organic compounds
(E)-1-[(2-Fluorophenyl)iminomethyl]-2-naphthol–(Z)-1-[(2-fluorophenyl)aminomethylidene]naphthalen-2(1H)-one (0.57/0.43)
aDepartment of Physics, Faculty of Arts & Science, Ondokuz Mayıs University, TR-55139 Kurupelit-Samsun, Turkey, and bDepartment of Chemistry, Faculty of Arts & Science, Ondokuz Mayıs University, TR-55139 Kurupelit-Samsun, Turkey
*Correspondence e-mail: orhanb@omu.edu.tr
The title Schiff base compound, 0.57C17H12FNO·0.43C17H12FNO, reveals both the enol (OH) and keto (NH) tautomeric forms with occupancies of 0.57 (6) and 0.43 (6), respectively. The tautomeric forms are stabilized by intramolecular O—H⋯N (enol) and N—H⋯O (keto) hydrogen bonds. The dihedral angle between the naphthalene ring system and the benzene ring is 32.76 (1)°.
Related literature
For the biological properties of et al. (1975). For the coordination chemistry of see: Kargar et al. (2009); Yeap et al. (2009). For Schiff base see: Hökelek et al. (2000); Kaitner & Pavlovic (1996); Karabıyık et al. (2007); Nazır et al. (2000); Odabaşoğlu et al. (2005); Yıldız et al. (1998); Tanak et al. (2009). For bond-length data, see: Allen et al. (1987).
see: LozierExperimental
Crystal data
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Refinement
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Data collection: X-AREA (Stoe & Cie, 2002); cell 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).
Supporting information
https://doi.org/10.1107/S1600536810014777/ci5080sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810014777/ci5080Isup2.hkl
The title compound was prepared by refluxing a mixture of a solution containing 2-hydroxy-1-naphthaldehyde (172 mg, 1 mmol) in 50 ml ethanol and a solution containing 2-fluoroaniline (111 mg, 1 mmol) in 30 ml ethanol. The reaction mixture was stirred for 3 h under reflux. The crystals of the title compound were obtained by slow evaporation of ethanol (yield 68%; m.p. 361-363 K). The FT-IR spectra of the title compound was recorded on a KBr pellets with a Schmadzu FT-IR 8900 spectrophotometer. IR (KBr) ν = 3558 (O–H), 3420 (N–H), 1698 (C═O) weak, 1620 (C═N) cm-1.
The
could not be determined from X-ray data, as no strong anomalous scatterer is present; 1058 Friedel pairs were merged before the final All H atoms (except H1A and H1B) were placed in calculated positions and constrained to ride on their parent atoms, with C–H = 0.93 Å and Uiso(H) = 1.2 Ueq(C). Inspection of the tautomeric hydrogen atom's (H1) location in difference Fourier map between O1 and N1 indicated that there is a positional disorder for this H atom. Hence, atoms H1A and H1B bonded with O1 and N1 were positioned geometrically and their occupancies were refined to 0.57 (6) and 0.43 (6), respectively. A restraint (DELU instruction in SHELXL97, Sheldrick, 2008) was used in order to maintain a reasonable geometry and atomic displacement parameters for atoms C13 and F1.Schiff bases often exhibit various biological activities and in many cases were shown to have antibacterial, anticancer, anti-inflammatory and antitoxic properties (Lozier et al., 1975). ǧlu et al., 2005) tautomeric forms. In the solid state, while OH tautomeric forms of are predominant in salicylaldimines (Kaitner & Pavlovic, 1996; Yıldız et al.,1998), both NH and OH forms have been found in naphthaldimine Schiff base compounds (Nazır et al., 2000; Karabıyık et al., 2007). Our investigations shows that in the title compound both OH (enol) and NH (keto) tautomers coexist with occupancies of 0.57 (6) and 0.43 (6), respectively. This evidence is also supported by the observed IR vibrational bands given in the experimental section.
