organic compounds
2-Amino-5-nitrobenzoic acid
aDepartment of Textile Engineering, Faculty of Engineering, Pamukkale University, TR-20070 Kınıklı Denizli, Turkey, bDepartment of Physics, Faculty of Arts & Science, Ondokuz Mayıs University, TR-55139 Kurupelit Samsun, Turkey, and cDepartment of Chemical Technonolgy, Pamukkale University, TR-20070 Kınıklı Denizli, Turkey
*Correspondence e-mail: orhanb@omu.edu.tr
In the title compound, C7H6N2O4, an intramolecular N—H⋯O hydrogen bond generates an S(6) ring. In the crystal, inversion dimers linked by pairs of O—H⋯O hydrogen bonds generate R22(8) loops. Intermolecular N—H⋯O and C—H⋯O hydrogen bonds then link the dimers, generating R33(16)R21(6) motifs. The whole molecule is essentially planar, with the greatest deviation from the mean plane being 0.065 (2) Å.
Related literature
For related structures of carboxylic acides, see: Mrozek & Glowiak (2004); Raza et al. (2010); Grabowski & Krygowski (1985). For hydrogen-bond motifs, see: Bernstein et al. (1995). For general background to o-aminocarboxylic acids, see: Fierz et al. (1949); Shore (2002).
Experimental
Crystal data
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Refinement
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Data collection: X-AREA (Stoe & Cie, 2002); cell X-AREA; data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
Supporting information
10.1107/S1600536812002474/fk2050sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536812002474/fk2050Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536812002474/fk2050Isup3.cml
Yellow needles of 2-amino-5-nitrobenzoic acid were obtained by slow evaporation of the analytical reagent (Alfa Aesar) from ethyl alcohol solution (m.p. 543 K).
The H(O) position was derived from Fourier maps (HFIX 147), other H atoms were positioned geometrically and all were constrained to ride on their parent atoms, with 0.86 Å for N—H, 0.93 Å for aromatic C-H and 0.82 Å for O-H. The Uiso(H) = xUeq(C/N), where x = 1.2 for H(N,C) and x = 1.5 for H(O).
Data collection: X-AREA (Stoe & Cie, 2002); cell
X-AREA (Stoe & Cie, 2002); data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).C7H6N2O4 | F(000) = 376 |
Mr = 182.14 | Dx = 1.601 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 4323 reflections |
a = 3.7026 (3) Å | θ = 1.7–28.0° |
b = 17.4638 (16) Å | µ = 0.13 mm−1 |
c = 11.6953 (10) Å | T = 296 K |
β = 92.210 (7)° | Needle, orange |
V = 755.67 (11) Å3 | 0.55 × 0.23 × 0.06 mm |
Z = 4 |
Stoe IPDS II diffractometer | 1567 independent reflections |
Radiation source: fine-focus sealed tube | 884 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.077 |
Detector resolution: 6.67 pixels mm-1 | θmax = 26.5°, θmin = 2.1° |
rotation method scans | h = −4→4 |
Absorption correction: integration (X-RED32; Stoe & Cie, 2002) | k = −21→21 |
