2-Eth­oxy-6-({2-[(3-eth­oxy-2-hy­droxy­benzyl­idene)amino]­benz­yl}imino­meth­yl)phenol

K U Ambili; S S Sreejith; Jinsa Mary Jacob; M Sithambaresan; M R Prathapachandra Kurup

doi:10.1107/S1600536812031479

. 2012 Jul 18;68(Pt 8):o2482. doi: 10.1107/S1600536812031479

2-Ethoxy-6-({2-[(3-ethoxy-2-hydroxybenzylidene)amino]benzyl}iminomethyl)phenol

K U Ambili ^a, S S Sreejith ^a, Jinsa Mary Jacob ^a, M Sithambaresan ^b,^*, M R Prathapachandra Kurup ^a

PMCID: PMC3414937 PMID: 22904924

Abstract

The title compound, C₂₅H₂₆N₂O₄, exists in an E conformation with respect to each azomethine link. The two phenol-substituted benzene rings are twisted away from the plane of the diimine benzene ring by dihedral angles of 27.25 (5) and 56.67 (5)°. The molecular structure is stabilized by intramolecular O—H⋯N hydrogen bonds.

Related literature

For the applications of salen Schiff bases, see: Cozzi (2004 ▶); Hodnett & Dunn (1970 ▶). For the synthesis of Schiff bases, see: Tümer (2000 ▶). For a related structure, see: Aslantaş et al. (2007 ▶).

Experimental

Crystal data

C₂₅H₂₆N₂O₄
M _r = 418.48
Monoclinic,
a = 4.8315 (4) Å
b = 17.5414 (14) Å
c = 25.828 (2) Å
β = 94.356 (3)°
V = 2182.6 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 296 K
0.40 × 0.20 × 0.20 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.979, T _max = 0.983
32150 measured reflections
3833 independent reflections
2543 reflections with I > 2σ(I)
R _int = 0.044

Refinement

R[F ² > 2σ(F ²)] = 0.038
wR(F ²) = 0.112
S = 1.05
3833 reflections
291 parameters
2 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.13 e Å⁻³
Δρ_min = −0.13 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: APEX2 and SAINT (Bruker, 2004 ▶); data reduction: SAINT and XPREP (Bruker, 2004 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97 and publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812031479/fj2580sup1.cif

e-68-o2482-sup1.cif^{(28.8KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812031479/fj2580Isup2.hkl

e-68-o2482-Isup2.hkl^{(187.9KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812031479/fj2580Isup3.cml

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—H2O⋯N1	0.85 (1)	1.79 (1)	2.5711 (19)	151 (2)
O3—H3O⋯N2	0.85 (1)	1.80 (1)	2.5844 (19)	152 (2)

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Acknowledgments

The authors are grateful to the Sophisticated Analytical Instruments Facility, Cochin University of Science and Technology, Kochi-22, India, for providing the single-crystal X-ray diffraction data. MRPK, KUA and SSS thank the Defence Research Development Organization, New Delhi, India, for financial support. JMJ thanks the Council of Scientific and Industrial Research, New Delhi, India, for a Senior Research Fellowship.

supplementary crystallographic information

Comment

The chelating structure, moderate electron donation and easy tunable electronic and steric effects make dicompartmental salen type Schiff bases to act as versatile ligands. They are able to stabilize different metals in various oxidation states and control the performance of the metals in various catalytic transformations (Cozzi, 2004). Schiff bases are very selective in the sense that they provide geometrical cavity control for host guest interaction and modulate its lipophilicity to stabilize a specific metal ion. Moreover, it has been suggested that the azomethine linkage in Schiff bases is responsible for their biological activities such as antimicrobial, antifungal and antitumor and also to be used as herbicides (Hodnett & Dunn, 1970).

The E conformation of the compound is evidenced from the torsion angles, 176.94 (14)° and 179.38 (15)° made by the C10—N1—C9—C7 and C16—N2—C17—C18 linkages respectively. The bond lengths and bond angles are in normal ranges and agree with the related structure (Aslantaş, et al., 2007). The crystal involves two intramolecular O—H···N hydrogen bonds and C—H···π interactions which make the molecule stable.

Experimental

The title compound was prepared according to the reported procedure (Tümer, 2000) by the condensation of the ethanolic solution of 3-ethoxy-2-hydroxybenzaldehyde (1 mmol, 0.166 g) with an ethanolic solution of 2-aminobenzylamine (0.5 mmol, 0.061 g). The reaction mixture was heated to reflux for 6 h and kept for cooling at room temperature. The slow evaporation yielded orange-yellow crystals of N,N'-bis(3-ethoxy-2-hydroxybenzylidene)-2-aminobenzylamine.