have also been used as versatile ligands in coordination chemistry (Kargar et al., 2009; Yeap et al., 2009). There are two types of intramolecular hydrogen bonds in namely N—H···O in keto (NH) (Hökelek et al., 2000) and N···H—O in enol (OH) (OdabaşoAn ORTEP-3 (Farrugia, 1997) plot of the molecule of (I) is shown in Fig.1. The C2—O1 [1.314 (5) Å] and C11—N1 [1.306 (4) Å] bond lengths are intermediate between the single and double C—O (1.362 and 1.222 Å, respectively) and C—N bond lengths (1.339 and 1.279 Å, respectively) (Allen et al., 1987). Similar results were observed for 2-[(2,4-dimethylphenyl)iminomethyl]-3,5-dimethoxyphenol (Tanak et al., 2009). The molecule of the title compound is not planar, with a dihedral angle of 32.76 (1)° between naphthalene and benzene rings. The molecular structure is stabilized by O—H···N or N—H···O hydrogen bonds.
For the biological properties of ǧlu et al. (2005); Yıldız et al. (1998); Tanak et al. (2009). For bond-length data, see: Allen et al. (1987).
see: Lozier et al. (1975). For the coordination chemistry of see: Kargar et al. (2009); Yeap et al. (2009). For Schiff base see: Hökelek et al. (2000); Kaitner & Pavlovic (1996); Karabıyık et al. (2007); Nazır et al. (2000); OdabaşoData collection: X-AREA (Stoe & Cie, 2002); cell
X-AREA (Stoe & Cie, 2002); 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).0.57C17H12FNO·0.43C17H12FNO | F(000) = 552 |
Mr = 265.28 | Dx = 1.359 Mg m−3 |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 4776 reflections |
a = 7.2841 (3) Å | θ = 1.4–27.8° |
b = 12.2158 (6) Å | µ = 0.10 mm−1 |
c = 14.5731 (7) Å | T = 296 K |
V = 1296.73 (10) Å3 | Needle, yellow |
Z = 4 | 0.73 × 0.31 × 0.10 mm |
Stoe IPDSII diffractometer | 1477 independent reflections |
Radiation source: fine-focus sealed tube | 951 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.040 |
Detector resolution: 6.67 pixels mm-1 | θmax = 26.0°, θmin = 2.2° |
ω scans | h = −8→8 |
Absorption correction: integration (X-RED32; Stoe & Cie, 2002) | k = −13→15 |
Tmin = 0.967, Tmax = 0.993 | l = −17→16 |
5655 measured reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.047 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.113 | H-atom parameters constrained |
S = 0.97 | w = 1/[σ2(Fo2) + (0.0576P)2] where P = (Fo2 + 2Fc2)/3 |
1477 reflections | (Δ/σ)max = 0.001 |
183 parameters | Δρmax = 0.23 e Å−3 |
1 restraint | Δρmin = −0.14 e Å−3 |
0.57C17H12FNO·0.43C17H12FNO | V = 1296.73 (10) Å3 |
Mr = 265.28 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 7.2841 (3) Å | µ = 0.10 mm−1 |
b = 12.2158 (6) Å | T = 296 K |
c = 14.5731 (7) Å | 0.73 × 0.31 × 0.10 mm |
Stoe IPDSII diffractometer | 1477 independent reflections |
Absorption correction: integration (X-RED32; Stoe & Cie, 2002) | 951 reflections with I > 2σ(I) |
Tmin = 0.967, Tmax = 0.993 | Rint = 0.040 |
5655 measured reflections |
R[F2 > 2σ(F2)] = 0.047 | 1 restraint |
wR(F2) = 0.113 | H-atom parameters constrained |
S = 0.97 | Δρmax = 0.23 e Å−3 |
1477 reflections | Δρmin = −0.14 e Å−3 |
183 parameters |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
C1 | 0.3705 (5) | 0.8439 (3) | 0.5517 (2) | 0.0525 (9) | |
C2 | 0.4237 (5) | 0.7941 (4) | 0.6359 (3) | 0.0643 (10) | |
C3 | 0.4381 (5) | 0.8594 (4) | 0.7158 (3) | 0.0736 (12) | |
H3 | 0.4738 | 0.8268 | 0.7707 | 0.088* | |
C4 | 0.4018 (5) | 0.9661 (4) | 0.7144 (3) | 0.0700 (11) | |
H4 | 0.4127 | 1.0060 | 0.7685 | 0.084* | |
C5 | 0.3467 (5) | 1.0212 (3) | 0.6328 (3) | 0.0614 (10) | |
C6 | 0.3091 (6) | 1.1331 (4) | 0.6324 (3) | 0.0780 (12) | |
H6 | 0.3201 | 1.1728 | 0.6866 | 0.094* | |
C7 | 0.2573 (8) | 1.1848 (4) | 0.5552 (4) | 0.0927 (14) | |
H7 | 0.2337 | 1.2596 | 0.5562 | 0.111* | |
C8 | 0.2390 (7) | 1.1264 (4) | 0.4742 (3) | 0.0899 (14) | |
H8 | 0.2024 | 1.1621 | 0.4209 | 0.108* | |
C9 | 0.2744 (6) | 1.0171 (3) | 0.4721 (3) | 0.0706 (11) | |
H9 | 0.2614 | 0.9793 | 0.4171 | 0.085* | |
C10 | 0.3302 (4) | 0.9598 (3) | 0.5510 (2) | 0.0520 (8) | |
C11 | 0.3571 (5) | 0.7794 (3) | 0.4722 (2) | 0.0568 (9) | |
H11 | 0.3241 | 0.8133 | 0.4175 | 0.068* | |
C12 | 0.3841 (5) | 0.6111 (3) | 0.3898 (3) | 0.0577 (9) | |
C13 | 0.3368 (6) | 0.5017 (3) | 0.3975 (3) | 0.0743 (10) | |
C14 | 0.3288 (6) | 0.4347 (4) | 0.3228 (5) | 0.0930 (15) | |
H14 | 0.2959 | 0.3616 | 0.3296 | 0.112* | |
C15 | 0.3693 (7) | 0.4754 (5) | 0.2380 (4) | 0.0916 (16) | |
H15 | 0.3627 | 0.4302 | 0.1868 | 0.110* | |
C16 | 0.4199 (6) | 0.5835 (4) | 0.2282 (3) | 0.0830 (13) | |
H16 | 0.4484 | 0.6111 | 0.1704 | 0.100* | |
C17 | 0.4283 (5) | 0.6505 (3) | 0.3039 (3) | 0.0689 (11) | |
H17 | 0.4642 | 0.7231 | 0.2971 | 0.083* | |
F1 | 0.2925 (4) | 0.4629 (2) | 0.4811 (2) | 0.1113 (10) | |
N1 | 0.3887 (4) | 0.6741 (2) | 0.4711 (2) | 0.0612 (8) | |
H1B | 0.4135 | 0.6418 | 0.5220 | 0.073* | 0.43 (6) |
O1 | 0.4613 (5) | 0.6891 (2) | 0.6408 (2) | 0.0823 (9) | |
H1A | 0.4242 | 0.6584 | 0.5943 | 0.124* | 0.57 (6) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0475 (17) | 0.062 (2) | 0.048 (2) | −0.0027 (16) | −0.0010 (14) | −0.0002 (18) |
