Cystal structre of 5-hy­droxy-2-nitro­benzaldehyde

In the title compound, C₇H₅NO₄, the nitro group and the aldehyde group are inclined to the benzene ring by 16.6 (3) and 15.6 (3)°, respectively. In the crystal, mol­ecules are linked via O—H...O hydrogen bonds, forming chains along [100]. The chains are linked by C—H...O hydrogen bonds, forming a three-dimensional structure.

Key indicators

• Single-crystal X-ray study
• T = 273 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.046
• wR factor = 0.116
• Data-to-parameter ratio = 11.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT127_ALERT_1_C Implicit Hall Symbol  Inconsistent with Explicit     P 2ybc
PLAT906_ALERT_3_C Large K value in the Analysis of Variance ......      6.104 Check

Alert level G
PLAT005_ALERT_5_G No _iucr_refine_instructions_details  in the CIF     Please Do !
PLAT066_ALERT_1_G Predicted and Reported Tmin&Tmax Range Identical          ? Check
PLAT199_ALERT_1_G Reported _cell_measurement_temperature ..... (K)        273 Check
PLAT200_ALERT_1_G Reported   _diffrn_ambient_temperature ..... (K)        273 Check
PLAT899_ALERT_4_G SHELXL97   is Deprecated and Succeeded by SHELXL       2014 Note

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   2 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   5 ALERT level G = General information/check it is not something unexpected

   4 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Synthesis and crystallization

Colourless crystals of the title compound [Fluka; HPLC grade] were obtained by slow evaporation of a solution in methanol.

S2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. The hydroxyl H atom was located in a difference Fourier map and freely refined. The C-bound H atoms were positioned geometrically and constrained to ride on their parent atoms: C—H = 0.93 Å, with U_iso(H) = 1.2U_eq(C).

S3. Comment

Nitro substituted aromatic compounds are well known inter­mediates in various organic reactions, responsible for synthesis of pesticides, explosive materials and other bioactive phenyl derivatives (Yan et al., 2006). The nitro substituted aromatic compounds are also known to be widely distributed as pollutant in air and water reservoirs (Yan et al., 2006; Soojhawon et al., 2005). The title compound is a commercially available benzaldehyde derivative, composed of a planar hy­droxy substituted nitro­benzaldehyde ring. The compound was crystal out as a part of our ongoing research project involving to crystallize and evaluate biological activities of commercially available molecular libraries.

The molecular structure of the title compound is illustrated in Fig. 1. Structurally it is a positional isomer of the previously reported 2-hy­droxy-5-nitro­benzaldehyde with the difference that the positions of the hy­droxy and nitro substituents are inter­changed (Tanak et al., 2009). The nitro group (N1/O1/O2) and the aldehyde group (C6/C1/O4) are inclined to the benzene ring (C1—C6) by 16.6 (3) and 15.6 (3) °, respectively.

In the crystal, molecules are linked by O—H···O hydrogen bonds forming zigzag chains along [100]. The chains are linked via C—H···O hydrogen bonds forming a three dimensional structure (Table 2 and Fig. 2).

Related literature

For literature on nitro-substituted aromatic compounds and their various properties, see: Yan et al. (2006); Soojhawon et al. (2005). For crystal structures of related compounds, see: Tang et al. (2010); Tanak et al. (2009); Singh et al. (2009).

Structure description

Nitro substituted aromatic compounds are well known inter­mediates in various organic reactions, responsible for synthesis of pesticides, explosive materials and other bioactive phenyl derivatives (Yan et al., 2006). The nitro substituted aromatic compounds are also known to be widely distributed as pollutant in air and water reservoirs (Yan et al., 2006; Soojhawon et al., 2005). The title compound is a commercially available benzaldehyde derivative, composed of a planar hy­droxy substituted nitro­benzaldehyde ring. The compound was crystal out as a part of our ongoing research project involving to crystallize and evaluate biological activities of commercially available molecular libraries.

The molecular structure of the title compound is illustrated in Fig. 1. Structurally it is a positional isomer of the previously reported 2-hy­droxy-5-nitro­benzaldehyde with the difference that the positions of the hy­droxy and nitro substituents are inter­changed (Tanak et al., 2009). The nitro group (N1/O1/O2) and the aldehyde group (C6/C1/O4) are inclined to the benzene ring (C1—C6) by 16.6 (3) and 15.6 (3) °, respectively.

