(E)-2-[(4-Fluoro­phen­yl)imino­meth­yl]-5-methoxy­phenol

Çiğdem Albayrak; Arzu Özek; Başak Koşar; Mustafa Odabaşoğlu; Orhan Büyükgüngör

doi:10.1107/S1600536810000474

. 2010 Jan 9;66(Pt 2):o315. doi: 10.1107/S1600536810000474

(E)-2-[(4-Fluorophenyl)iminomethyl]-5-methoxyphenol

Çiğdem Albayrak ^a,^*, Arzu Özek ^b, Başak Koşar ^a, Mustafa Odabaşoğlu ^c, Orhan Büyükgüngör ^b

PMCID: PMC2979905 PMID: 21579745

Abstract

In the molecule of the title compound, C₁₄H₁₂FNO₂, the aromatic rings are oriented at a dihedral angle of 48.17 (1)°. An intramolecular O—H⋯N hydrogen bond results in the formation of a six-membered ring. The title molecule is a phenol–imine tautomer, as evidenced by the C—O [1.351 (3) Å], C—N [1.282 (3) Å], and C—C [1.416 (3)–1.445 (3) Å] bond lengths. In the crystal, molecules are linked by intermolecular C—H⋯π interactions.

Related literature

The present work is part of a structural study of Schiff bases, see: Özek et al. (2007 ▶); Odabaşoğlu et al. (2007 ▶); Albayrak et al. (2005 ▶). For related structures, see: Özek et al. (2007 ▶, 2009 ▶).

Experimental

Crystal data

C₁₄H₁₂FNO₂
M _r = 245.25
Monoclinic,
a = 13.1806 (7) Å
b = 7.1785 (5) Å
c = 6.4297 (3) Å
β = 97.967 (4)°
V = 602.49 (6) Å³
Z = 2
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 296 K
0.68 × 0.48 × 0.17 mm

Data collection

Stoe IPDS II diffractometer
Absorption correction: integration (X-RED32; Stoe & Cie, 2002 ▶) T _min = 0.932, T _max = 0.985
6287 measured reflections
1399 independent reflections
1273 reflections with I > 2σ(I)
R _int = 0.037

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.104
S = 1.09
1399 reflections
168 parameters
3 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.11 e Å⁻³

Data collection: X-AREA (Stoe & Cie, 2002 ▶); cell refinement: 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 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810000474/bt5163sup1.cif

e-66-0o315-sup1.cif^{(17KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810000474/bt5163Isup2.hkl

e-66-0o315-Isup2.hkl^{(67.6KB, hkl)}

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

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

Cg1 and Cg2 are the centroids of C1—C6 and C9—C14 rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯N1	0.82 (2)	1.87 (2)	2.615 (3)	150 (3)
C6—H6⋯Cg1ⁱ	0.93	2.73	3.4363	133
C11—H11⋯Cg2ⁱⁱ	0.93	2.93	3.6414	134
C14—H14⋯Cg2ⁱⁱⁱ	0.93	2.91	3.6076	133

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

Acknowledgments

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).

supplementary crystallographic information

Comment

The present work is part of a structural study of Schiff bases (Özek et al., 2009; Özek et al., 2007) and we report here the structure of (E)-2-(4-Fluorophenylimino)methyl-5-methoxyphenol, (I).

The ortho-hydroxy Schiff Bases that show tautomerism by the intramolecular proton transfer from an oxygen atom to the neighboring nitrogen atom are important compounds. These compounds can exist in three different structures as enol, keto or zwitterionic forms in the solid state. The title compound (I) consists of two aromatic rings (C1 to C6 and C9 to C14), and an imino frame (C9—N1—C8—C1). In (E)-2-(4-Fluorophenylimino)methyl- 5-methoxyphenol which adopts an E configuration about the C=N double bond, dihedral angle between the aromatic rings is 48.17 (1) °. The H atom in title compound (I) is located on atom O1, thus the phenol-imine tautomer is favored over the keto-amine form, as indicated by the C2—O1, C8—N1, C1—C8 and C1—C2 bond lengths (Fig. 1 and Table 2). The O1—C2 bond length of 1.351 (2) Å indicates single-bond character, whereas the N1—C8 bond length of 1.283 (2) Å indicates double-bond character. A similar work was observed for X-ray crystal and computational structural study of (E)-2-[(4-bromophenyl)iminomethyl] -4-methoxyphenol [C—O=1.358 (4) Å, C—N= 1.287 (4) Å, Özek et al., 2007].

It is known that Schiff bases may exhibit thermochromism or photochromism, depending on the planarity or non-planarity of the molecule, respectively. Therefore, one can expect photochromic properties in (I) caused by non-planarity of the molecules; the dihedral angle between rings A(C1—C6) and B ring (C9—C14) is 48.17 (1) °. The intramolecular O—H···N hydrogen bond (Table 1) results in the formation of six-membered ring and it generates an S(6) ring motif. The O1···N1 distance of 2.614 (2) Å is comparable to those observed for analogous hydrogen bonds in "Three (E)-2-[(bromophenyl)iminomethyl]-4-methoxyphenols" [2.603 (2) Å, 2.638 (7) Å, 2.577 (4) Å; Özek et al., 2007]. In the crystal structure, C—H···π interactions exist (Table 1) (Fig. 2).

Experimental

The compound (E)-2-(4-Fluorophenylimino)methyl-5-methoxyphenol was prepared by reflux a mixture of a solution containing 4-methoxysalicylaldehyde (0.5 g 3.3 mmol) in 20 ml e thanol and a solution containing 4-fluoroaniline (0.37 g 3.3 mmol) in 20 ml e thanol. The reaction mixture was stirred for 1 h under reflux. The crystals of (E)-2-(4-Fluorophenylimino)methyl-5-methoxyphenol suitable for X-ray analysis were obtained from ethanol by slow evaporation (yield % 82; m.p. 368–369 K).