A redetermination of 2-nitro­benzoic acid

Gustavo Portalone

doi:10.1107/S1600536809011830

. 2009 Apr 2;65(Pt 5):o954. doi: 10.1107/S1600536809011830

A redetermination of 2-nitrobenzoic acid

Gustavo Portalone ^a,^*

PMCID: PMC2977654 PMID: 21583997

Abstract

The crystal structure of the title compound, C₇H₅NO₄, was first reported by Kurahashi, Fukuyo & Shimada [(1967). Bull. Chem. Soc. Jpn, 40, 1296]. It has been re-examined, improving the precision of the derived geometric parameters. The asymmetric unit comprises a non-planar independent molecule, as the nitro and the carboxy substituents force each other to be twisted away from the plane of the aromatic ring by 54.9 (2) and 24.0 (2)°, respectively. The molecules form a conventional dimeric unit via centrosymmetric intermolecular hydrogen bonds.

Related literature

For the previous structure determination, see: Kurahashi et al. (1967 ▶); Sakore et al. (1967 ▶); Tavale & Pant (1973 ▶). For the effect of nitro and carboxy substitution on the geometry of polysubstituted benzene rings, see: Colapietro et al. (1984 ▶); Domenicano et al. (1989 ▶). For the formation of hydrogen-bonded dimers in monocarboylic acids, see:Leiserowitz (1976 ▶). For computation of ring patterns formed by hydrogen bonds in crystal structures, see: Etter et al. (1990 ▶); Bernstein et al. (1995 ▶); Motherwell et al. (1999 ▶).

Experimental

Crystal data

C₇H₅NO₄
M _r = 167.12
Triclinic,
a = 5.0147 (15) Å
b = 7.527 (2) Å
c = 10.620 (2) Å
α = 69.41 (2)°
β = 86.07 (2)°
γ = 71.01 (3)°
V = 354.35 (18) Å³
Z = 2
Mo Kα radiation
μ = 0.13 mm⁻¹
T = 298 K
0.15 × 0.15 × 0.10 mm

Data collection

Oxford Diffraction Xcalibur S CCD diffractometer
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2006 ▶) T _min = 0.879, T _max = 0.980
3862 measured reflections
1872 independent reflections
1087 reflections with I > 2σ(I)
R _int = 0.050

Refinement

R[F ² > 2σ(F ²)] = 0.077
wR(F ²) = 0.148
S = 1.07
1872 reflections
113 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.26 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2006 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2006 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809011830/kp2213sup1.cif

e-65-0o954-sup1.cif^{(14KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809011830/kp2213Isup2.hkl

e-65-0o954-Isup2.hkl^{(90.2KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2⋯O1ⁱ	0.90 (3)	1.77 (4)	2.660 (3)	173 (3)

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Symmetry code: (i) Inline graphic .

Acknowledgments

I thank MIUR (Rome) for 2006 financial support of the project ‘X-ray diffractometry and spectrometry’.

supplementary crystallographic information

Comment

o-Nitrobenzoic acid was determined more than 40 years ago (Kurahashi et al., 1967), but the final refinement was carried only to R=0.18. Subsequently, a new X-ray structure determination was reported (Sakore et al., 1967). In this study, 1250 unique reflections were collected at ambient temperature on an equi-inclination Weissenberg camera using Cu Kα radiation. Data were corrected for Lp effects as well as for the effect of spot extension, but not for absorption [µ(Cu Kα)= 135 mm^-1]. 694 visually estimated reflections having values significantly above background were used in the isotropic least-squares refinement. The final calculations led to R = 0.142 for 49 refined parameters, as the H atoms were not localized. A further anisotropic refinement of the structure was eventually carried out (Tavale & Pant, 1973). In this calculation, based on the same data set but with the inclusion of H atoms. the R factor decreased to 0.104, with a data-to-parameter ratio of 5.6, and average standard deviations of 0.013Å in C—C bond lengths and 0.9° in bond angles.

The asymmetric unit of (I) comprises a non-planar independent molecule, as the nitro and carboxy substituents force each other to be twisted away from the plane of the aromatic ring by 54.9 (2) and 24.0 (2)°, respectively (Fig. 1). The pattern of bond lengths and bond angles is consistent with those reported in previous structural investigations concerning the effect of the nitro and the carboxy groups on the geometry of polysubstituted benzene rings (Colapietro et al., 1984; Domenicano et al., 1989). Analysis of the crystal packing of (I), (Fig. 2), shows that the molecular components form the conventional dimeric units observed in monocarboylic acids (Leiserowitz, 1976). The structure is stabilized by very short [2.660 (3) Å] intermolecular O—H···O interactions of descriptor R²₂(8) (Etter et al., 1990; Bernstein et al., 1995; Motherwell et al., 1999) (Table 1) between the OH moiety and the carbonyl O atom (O1ⁱ) [symmetry code: (i) -x + 2, -y + 1, -z + 1].

Experimental

o-Nitrobenzoic acid (0.1 mmol, Sigma Aldrich at 95% purity) was dissolved in water (5 ml) and gently heated under reflux for 1 h. After cooling the solution to an ambient temperature, crystals suitable for single-crystal X-ray diffraction were grown by slow evaporation of the solvent after few days.