In the crystal, molecules are linked by O—H···O hydrogen bonds forming zigzag chains along [100]. The chains are linked via C—H···O hydrogen bonds forming a three dimensional structure (Table 2 and Fig. 2).

For literature on nitro-substituted aromatic compounds and their various properties, see: Yan et al. (2006); Soojhawon et al. (2005). For crystal structures of related compounds, see: Tang et al. (2010); Tanak et al. (2009); Singh et al. (2009).

Synthesis and crystallization

Colourless crystals of the title compound [Fluka; HPLC grade] were obtained by slow evaporation of a solution in methanol.

Refinement details

Crystal data, data collection and structure refinement details are summarized in Table 2. The hydroxyl H atom was located in a difference Fourier map and freely refined. The C-bound H atoms were positioned geometrically and constrained to ride on their parent atoms: C—H = 0.93 Å, with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures

	Fig. 1. The molecular structure of title compound, with atom labelling. Displacement ellipsoids are drawn at 30% probability level.
	Fig. 2. The crystal packing of title compound, viewed along the b axis. Hydrogen bonds are shown as dashed lines (see Table 1 for details).

5-Hydroxy-2-nitrobenzaldehyde

Crystal data

C7H5NO4	F(000) = 344
Mr = 167.12	Dx = 1.574 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ybc	Cell parameters from 924 reflections
a = 9.6648 (18) Å	θ = 2.8–23.7°
b = 5.0917 (10) Å	µ = 0.13 mm^−1
c = 14.920 (3) Å	T = 273 K
β = 106.159 (4)°	Block, colourles
V = 705.2 (2) Å^3	0.48 × 0.32 × 0.15 mm
Z = 4

Data collection

Bruker SMART APEX CCD area-detector diffractometer	1312 independent reflections
Radiation source: fine-focus sealed tube	974 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.024
ω scan	θmax = 25.5°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −11→11
Tmin = 0.939, Tmax = 0.980	k = −5→6
3884 measured reflections	l = −18→16

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.116	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0518P)^2 + 0.1669P] where P = (Fo^2 + 2Fc^2)/3
1312 reflections	(Δ/σ)max < 0.001
113 parameters	Δρmax = 0.19 e Å^−3
0 restraints	Δρmin = −0.16 e Å^−3

Special details

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.

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

	x	y	z	Uiso*/Ueq
O1	0.0034 (2)	0.9749 (4)	−0.12613 (15)	0.0961 (7)
O2	0.1401 (2)	0.9319 (3)	−0.21588 (12)	0.0763 (6)
O3	0.42366 (18)	0.1329 (3)	0.09957 (10)	0.0571 (5)
O4	0.39446 (19)	0.3765 (4)	−0.22575 (10)	0.0671 (5)
N1	0.1039 (2)	0.8710 (4)	−0.14662 (14)	0.0577 (5)
C1	0.1847 (2)	0.6689 (4)	−0.08470 (13)	0.0440 (5)
C2	0.1690 (2)	0.6549 (4)	0.00439 (15)	0.0524 (6)
H2A	0.1050	0.7672	0.0218	0.063*
C3	0.2468 (2)	0.4774 (4)	0.06721 (14)	0.0504 (6)
H3A	0.2356	0.4691	0.1271	0.061*
C4	0.3419 (2)	0.3104 (4)	0.04173 (12)	0.0421 (5)
C5	0.3562 (2)	0.3232 (4)	−0.04816 (12)	0.0420 (5)
H5A	0.4192	0.2086	−0.0654	0.050*
C6	0.2793 (2)	0.5012 (4)	−0.11264 (12)	0.0408 (5)
C7	0.2988 (3)	0.4856 (4)	−0.20759 (14)	0.0543 (6)
H7A	0.2307	0.5677	−0.2560	0.065*
H3B	0.411 (3)	0.140 (5)	0.156 (2)	0.078 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0934 (14)	0.1045 (16)	0.0934 (14)	0.0513 (13)	0.0311 (12)	0.0152 (12)
O2	0.1128 (15)	0.0612 (11)	0.0566 (10)	0.0066 (10)	0.0265 (10)	0.0107 (8)
O3	0.0801 (11)	0.0627 (10)	0.0343 (8)	0.0137 (8)	0.0256 (8)	0.0081 (7)
O4	0.0813 (11)	0.0887 (13)	0.0398 (8)	0.0127 (10)	0.0307 (8)	−0.0016 (8)
N1	0.0660 (13)	0.0515 (12)	0.0528 (11)	0.0033 (10)	0.0117 (10)	−0.0038 (9)
C1	0.0457 (11)	0.0436 (11)	0.0427 (11)	−0.0009 (9)	0.0123 (9)	−0.0025 (9)
C2	0.0578 (13)	0.0528 (13)	0.0542 (13)	0.0027 (11)	0.0280 (11)	−0.0087 (10)
C3	0.0650 (14)	0.0565 (13)	0.0377 (11)	−0.0020 (11)	0.0273 (11)	−0.0030 (10)
C4	0.0518 (12)	0.0423 (11)	0.0354 (10)	−0.0046 (9)	0.0175 (9)	−0.0022 (9)
C5	0.0479 (11)	0.0477 (12)	0.0342 (10)	−0.0005 (9)	0.0177 (9)	−0.0063 (9)
C6	0.0439 (11)	0.0466 (11)	0.0333 (10)	−0.0081 (9)	0.0129 (9)	−0.0064 (8)
C7	0.0685 (15)	0.0608 (14)	0.0337 (11)	0.0090 (12)	0.0144 (11)	0.0026 (10)