C2 | 0.055 (2) | 0.076 (3) | 0.062 (3) | −0.003 (2) | 0.0028 (18) | 0.008 (2) |
C3 | 0.068 (2) | 0.106 (4) | 0.047 (2) | 0.005 (2) | 0.0024 (19) | 0.007 (2) |
C4 | 0.062 (2) | 0.099 (3) | 0.049 (2) | −0.007 (2) | 0.0014 (19) | −0.007 (2) |
C5 | 0.055 (2) | 0.072 (3) | 0.057 (2) | −0.0125 (18) | 0.0069 (17) | −0.010 (2) |
C6 | 0.081 (3) | 0.076 (3) | 0.077 (3) | −0.012 (2) | 0.015 (2) | −0.020 (3) |
C7 | 0.118 (4) | 0.057 (2) | 0.103 (4) | −0.001 (3) | 0.016 (3) | −0.004 (3) |
C8 | 0.127 (4) | 0.062 (3) | 0.081 (3) | 0.013 (3) | −0.003 (3) | 0.006 (2) |
C9 | 0.096 (3) | 0.061 (2) | 0.055 (2) | 0.004 (2) | −0.003 (2) | 0.0001 (18) |
C10 | 0.0468 (18) | 0.056 (2) | 0.053 (2) | −0.0045 (15) | 0.0006 (15) | 0.0017 (18) |
C11 | 0.055 (2) | 0.057 (2) | 0.059 (2) | 0.0004 (17) | −0.0048 (18) | 0.0079 (17) |
C12 | 0.0473 (18) | 0.052 (2) | 0.073 (3) | 0.0021 (16) | −0.0060 (18) | −0.006 (2) |
C13 | 0.062 (2) | 0.056 (3) | 0.104 (2) | 0.0001 (19) | −0.002 (2) | −0.005 (2) |
C14 | 0.074 (3) | 0.055 (3) | 0.151 (5) | −0.001 (2) | −0.011 (3) | −0.010 (3) |
C15 | 0.075 (3) | 0.087 (4) | 0.114 (4) | 0.014 (3) | −0.007 (3) | −0.040 (3) |
C16 | 0.075 (3) | 0.094 (4) | 0.080 (3) | 0.014 (3) | 0.000 (2) | −0.017 (3) |
C17 | 0.067 (2) | 0.070 (3) | 0.070 (2) | 0.007 (2) | 0.001 (2) | −0.008 (2) |
F1 | 0.124 (2) | 0.0774 (17) | 0.133 (2) | −0.0092 (16) | 0.007 (2) | 0.0304 (16) |
N1 | 0.0596 (18) | 0.057 (2) | 0.067 (2) | 0.0015 (15) | −0.0012 (15) | 0.0019 (16) |
O1 | 0.098 (2) | 0.0781 (19) | 0.0710 (19) | 0.0091 (18) | 0.0012 (16) | 0.0213 (16) |
C1—C11 | 1.405 (5) | C9—H9 | 0.93 |
C1—C2 | 1.424 (5) | C11—N1 | 1.306 (4) |
C1—C10 | 1.446 (5) | C11—H11 | 0.93 |
C2—O1 | 1.314 (5) | C12—C17 | 1.380 (5) |
C2—C3 | 1.415 (5) | C12—C13 | 1.384 (5) |
C3—C4 | 1.330 (6) | C12—N1 | 1.413 (4) |
C3—H3 | 0.93 | C13—F1 | 1.347 (5) |
C4—C5 | 1.426 (6) | C13—C14 | 1.363 (6) |
C4—H4 | 0.93 | C14—C15 | 1.365 (7) |
C5—C6 | 1.394 (6) | C14—H14 | 0.93 |
C5—C10 | 1.413 (5) | C15—C16 | 1.378 (7) |
C6—C7 | 1.344 (6) | C15—H15 | 0.93 |
C6—H6 | 0.93 | C16—C17 | 1.375 (6) |
C7—C8 | 1.387 (6) | C16—H16 | 0.93 |
C7—H7 | 0.93 | C17—H17 | 0.93 |
C8—C9 | 1.360 (5) | N1—H1B | 0.86 |
C8—H8 | 0.93 | O1—H1A | 0.82 |
C9—C10 | 1.406 (5) | ||
C11—C1—C2 | 119.3 (3) | C9—C10—C1 | 123.5 (3) |
C11—C1—C10 | 122.0 (3) | C5—C10—C1 | 119.7 (3) |
C2—C1—C10 | 118.7 (3) | N1—C11—C1 | 123.4 (3) |
O1—C2—C3 | 119.4 (4) | N1—C11—H11 | 118.3 |
O1—C2—C1 | 121.3 (4) | C1—C11—H11 | 118.3 |
C3—C2—C1 | 119.3 (4) | C17—C12—C13 | 117.9 (4) |
C4—C3—C2 | 121.6 (4) | C17—C12—N1 | 124.4 (3) |
