 4

Dx= 1.531 Mg mÿ3

MoKradiation Cell parameters from 2891

re¯ections

= 1±27.5 = 0.13 mmÿ1

T= 294 (2) K Prism, colorless 0.200.180.16 mm Data collection

CCD area-detector diffractometer

'and!scans

Absorption correction: empirical (SADABS; Sheldrick, 1996)

Tmin= 0.974,Tmax= 0.979

5833 measured re¯ections 1984 independent re¯ections

1284 re¯ections withI> 2(I)

Rint= 0.024 max= 27.6

h=ÿ3!5

k=ÿ28!29

l=ÿ12!12

Re®nement Re®nement onF2

R[F2_{> 2(F}2_{)] = 0.050}

wR(F2_{) = 0.168}

S= 1.06 1978 re¯ections 128 parameters

H-atom parameters constrained

w= 1/[2_(F

o2) + (0.1P)2]

whereP= (Fo2+ 2Fc2)/3

(/)max= 0.001 max= 0.36 e AÊÿ3 min=ÿ0.27 e AÊÿ3

Table 1

Hydrogen-bonding geometry (AÊ,_).

DÐH A DÐH H A D A DÐH A

N2ÐH2B O3i _{0.86 2.10 2.9536 (16) 170}

Symmetry code: (i)x;3

2ÿy;12‡z.

The C-bound H atoms were placed in their geometrically calcu-lated positions and included in the ®nal re®nement in the riding-model approximation.

Data collection: SMART (Siemens, 1995); cell re®nement:

SMART; data reduction: SHELXTL-NT (Siemens, 1995);

program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to re®ne structure:SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL-NT; software used to prepare material for publication:SHELXTL-NT.

We thank Dr Tianhu Li for his helpful discussion on the topic of time-reversal symmetry violation.

References

Fletton, R. A., Lancaster, R. W., Harris, R. K., Kenwright, M., Packer, K. J., Waters, D. N. & Yeadon, A. (1986).J. Chem. Soc. Perkin Trans.2, pp. 1075± 1709.

Li, T. & Nadin, A. (1995).Phys.Lett. A,206, 222±224. Li, T. & Nadin, A. (1998).Chirality,10, 289±293. Sheldrick, G. M. (1990).Acta Cryst.A46, 467±473.

Sheldrick, G. M. (1996).SADABS. University of GoÈttingen, Germany. Sheldrick, G. M. (1997).SHELXL97. University of GoÈttingen, Germany. Siemens (1995).SMART(Version 5.0) andSHELXTL-NT(Version 5.10).

Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.

Figure 1

supporting information

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Acta Cryst. (2001). E57, o675–o676

supporting information

Acta Cryst. (2001). E57, o675–o676 [doi:10.1107/S1600536801010704]

4

′

-Fluoro-2

′

-nitroacetanilide

Jianying Qi, Zhongyuan Zhou, Dongsheng Liu and Albert S. C. Chan

S1. Comment

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 19_{F 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.

S2. Experimental

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.

S3. Refinement

The C-bound H atoms were placed in their geometrically calculated positions and included in the final refinement in the

Figure 1

The molecular structure of (I) with ellipsoids at the 30% probability level (Bruker, 1995).

4′-fluoro-2′-nitroacetanilide

Crystal data

C8H7FN2O3 Mr = 198.16 Monoclinic, P21/c a = 3.9758 (7) Å b = 22.489 (4) Å c = 9.7419 (16) Å β = 99.255 (3)° V = 859.7 (3) Å3 Z = 4

F(000) = 408

? # Insert any comments here. Dx = 1.531 Mg m−3

Mo Kα radiation, λ = 0.71073 Å Cell parameters from 2891 reflections θ = 1–27.5°

µ = 0.13 mm−1 T = 294 K Prism, colorless 0.20 × 0.18 × 0.16 mm

Data collection

CCD area-detector diffractometer

Radiation source: fine-focus sealed tube Graphite monochromator

φ and ω scans

Absorption correction: empirical (using intensity measurements)

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Acta Cryst. (2001). E57, o675–o676

Rint = 0.024

θmax = 27.6°, θmin = 1.8° h = −3→5

k = −28→29 l = −12→12

Refinement

Refinement on F2 Least-squares matrix: full R[F2 _{> 2σ(F}2_{)] = 0.050} wR(F2_{) = 0.168} S = 1.06 1978 reflections 128 parameters 0 restraints

Hydrogen site location: inferred from neighbouring sites

H-atom parameters constrained w = 1/[σ2_(Fo2_{) + (0.1P)}2_]

where P = (Fo2 _{+ 2Fc}2_)/3 (Δ/σ)max = 0.001

Δρmax = 0.36 e Å−3 Δρmin = −0.27 e Å−3

Special details

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 F}2_, conventional R-factors R are based on F, with F set to zero for negative F2_{. The threshold expression of F}2 _{> σ(F}2_{) 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2₎

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*

Atomic displacement parameters (Å2₎

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)

Geometric parameters (Å, º)

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

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Acta Cryst. (2001). E57, o675–o676

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)

Hydrogen-bond geometry (Å, º)

D—H···A D—H H···A D···A D—H···A

N2—H2B···O3i _{0.86 2.10 2.9536 (16) 170}