4-Methoxy-2-[(E)-(phenylimino)methyl]phenol

In the molecule of the title compound, C14H13NO2, the two aromatic rings are oriented at a dihedral angle of 0.78 (20)°; with the exception of two methyl H atoms the molecule is essentially planar. The intramolecular O—H⋯N hydrogen bond results in the formation of a non-planar, six-membered ring, which adopts a flattened-boat conformation. In the crystal structure, intermolecular C—H⋯O hydrogen bonds link the molecules to form parallel networks. There is a C—H⋯π contact between the methyl group and the benzene ring. A π–π contact between the benzene and phenyl rings [centroid–centroid distance = 4.681 (5) Å] is also observed.

In the molecule of the title compound, C 14 H 13 NO 2 , the two aromatic rings are oriented at a dihedral angle of 0.78 (20) ; with the exception of two methyl H atoms the molecule is essentially planar. The intramolecular O-HÁ Á ÁN hydrogen bond results in the formation of a non-planar, six-membered ring, which adopts a flattened-boat conformation. In the crystal structure, intermolecular C-HÁ Á ÁO hydrogen bonds link the molecules to form parallel networks. There is a C-HÁ Á Á contact between the methyl group and the benzene ring. Acontact between the benzene and phenyl rings [centroid-centroid distance = 4.681 (5) Å ] is also observed.
In the molecule of the title compound, (Fig. 1) the bond lengths (Allen et al., 1987) and angles are generally within normal ranges. Rings A (C1-C6) and B (C8-C13) are, of course, planar, and they are oriented at a dihedral angle of 0.78 (20)°; with the exception of two methyl H atoms the molecule is essentially planar. 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 thermochromic properties in the title compound as a result of the planarity of the molecule. The intramolecular O-H···N hydrogen bond (Table 1) results in the formation of a non-planar, six-membered ring C (N1/O1/C7/C8/C13/H1); this adopts a flattened-boat conformation having a total puckering amplitude, Q T , of 0.381 (3) Å (Cremer & Pople, 1975).
In the crystal structure, intermolecular C-H···O hydrogen bonds (Table 1) link the molecules to form a network structure ( Fig. 2), in which they are arranged parallel to each other (Fig. 3). A C-H···π contact (Table 1) between the methyl group and B ring is observed. A π-π contact between the A and B rings Cg1···Cg2 i [symmetry code: (i) x, y -1, z, where Cg1 and Cg2 are the centroids of the rings A and B, respectively, further stabilizes the structure, with a centroid-centroid distance of 4.681 (5) Å.

Experimental
The title compound was prepared by the usual condensation method. Aniline (0.931 g, 10 mmol) was dissolved in methanol (10 ml) and added to a solution of 4-methoxysalicylaldehyde (3.042 g, 20 mmol) in methanol (10 ml). The reaction mixture was stirred for 3 h and left overnight at 298 K. The resulting precipitate was filtered and washed with cold ethanol. It was recrystalized from dichloromethane, dried in a vacuum desiccator and the purity was checked by TLC (yield; 3.854 g, 84%, m.p. 341 K).  Fig. 1. The molecular structure of the title molecule with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. The intramolecular hydrogen bond is shown as a double dashed line.

Special details
Geometry. All e.s. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating Rfactors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.