C4—C3—H3 | 119.2 | C13—C12—N1 | 117.7 (4) |
C2—C3—H3 | 119.2 | F1—C13—C14 | 120.0 (4) |
C3—C4—C5 | 122.1 (4) | F1—C13—C12 | 118.2 (4) |
C3—C4—H4 | 118.9 | C14—C13—C12 | 121.8 (5) |
C5—C4—H4 | 118.9 | C13—C14—C15 | 119.7 (5) |
C6—C5—C10 | 120.1 (4) | C13—C14—H14 | 120.2 |
C6—C5—C4 | 121.4 (4) | C15—C14—H14 | 120.2 |
C10—C5—C4 | 118.5 (4) | C14—C15—C16 | 120.1 (5) |
C7—C6—C5 | 121.2 (4) | C14—C15—H15 | 120.0 |
C7—C6—H6 | 119.4 | C16—C15—H15 | 120.0 |
C5—C6—H6 | 119.4 | C17—C16—C15 | 119.9 (5) |
C6—C7—C8 | 119.9 (4) | C17—C16—H16 | 120.0 |
C6—C7—H7 | 120.1 | C15—C16—H16 | 120.0 |
C8—C7—H7 | 120.1 | C16—C17—C12 | 120.7 (4) |
C9—C8—C7 | 120.4 (4) | C16—C17—H17 | 119.7 |
C9—C8—H8 | 119.8 | C12—C17—H17 | 119.7 |
C7—C8—H8 | 119.8 | C11—N1—C12 | 122.9 (3) |
C8—C9—C10 | 121.7 (4) | C11—N1—H1B | 118.6 |
C8—C9—H9 | 119.2 | C12—N1—H1B | 118.6 |
C10—C9—H9 | 119.2 | C2—O1—H1A | 109.5 |
C9—C10—C5 | 116.7 (3) | ||
C11—C1—C2—O1 | 0.3 (5) | C11—C1—C10—C9 | 0.3 (5) |
C10—C1—C2—O1 | 179.8 (3) | C2—C1—C10—C9 | −179.2 (4) |
C11—C1—C2—C3 | 179.7 (3) | C11—C1—C10—C5 | −179.7 (3) |
C10—C1—C2—C3 | −0.9 (5) | C2—C1—C10—C5 | 0.8 (5) |
O1—C2—C3—C4 | 179.9 (4) | C2—C1—C11—N1 | 1.0 (5) |
C1—C2—C3—C4 | 0.5 (6) | C10—C1—C11—N1 | −178.5 (3) |
C2—C3—C4—C5 | −0.1 (6) | C17—C12—C13—F1 | −179.7 (4) |
C3—C4—C5—C6 | 180.0 (4) | N1—C12—C13—F1 | 2.0 (5) |
C3—C4—C5—C10 | 0.1 (5) | C17—C12—C13—C14 | −1.7 (6) |
C10—C5—C6—C7 | −0.1 (6) | N1—C12—C13—C14 | −180.0 (4) |
C4—C5—C6—C7 | 180.0 (4) | F1—C13—C14—C15 | 178.3 (4) |
C5—C6—C7—C8 | 0.5 (8) | C12—C13—C14—C15 | 0.4 (6) |
C6—C7—C8—C9 | −0.4 (8) | C13—C14—C15—C16 | 0.7 (7) |
C7—C8—C9—C10 | 0.0 (8) | C14—C15—C16—C17 | −0.5 (7) |
C8—C9—C10—C5 | 0.4 (6) | C15—C16—C17—C12 | −0.9 (7) |
C8—C9—C10—C1 | −179.5 (4) | C13—C12—C17—C16 | 1.9 (6) |
C6—C5—C10—C9 | −0.3 (5) | N1—C12—C17—C16 | −179.9 (4) |
C4—C5—C10—C9 | 179.6 (3) | C1—C11—N1—C12 | −176.7 (3) |
C6—C5—C10—C1 | 179.6 (3) | C17—C12—N1—C11 | 30.5 (5) |
C4—C5—C10—C1 | −0.5 (5) | C13—C12—N1—C11 | −151.4 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1A···N1 | 0.82 | 1.82 | 2.535 (4) | 144 |
N1—H1B···O1 | 0.86 | 1.86 | 2.535 (4) | 134 |
Experimental details
Crystal data | |
Chemical formula | 0.57C17H12FNO·0.43C17H12FNO |
Mr | 265.28 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 296 |
a, b, c (Å) | 7.2841 (3), 12.2158 (6), 14.5731 (7) |
V (Å3) | 1296.73 (10) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.73 × 0.31 × 0.10 |
Data collection | |
Diffractometer | Stoe IPDSII |
