4-Hydr­oxy-3-nitro­benzaldehyde

Mohd Razali Rizal; Isha Azizul; Seik Weng Ng

doi:10.1107/S1600536808011148

. 2008 Apr 26;64(Pt 5):o915. doi: 10.1107/S1600536808011148

4-Hydroxy-3-nitrobenzaldehyde

Mohd Razali Rizal ^a, Isha Azizul ^a, Seik Weng Ng ^a,^*

PMCID: PMC2961275 PMID: 21202397

Abstract

The hydroxyl group in each of the two independent molecules of the title compound, C₇H₅NO₄, participates in two O—H⋯O hydrogen bonds, viz. one intramolecular bond to the nitro group and one intermolecular bond to the aldehyde group of the same molecule in the next unit, resulting in a linear chain structure. The dihedral angle between the aromatic ring and the nitro group is 10.9 (3)° in one molecule and 9.9 (2)° in the other.

Related literature

For the structure of 2-nitrophenol, see: Iwasaki & Kawano (1978 ▶). For the structure of 4-hydroxybenzaldehyde, see: Jasinski et al. (2008 ▶).

Experimental

Crystal data

C₇H₅NO₄
M _r = 167.12
Triclinic,
a = 8.042 (1) Å
b = 8.036 (1) Å
c = 12.242 (2) Å
α = 71.975 (2)°
β = 70.820 (2)°
γ = 67.323 (2)°
V = 674.1 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.14 mm⁻¹
T = 100 (2) K
0.40 × 0.05 × 0.05 mm

Data collection

Bruker SMART APEX diffractometer
Absorption correction: none
4245 measured reflections
3068 independent reflections
2134 reflections with I > 2σ(I)
R _int = 0.016

Refinement

R[F ² > 2σ(F ²)] = 0.045
wR(F ²) = 0.121
S = 0.99
3068 reflections
225 parameters
2 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.31 e Å⁻³
Δρ_min = −0.32 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: X-SEED (Barbour, 2001 ▶); software used to prepare material for publication: publCIF (Westrip, 2008 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808011148/fl2191sup1.cif

e-64-0o915-sup1.cif^{(17KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808011148/fl2191Isup2.hkl

e-64-0o915-Isup2.hkl^{(150.5KB, 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
O4—H4o⋯O1ⁱ	0.84 (1)	2.13 (3)	2.676 (2)	122 (3)
O4—H4o⋯O3	0.84 (1)	1.91 (2)	2.638 (2)	144 (3)
O8—H8o⋯O5ⁱⁱ	0.84 (1)	2.10 (3)	2.687 (2)	128 (3)
O8—H8o⋯O7	0.84 (1)	1.94 (2)	2.635 (2)	139 (3)

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

We thank the University of Malaya for the purchase of the diffractometer.

supplementary crystallographic information

Comment

A nitro group either ortho or para to a hydroxyl group can significantly increase the acidity of the resulting phenol. The crystal structures of a large number of 2-nitrophenol compounds have reported; the title compound represents another example. The hydroxyl group of the two independent molecules of the title compound (Fig. 1) is intramolecularly linked to the nitro group by an O–H···O hydrogen bond; the hydroxy group is intermolecularly linked to the aldehyde group of the molecule in the next unit cell by an similar hydrogen bond to result in a linear chain structure (Fig. 2). 2-Nitrophenol itself features an intramolecular hydrogen bond of 2.602 Å (Iwasaki & Kawano, 1978). On the other hand, 4-hydroxybenzaldehyde exists as a hydrogen-bonded chain [O–H···O 2.731 (2) Å] (Jasinski et al., 2008).

Experimental

The commercially available compound (Sigma Aldrich) was recrystallized from water.