Crystal structure and Hirshfeld surface analysis of 2,2′-(phenylazanediyl)bis(1-phenylethan-1-one)

The whole molecule of the title compound is generated by twofold rotational symmetry. In the crystal, molecules are linked by intermolecular C—H⋯O interactions with (12) ring motifs, and C—H⋯π interactions, resulting in ribbons along the c-axis direction. The molecular packing is consolidated by van der Waals interactions between these ribbons.


Structural commentary
The asymmetric unit of the title compound contains half a molecule, the complete molecule being generated by the twofold rotational axis. Atoms N1, C1 and C4 are located on the twofold rotation axis (Fig. 1). The N1 atom has a trigonalplanar geometry, and it is bonded to two C atoms (C5 and C5A) from two symmetry-related 1-phenylethan-1-one groups and atom C1 of the phenyl ring, which is divided by the twofold rotation axis. The phenyl ring (C1-C4/C2A/C3A) attached to the N1 atom and the phenyl rings (C7-C12 and C7A-C12A) of the two symmetry-related 1-phenylethan-1one groups are oriented at 89.65 (6) to each other.
Crystal Explorer17.5 (Turner et al., 2017) was used to perform a Hirshfeld surface analysis and generate the associated two-dimensional fingerprint plots, with a standard resolution of the three-dimensional d norm surfaces plotted over a fixed colour scale of À0.1305 (red) to 1.2546 (blue) a.u (Fig. 4). In the Hirshfeld surface mapped over d norm (Fig. 4), the bright-red spots near atoms O1 and H5A indicate the short C-HÁ Á ÁO contacts (Table 1). Other contacts are equal to or longer than the sum of van der Waals radii.  Table 1 Hydrogen-bond geometry (Å , ).

Figure 3
View of the packing down the c axis showing C-HÁ Á ÁO hydrogen bonds and and C-HÁ Á Á interactions in the title compound. The hydrogen atoms not involved in the hydrogen bonds have been omitted for clarity.

Figure 1
The molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level.
Fingerprint plots ( Fig. 5b-d; Table1) reveal that HÁ Á ÁH (45.5%), CÁ Á ÁH/HÁ Á ÁC (38.2%) and OÁ Á ÁH/HÁ Á ÁO (16.0%) interactions make the greatest contributions to the surface contacts. NÁ Á ÁH/HÁ Á ÁN (0.3%) contacts also contribute to the overall crystal packing of the title compound. The Hirshfeld surface analysis confirms the importance of H-atom contacts in establishing the packing. The large number of HÁ Á ÁH, CÁ Á ÁH/HÁ Á ÁC and OÁ Á ÁH/HÁ Á ÁO interactions suggest that van der Waals interactions and hydrogen bonding play the major roles in the crystal packing (Hathwar et al., 2015). . Like the title compound, the molecule of (I) possesses twofold rotational symmetry. The N atom has a trigonal-planar geometry and is located on the twofold rotation axis. Weak C-HÁ Á ÁO hydrogen bonds connect the molecules, forming a three-dimensional network. The asymmetric unit of (II) contains two independent molecules with similar conformations. In the crystal, N-HÁ Á ÁO and weak C-HÁ Á ÁO hydrogen bonds link the molecules into a three-dimensional supramolecular structure. Weak intermolecular C-HÁ Á Á interactions are also observed. In (III), the C C double bonds adopt an E configuration. In the crystal, pairs of C-HÁ Á ÁO hydrogen bonds link the molecules into inversion dimers.

Synthesis and crystallization
The title compound was synthesized using the reported procedure (He et al., 2014), and pale-yellow needle-like crystals were obtained upon slow evaporation from an ethanol/ water (4:1) homogeneous solution at room temperature.

Special details
Experimental. CrysAlisPro 1.171.41.117a (Rigaku OD, 2021) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm. 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.
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )