(E)-3-[(3-Eth­oxy-2-hy­droxy­benzyl­idene)amino]­benzoic acid

Hadi Kargar; Zahra Sharafi; Reza Kia; Muhammad Nawaz Tahir

doi:10.1107/S1600536812009968

. 2012 Mar 10;68(Pt 4):o1035. doi: 10.1107/S1600536812009968

(E)-3-[(3-Ethoxy-2-hydroxybenzylidene)amino]benzoic acid

Hadi Kargar ^a,^*, Zahra Sharafi ^b, Reza Kia ^c, Muhammad Nawaz Tahir ^d,^*

PMCID: PMC3343997 PMID: 22589906

Abstract

In the title compound, C₁₆H₁₅NO₄, a potential bidentate N,O-donor Schiff base ligand, the benzene rings are inclined to one another by 4.24 (12)°. The molecule has an E conformation about the C=N bond. An intramolecular O—H⋯N hydrogen bond makes an S(6) ring motif. In the crystal, pairs of O—H⋯O hydrogen bonds link the molecules, forming inversion dimers with R ₂ ²(8) ring motifs. These dimers are further connected by C—H⋯O interactions, forming a sheet in (104). There is also a C—H⋯π interaction present involving neighbouring molecules.

Related literature

For background to Schiff bases ligands and their metal complexes, see: Kargar et al. (2011 ▶, 2012 ▶); Kia et al. (2010 ▶). For standard bond lengths, see: Allen et al. (1987 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₁₆H₁₅NO₄
M _r = 285.29
Triclinic,
a = 5.0306 (3) Å
b = 7.1847 (4) Å
c = 19.6856 (13) Å
α = 94.956 (4)°
β = 93.310 (4)°
γ = 102.299 (4)°
V = 690.45 (7) Å³
Z = 2
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 296 K
0.22 × 0.12 × 0.08 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.979, T _max = 0.992
11954 measured reflections
3331 independent reflections
1429 reflections with I > 2σ(I)
R _int = 0.058

Refinement

R[F ² > 2σ(F ²)] = 0.061
wR(F ²) = 0.150
S = 0.95
3331 reflections
191 parameters
H-atom parameters constrained
Δρ_max = 0.15 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812009968/su2387sup1.cif

e-68-o1035-sup1.cif^{(17.9KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812009968/su2387Isup2.hkl

e-68-o1035-Isup2.hkl^{(163.4KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812009968/su2387Isup3.cml

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

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

Cg2 is the centroid of the C9–C14 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3A⋯N1	0.99	1.75	2.570 (3)	138
O1—H1A⋯O2ⁱ	0.99	1.63	2.610 (2)	174
C3—H3B⋯O1ⁱⁱ	0.93	2.58	3.453 (3)	157
C4—H4A⋯O2ⁱⁱⁱ	0.93	2.53	3.341 (3)	146
C15—H15A⋯Cg2^iv	0.97	2.75	3.610 (3)	148

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

Acknowledgments

HK thanks PNU for financial support. MNT thanks GC University of Sargodha, Pakistan, for the research facility.

supplementary crystallographic information

Comment

In continuation of our work on the crystal structure analysis of Schiff base ligands (Kargar et al., 2011, 2012; Kia et al., 2010), we synthesized and determined the crystal structure of the new title potential bidentate N,O-donor Schiff base.

The molecular structure of the title compound is illustrated in Fig. 1. The bond lengths (Allen et al., 1987) and angles are within the normal ranges. The intramolecular O3—H3A···N1 hydrogen bond (Table 1) makes an S(6) ring motif (Bernstein et al., 1995). The dihedral angle between the benzene rings is 4.24 (12)°. The molecule has an E conformation about the C8═N1 bond.

In the crystal, pairs of O—H···O hydrogen bonds (Table 1) link molecules to form inversion dimers with an R²₂(8) ring motif. These dimers are connected further by C—H···O interactions along the b axis direction, forming a sheet (Fig. 2). There is also a C-H···π interaction present involving neighbouring molecules (Table 1).

Experimental

The title compound was synthesized by adding 3-ethoxysalicylaldehyde (2 mmol) to a solution of 3-carboxyaniline (2 mmol) in ethanol (30 ml). The mixture was refluxed with stirring for 30 min. The resultant solution was filtered. Pale yellow single crystals of the title compound, suitable for X-ray structure determination, were obtained by recrystallization from ethanol, by slow evaporation of the solvents at room temperature over several days.