Tmin = 0.964, Tmax = 0.992 | l = −13→14 |
5176 measured reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.064 | Hydrogen site location: geom and difmap |
wR(F2) = 0.127 | H-atom parameters constrained |
S = 0.99 | w = 1/[σ2(Fo2) + (0.0486P)2] where P = (Fo2 + 2Fc2)/3 |
1567 reflections | (Δ/σ)max < 0.001 |
118 parameters | Δρmax = 0.18 e Å−3 |
0 restraints | Δρmin = −0.15 e Å−3 |
C7H6N2O4 | V = 755.67 (11) Å3 |
Mr = 182.14 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 3.7026 (3) Å | µ = 0.13 mm−1 |
b = 17.4638 (16) Å | T = 296 K |
c = 11.6953 (10) Å | 0.55 × 0.23 × 0.06 mm |
β = 92.210 (7)° |
Stoe IPDS II diffractometer | 1567 independent reflections |
Absorption correction: integration (X-RED32; Stoe & Cie, 2002) | 884 reflections with I > 2σ(I) |
Tmin = 0.964, Tmax = 0.992 | Rint = 0.077 |
5176 measured reflections |
R[F2 > 2σ(F2)] = 0.064 | 0 restraints |
wR(F2) = 0.127 | H-atom parameters constrained |
S = 0.99 | Δρmax = 0.18 e Å−3 |
1567 reflections | Δρmin = −0.15 e Å−3 |
118 parameters |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 | ||
C1 | 0.6059 (8) | 0.35123 (17) | 0.7289 (3) | 0.0393 (7) | |
C2 | 0.7771 (8) | 0.34418 (16) | 0.8394 (2) | 0.0346 (7) | |
C3 | 0.8661 (8) | 0.27231 (16) | 0.8809 (3) | 0.0370 (7) | |
H3 | 0.9810 | 0.2678 | 0.9527 | 0.044* | |
C4 | 0.7890 (8) | 0.20744 (16) | 0.8187 (3) | 0.0380 (7) | |
C5 | 0.6210 (9) | 0.21311 (18) | 0.7098 (3) | 0.0444 (8) | |
H5 | 0.5688 | 0.1692 | 0.6673 | 0.053* | |
C6 | 0.5351 (9) | 0.28294 (17) | 0.6667 (3) | 0.0431 (8) | |
H6 | 0.4261 | 0.2862 | 0.5939 | 0.052* | |
C7 | 0.8660 (8) | 0.41190 (17) | 0.9097 (2) | 0.0383 (7) | |
N1 | 0.5107 (8) | 0.41812 (15) | 0.6824 (2) | 0.0548 (8) | |
H8 | 0.4074 | 0.4196 | 0.6154 | 0.066* | |
H7 | 0.5526 | 0.4599 | 0.7195 | 0.066* | |
N2 | 0.8912 (8) | 0.13354 (14) | 0.8636 (2) | 0.0502 (7) | |
O1 | 0.7787 (6) | 0.47709 (12) | 0.88101 (17) | 0.0513 (6) | |
O2 | 1.0433 (6) | 0.39701 (12) | 1.00684 (18) | 0.0528 (7) | |
H2 | 1.0837 | 0.4371 | 1.0415 | 0.079* | |
O3 | 1.0514 (7) | 0.12980 (13) | 0.9571 (2) | 0.0681 (8) | |
O4 | 0.8171 (9) | 0.07683 (14) | 0.8068 (2) | 0.0845 (10) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0370 (18) | 0.0391 (17) | 0.0415 (17) | 0.0007 (14) | −0.0015 (13) | 0.0015 (13) |
C2 | 0.0378 (17) | 0.0336 (16) | 0.0325 (15) | −0.0016 (14) | −0.0002 (12) | −0.0043 (13) |
C3 | 0.0391 (18) | 0.0395 (16) | 0.0321 (16) | −0.0021 (14) | −0.0016 (13) | −0.0019 (12) |
C4 | 0.0395 (18) | 0.0330 (16) | 0.0416 (18) | −0.0020 (13) | 0.0014 (13) | −0.0032 (13) |
C5 | 0.048 (2) | 0.0421 (19) | 0.0429 (18) | −0.0067 (15) | −0.0033 (14) | −0.0124 (14) |
C6 | 0.0469 (19) | 0.047 (2) | 0.0346 (17) | −0.0021 (15) | −0.0062 (14) | −0.0048 (13) |
C7 | 0.0434 (19) | 0.0348 (18) | 0.0365 (16) | −0.0006 (14) | −0.0019 (14) | −0.0014 (13) |