Absorption correction | Integration (X-RED32; Stoe & Cie, 2002) |
Tmin, Tmax | 0.967, 0.993 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5655, 1477, 951 |
Rint | 0.040 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.047, 0.113, 0.97 |
No. of reflections | 1477 |
No. of parameters | 183 |
No. of restraints | 1 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.23, −0.14 |
Computer programs: X-AREA (Stoe & Cie, 2002), X-RED32 (Stoe & Cie, 2002), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1A···N1 | 0.82 | 1.82 | 2.535 (4) | 144 |
N1—H1B···O1 | 0.86 | 1.86 | 2.535 (4) | 134 |
Acknowledgements
The authors acknowledge the Faculty of Arts and Sciences, Ondokuz Mayıs University, Turkey, for the use of the Stoe IPDSII diffractometer (purchased under grant No. F279 of the University Research Fund).
References
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Schiff bases often exhibit various biological activities and in many cases were shown to have antibacterial, anticancer, anti-inflammatory and antitoxic properties (Lozier et al., 1975). Schiff bases have also been used as versatile ligands in coordination chemistry (Kargar et al., 2009; Yeap et al., 2009). There are two types of intramolecular hydrogen bonds in Schiff bases, namely N—H···O in keto (NH) (Hökelek et al., 2000) and N···H—O in enol (OH) (Odabaşoǧlu et al., 2005) tautomeric forms. In the solid state, while OH tautomeric forms of Schiff bases are predominant in salicylaldimines (Kaitner & Pavlovic, 1996; Yıldız et al.,1998), both NH and OH forms have been found in naphthaldimine Schiff base compounds (Nazır et al., 2000; Karabıyık et al., 2007). Our investigations shows that in the title compound both OH (enol) and NH (keto) tautomers coexist with occupancies of 0.57 (6) and 0.43 (6), respectively. This evidence is also supported by the observed IR vibrational bands given in the experimental section.
An ORTEP-3 (Farrugia, 1997) plot of the molecule of (I) is shown in Fig.1. The C2—O1 [1.314 (5) Å] and C11—N1 [1.306 (4) Å] bond lengths are intermediate between the single and double C—O (1.362 and 1.222 Å, respectively) and C—N bond lengths (1.339 and 1.279 Å, respectively) (Allen et al., 1987). Similar results were observed for 2-[(2,4-dimethylphenyl)iminomethyl]-3,5-dimethoxyphenol (Tanak et al., 2009). The molecule of the title compound is not planar, with a dihedral angle of 32.76 (1)° between naphthalene and benzene rings. The molecular structure is stabilized by O—H···N or N—H···O hydrogen bonds.