Crystal structure and Hirshfeld surface analysis of 3-[(1E)-(4-{4-[(E)-(3-hydroxybenzylidene)amino]phenoxy}phenylimino)methyl]phenol

In the crystal, the molecule of the title compound has crystallographically imposed twofold rotation symmetry. The crystal packing consists of layers parallel to the ab plane formed by O—H⋯N and C—H⋯O hydrogen bonds.


Chemical context
Several Schiff bases have been reported for their significant biological activities such as antitumor (Mansouri et al., 2013), anti-inflammatory (Shukla & Mishra, 2019), antibacterial (Van Zee & Coates, 2015) or antimicrobial (Pagadala et al., 2015). Schiff bases are also used as versatile components in nucleophilic addition with organometallic reagents and in cycloaddition reactions (Mohan et al., 2012). These findings prompted us to investigate the crystal structure of the title compound.

Structural commentary
The molecule of the title compound has crystallographically imposed twofold rotation symmetry (Fig. 1). The dihedral angle between the two unique benzene rings is 40.68 (6) while the dihedral angle between the two central benzene rings is 77.71 (6) . Bond lengths are typical for this kind of compounds.

Figure 4
A view of the three-dimensional Hirshfeld surface for the title compound, plotted over d norm in the range À1.1242 to 1.4437 a.u. In the crystal of NIBRIC, strong N-HÁ Á ÁO hydrogen bonds form zigzag chains of molecules along the b-axis direction. Weaker C-HÁ Á Á and offsetstacking interactions also contribute to the packing. For NIBROI, pairs of strong O-HÁ Á ÁO hydrogen bonds form centrosymmetric dimers that enclose R 2 2 (18) rings. These combine with weaker C-HÁ Á ÁCl hydrogen bonds, which also generate centrosymmetric dimers, but with R 2 2 (14) motifs. Inversion-related C-HÁ Á Á contacts lead to the formation of sheets of molecules parallel to (120), which are stacked approximately along the baxis direction. In the crystal of AFOPUI, molecules are linked by C-HÁ Á ÁO interactions, forming two-dimensional sheets parallel to the bc plane. In the structure of SABKOX, the hydroxy H atom is involved in a strong intramolecular O-HÁ Á ÁN hydrogen bond, generating a S(6) ring. The molecular structure of MUCDIY is stabilized by an intramolecular O-HÁ Á ÁN hydrogen bond, which generates a six membered ring.

Synthesis and crystallization
Condensation of 1 mmol of 4,4 0 -oxydibenzaldehyde (226 mg) with 2 mmol of 3-aminophenol (218 mg) in ethanol under reflux for 4 h afforded the crude product of the title compound. The product was crystallized from ethanol by slow evaporation to obtain good quality crystals for X-ray diffraction. Yield 82%.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 3. All H atoms were located in a difference-Fourier map and refined freely.

Funding information
The support of NSF-MRI grant No. 1228232 for the purchase of the diffractometer and Tulane University for support of the Tulane Crystallography Laboratory are gratefully acknowledged.
Acta Cryst. (2021). E77, 266-269 research communications    Extinction correction: SHELXL 2016/6 (Sheldrick, 2015b), Fc * =kFc[1+0.001xFc 2 λ 3 /sin(2θ)] -1/4 Extinction coefficient: 0.0031 (2) Special details 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 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 > 2sigma(F 2 ) is used only for calculating R-factors(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.