Geometric parameters (Å, º)

O1—N1	1.218 (2)	C2—H2A	0.9300
O2—N1	1.219 (3)	C3—C4	1.381 (3)
O3—C4	1.344 (2)	C3—H3A	0.9300
O3—H3B	0.88 (3)	C4—C5	1.387 (3)
O4—C7	1.173 (2)	C5—C6	1.379 (3)
N1—C1	1.457 (3)	C5—H5A	0.9300
C1—C2	1.381 (3)	C6—C7	1.482 (3)
C1—C6	1.397 (3)	C7—H7A	0.9300
C2—C3	1.367 (3)
C4—O3—H3B	111.7 (17)	O3—C4—C3	123.70 (17)
O1—N1—O2	122.6 (2)	O3—C4—C5	116.94 (18)
O1—N1—C1	118.2 (2)	C3—C4—C5	119.36 (18)
O2—N1—C1	119.2 (2)	C6—C5—C4	121.73 (18)
C2—C1—C6	120.82 (19)	C6—C5—H5A	119.1
C2—C1—N1	117.63 (19)	C4—C5—H5A	119.1
C6—C1—N1	121.50 (18)	C5—C6—C1	117.64 (17)
C3—C2—C1	120.47 (19)	C5—C6—C7	116.39 (18)
C3—C2—H2A	119.8	C1—C6—C7	125.87 (19)
C1—C2—H2A	119.8	O4—C7—C6	124.3 (2)
C2—C3—C4	119.97 (18)	O4—C7—H7A	117.8
C2—C3—H3A	120.0	C6—C7—H7A	117.8
C4—C3—H3A	120.0
O1—N1—C1—C2	−16.9 (3)	C3—C4—C5—C6	1.0 (3)
O2—N1—C1—C2	162.27 (19)	C4—C5—C6—C1	−0.5 (3)
O1—N1—C1—C6	165.7 (2)	C4—C5—C6—C7	−176.99 (18)
O2—N1—C1—C6	−15.2 (3)	C2—C1—C6—C5	−0.2 (3)
C6—C1—C2—C3	0.4 (3)	N1—C1—C6—C5	177.18 (18)
N1—C1—C2—C3	−177.03 (19)	C2—C1—C6—C7	175.9 (2)
C1—C2—C3—C4	0.0 (3)	N1—C1—C6—C7	−6.7 (3)
C2—C3—C4—O3	179.1 (2)	C5—C6—C7—O4	−17.1 (3)
C2—C3—C4—C5	−0.7 (3)	C1—C6—C7—O4	166.8 (2)
O3—C4—C5—C6	−178.86 (18)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3B···O4^i	0.88 (3)	1.82 (3)	2.699 (2)	174 (3)
C2—H2A···O1^ii	0.93	2.48	3.364 (3)	158
C5—H5A···O3^iii	0.93	2.45	3.379 (3)	173
C7—H7A···O1^iv	0.93	2.49	3.264 (3)	140

Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) −x, −y+2, −z; (iii) −x+1, −y, −z; (iv) −x, y−1/2, −z−1/2.