N1 | 0.080 (2) | 0.0407 (15) | 0.0426 (15) | 0.0062 (15) | −0.0147 (14) | 0.0012 (12) |
N2 | 0.0641 (19) | 0.0336 (15) | 0.0525 (17) | −0.0013 (14) | −0.0031 (14) | −0.0037 (13) |
O1 | 0.0766 (17) | 0.0322 (12) | 0.0440 (12) | −0.0002 (11) | −0.0120 (11) | −0.0020 (10) |
O2 | 0.0786 (17) | 0.0343 (11) | 0.0440 (13) | −0.0030 (11) | −0.0187 (12) | −0.0061 (9) |
O3 | 0.101 (2) | 0.0436 (14) | 0.0573 (15) | 0.0040 (13) | −0.0228 (15) | 0.0032 (11) |
O4 | 0.134 (3) | 0.0334 (14) | 0.084 (2) | −0.0019 (15) | −0.0263 (18) | −0.0118 (13) |
C1—N1 | 1.330 (4) | C5—H5 | 0.9300 |
C1—C6 | 1.416 (4) | C6—H6 | 0.9300 |
C1—C2 | 1.423 (4) | C7—O1 | 1.227 (3) |
C2—C3 | 1.381 (4) | C7—O2 | 1.316 (3) |
C2—C7 | 1.470 (4) | N1—H8 | 0.8600 |
C3—C4 | 1.370 (4) | N1—H7 | 0.8600 |
C3—H3 | 0.9300 | N2—O4 | 1.218 (3) |
C4—C5 | 1.399 (4) | N2—O3 | 1.226 (3) |
C4—N2 | 1.439 (4) | O2—H2 | 0.8200 |
C5—C6 | 1.353 (4) | ||
N1—C1—C6 | 119.3 (3) | C4—C5—H5 | 120.2 |
N1—C1—C2 | 123.3 (3) | C5—C6—C1 | 122.1 (3) |
C6—C1—C2 | 117.4 (3) | C5—C6—H6 | 118.9 |
C3—C2—C1 | 119.3 (3) | C1—C6—H6 | 118.9 |
C3—C2—C7 | 119.3 (3) | O1—C7—O2 | 122.5 (3) |
C1—C2—C7 | 121.4 (3) | O1—C7—C2 | 122.9 (3) |
C4—C3—C2 | 121.5 (3) | O2—C7—C2 | 114.7 (3) |
C4—C3—H3 | 119.2 | C1—N1—H8 | 120.0 |
C2—C3—H3 | 119.2 | C1—N1—H7 | 120.0 |
C3—C4—C5 | 120.1 (3) | H8—N1—H7 | 120.0 |
C3—C4—N2 | 120.1 (3) | O4—N2—O3 | 122.3 (3) |
C5—C4—N2 | 119.8 (3) | O4—N2—C4 | 118.7 (3) |
C6—C5—C4 | 119.5 (3) | O3—N2—C4 | 119.0 (3) |
C6—C5—H5 | 120.2 | C7—O2—H2 | 109.5 |
N1—C1—C2—C3 | 179.9 (3) | N1—C1—C6—C5 | −179.1 (3) |
C6—C1—C2—C3 | 0.1 (4) | C2—C1—C6—C5 | 0.8 (4) |
N1—C1—C2—C7 | −1.0 (4) | C3—C2—C7—O1 | −176.2 (3) |
C6—C1—C2—C7 | 179.1 (3) | C1—C2—C7—O1 | 4.8 (5) |
C1—C2—C3—C4 | −0.9 (4) | C3—C2—C7—O2 | 3.1 (4) |
C7—C2—C3—C4 | 180.0 (3) | C1—C2—C7—O2 | −176.0 (3) |
C2—C3—C4—C5 | 1.0 (5) | C3—C4—N2—O4 | 179.5 (3) |
C2—C3—C4—N2 | 178.9 (3) | C5—C4—N2—O4 | −2.5 (5) |
C3—C4—C5—C6 | −0.1 (5) | C3—C4—N2—O3 | −0.9 (5) |
N2—C4—C5—C6 | −178.1 (3) | C5—C4—N2—O3 | 177.0 (3) |
C4—C5—C6—C1 | −0.7 (5) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H7···O1 | 0.86 | 2.06 | 2.694 (3) | 130 |
N1—H7···O4i | 0.86 | 2.47 | 3.030 (3) | 123 |
N1—H8···O3ii | 0.86 | 2.39 | 3.192 (4) | 155 |
O2—H2···O1iii | 0.82 | 1.81 | 2.631 (3) | 174 |
C6—H6···O3ii | 0.93 | 2.54 | 3.347 (4) | 145 (3) |
Symmetry codes: (i) −x+1, y+1/2, −z+3/2; (ii) x−1, −y+1/2, z−1/2; (iii) −x+2, −y+1, −z+2. |
Experimental details
Crystal data | |
Chemical formula | C7H6N2O4 |
Mr | 182.14 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 296 |
a, b, c (Å) | 3.7026 (3), 17.4638 (16), 11.6953 (10) |
β (°) | 92.210 (7) |
V (Å3) | 755.67 (11) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.13 |
Crystal size (mm) | 0.55 × 0.23 × 0.06 |
Data collection | |
Diffractometer | Stoe IPDS II diffractometer |
