2-[1-(3-Aminophenylimino)ethyl]phenol

The title compound, C14H14N2O, exists as the enol–imine tautomer. A strong intramolecular hydrogen bond between O and N atoms forms a six-membered ring with an S(6) graph-set motif, which is approximately coplanar with the phenol ring, the interplanar angle being 3.4 (3)°. In the crystal, intermolecular C—H⋯O hydrogen bonds and N—H⋯π interactions link the molecules into infinite chains along [100].


Comment
Schiff bases are some of the most widely used chelating ligands in the field of metal-organic coordination chemistry (Blagus et al., 2010). The Schiff bases derived from ortho hydroxy aldehydes or ketons and aromatic diamines often have photochromic and thermochromic characteristics (Hadjoudis & Mavridis 2004). In this work we report the preparation and the crystal and molecular structure of a novel ketimine Schiff base 2-[1-(3-aminophenylimino)ethyl]phenol (Scheme 1).
The presence of intramolecular O1-H···N1 hydrogen bond [2.540 (2) Å] shows unequivocally that the molecular conformation of compound (1) in the crystalline state is in the enol-imino form. As shown in Figure 2, the Schiff base molecules link mutually in an one-dimensional chain forming a graph-set motif C(5) in the notation of Bernstein et al., (1995)  refers to the C9-C14 aromatic system centroid). All bond lengths are within the standard values (Allen et al., 1987) and are comparable with the similar ketimine Schiff bases as cited above (Blagus & Kaitner, 2007).

Experimental
The title compound was prepared by refluxing a methanolic solution of m-phenylendiamine (540 mg, 5 mmol) and 2-hydroxyacetophenone (1.25 ml, 10 mmol) for 4 h at the temperature of 80 °C. The water formed during the reaction was removed by a Dean-Stark trap. After cooling, the brown solid precipitate was filtered. Diffraction quality crystals were obtained by slow evaporation from ether solution.

Refinement
All N-and O-bound H atoms were located in the difference Fourier map. The position and the isotropic thermal parameters of N-bound H atoms were refined, while the O-bound H atom was treated as riding atom. Aromatic H atoms were placed in calculated positions and treated as riding on their parent C atoms with C-H = 0.93 Å and U iso (H) = 1.2 U eq (C) for Csp2.
In the absence of significant anomalous scattering effects Friedel pairs have been merged. Fig. 1. ORTEPIII molecular structure of (I) showing our atom-labelling scheme. Thermal ellipsoids are drawn at the 50% probability level. The intramolecular hydrogen bonds O-H···N is shown as thin line.