Absorption correction | Integration (X-RED32; Stoe & Cie, 2002) |
Tmin, Tmax | 0.964, 0.992 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5176, 1567, 884 |
Rint | 0.077 |
(sin θ/λ)max (Å−1) | 0.628 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.064, 0.127, 0.99 |
No. of reflections | 1567 |
No. of parameters | 118 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.18, −0.15 |
Computer programs: X-AREA (Stoe & Cie, 2002), X-RED32 (Stoe & Cie, 2002), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H7···O1 | 0.86 | 2.06 | 2.694 (3) | 130.2 |
N1—H7···O4i | 0.86 | 2.47 | 3.030 (3) | 123.4 |
N1—H8···O3ii | 0.86 | 2.39 | 3.192 (4) | 155.2 |
O2—H2···O1iii | 0.82 | 1.81 | 2.631 (3) | 174.1 |
C6—H6···O3ii | 0.93 | 2.54 | 3.347 (4) | 145 (3) |
Symmetry codes: (i) −x+1, y+1/2, −z+3/2; (ii) x−1, −y+1/2, z−1/2; (iii) −x+2, −y+1, −z+2. |
Acknowledgements
The authors acknowledge the Faculty of Arts and Sciences, Ondokuz Mayıs University, Turkey, for the use of the Stoe IPDS II diffractometer (purchased under grant F.279 of the University Research Fund).
References
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Most dyes contain groups known as auxochromes (colour helpers), examples of which are carboxylic acid, sulfonic acid, amino, and hydroxyl groups. While these groups are not responsible for colour, their presence can shift the colour of a colourant and they are most often used to influence dye solubility. Aminocarboxylic acids dissolve as easily in carbonate solution as does benzoic acid, and as easily in aqueous hydrochloric acid as does aniline. o-Aminocarboxylic acids are used for synthesis of azo dyes and indigo dyes (Fierz et al., 1949; Shore, 2002). Functional groups such as carboxylic acids are completely inert in the reaction conditions for the azo coupling reaction. Taking into account these important features of the o-aminocarboxylic acids for the dye synthesis, we have undertaken the X-ray diffraction study of the 2-amino-5-nitrobenzoic acid, (I) (Fig. 1), in order to understand the molecular features which stabilize its observed conformation.
In previous works, 5-amino-2-nitrobenzoic acid (Mrozek & Glowiak, 2004), 2-Methylamino-5-nitrobenzoic acid (Raza et al., 2010), 2,5-dinitrobenzoic acid (Grabowski & Krygowski, 1985) have been published whose molecular structures are similar to the title compound.
(I) is essentially planar, the largest deviation from the mean plane being -0.065 (2) Å for atom O1. The crystal packing is stabilized by N-H···O, O-H···O and C-H···O hydrogen bonds. There exists an S(6) ring motif (Bernstein et al., 1995) due to the N-H···O intramolecular bond. Molecules are connected by intermolecular O-H···O hydrogen bonds to form centrosymmetric dimers with R22(8) ring motifs. Other hydrogen bonds generate R33(16)R21(6) motifs (Fig. 2 and Table 1).