Crystal structure and Hirshfeld surface analysis of N-{2-[(E)-(4-methylbenzylidene)amino]phenyl}-2-(5-methyl-1-H-pyrazol-3-yl)acetamide hemihydrate

The asymmetric unit of the title compound contains two independent organic molecules which differ primarily in the dihedral angle between the aromatic rings, viz. 7.79 (7) and 29.89 (7)°. In the crystal, the components are linked by Owater—H⋯N, N—H⋯Owater and N—H⋯N hydrogen bonds, forming chains along the [100] direction. The chains are linked by C—H⋯O and C—H⋯N hydrogen bonds, forming layers parallel to the ab plane. Finally, the layers are linked by C—H⋯π interactions, forming a three-dimensional structure.


Structural commentary
The molecular structure of the title compound is illustrated in Fig. 1. The asymmetric unit contains two independent organic molecules (1 and 2) and a water molecule. The organic molecules differ primarily in the dihedral angles between the aromatic rings. In the molecule 1, the C7-C12 benzene ring is inclined to the C14-C19 benzene ring by 7.79 (7) , while the corresponding angle in molecule 2 is 29.89 (7) . The molecule overlay in Fig. 2, a view of inverted molecule 2 on molecule 1, illustrates the difference in the conformations of the two molecules, with an r.m.s. deviation of 0.58 Å for the 25 nonhydrogen atoms.

Figure 1
The asymmetric unit of the title compound, with the labelling scheme and 50% probability ellipsoids. The C-HÁ Á ÁO and C-HÁ Á ÁN hydrogen bonds are shown as black dashed lines and the C-HÁ Á Á(ring) interactions by green dashed lines (see Table 1 for details). Table 1 Hydrogen-bond geometry (Å , ).

Supramolecular features
In the crystal, the three components are linked by O water -HÁ Á ÁN and N-HÁ Á ÁO water hydrogen bonds, and by N-HÁ Á ÁN hydrogen bonds, forming chains propagating along the a-axis direction; see Fig. 3. Full details of the various intra-and intermolecular interactions are given in Table 1. The chains are linked by C-HÁ Á ÁO and C-HÁ Á ÁN hydrogen bonds, forming layers parallel to the ab plane (Fig. 3). Finally the layers are linked by C-HÁ Á Á interactions, forming a threedimensional structure (Fig. 4).  Aldoshin et al., 1995). There is an extremely large difference in the dihedral angles between the two aryl rings in these compounds, viz. 44.36 (5) for POSPET, 16.2 (2) for RIHHOF, 41.81 (14) for RIHHUL and 11.2 (4) in RIHJAT. The dihedral angles between the aromatic rings in the title compound are 7.79 (7) and 29.89 (7) in molecules 1 and 2, respectively.

Hirshfeld surface analysis
The Hirshfeld surface analyse was carried out using Crystal-Explorer17.5 (Turner et al., 2017). The Hirshfeld surfaces and their associated two-dimensional fingerprint plots were used to quantify the various intermolecular interactions in the title compound. A 2D fingerprint graph gives a summary of the intermolecular contacts in the crystal. The Hirshfeld surfaces mapped over d norm , d e and d i are illustrated in Fig. 5. The molecular Hirshfeld surfaces were generated using a standard (high) surface resolution with the three-dimensional d norm A partial view along the a axis of the crystal packing of the title compound. The hydrogen bonds are shown as dashed lines (see Table 1; colour code: molecule 1 is blue, molecule 2 is red).

Figure 4
A view along the a axis of the crystal packing of the title compound. The hydrogen bonds are shown as dashed lines and the C-HÁ Á Á interactions as orange arrows (see Table 1).

Figure 5
The Hirshfeld surface of the title compound mapped over d norm , d i and d e .
surfaces mapped over a fixed colour scale of À0.635 (red) to 1.583 (blue) Å . Fig. 6 illustrates the intermolecular O-HÁ Á ÁN, N-HÁ Á ÁO and C-HÁ Á Á interactions (Table 1) of the title compound with d norm mapped on the Hirshfeld surface. Fig. 7 shows the two-dimensional fingerprint plot of the sum of the contacts contributing to the Hirshfeld surface represented in normal mode. Fig. 8a (HÁ Á ÁH) illustrates the twodimensional fingerprint of the (d i , d e ) points associated with hydrogen atoms. It is characterized by an end point that points to the origin and corresponds to d i = d e = 1.08 Å , which indicates the presence of the HÁ Á ÁH contacts in this study (54%). Fig. 8b (CÁ Á ÁH/HÁ Á ÁC) shows the contacts between the carbon atoms inside the surface and the hydrogen atoms outside the surface of Hirshfeld and vice versa (24%). The OÁ Á ÁH/HÁ Á ÁO (11.5%) plot shows two symmetrical wings on the left and right sides (Fig. 8c). The NÁ Á ÁH/HÁ Á ÁN interactions (6.5%) are visualized in Fig. 8d.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2. All the H atoms were located in difference-Fourier maps and freely refined.        program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2018/1 (Sheldrick, 2015b); molecular graphics: DIAMOND (Brandenburg & Putz, 2012) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL2018/1 (Sheldrick, 2015b), PLATON (Spek, 2009) and publCIF (Westrip, 2010). where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.28 e Å −3 Δρ min = −0.19 e Å −3 Special details Experimental. The diffraction data were collected in three sets of 363 frames (0.5° width in ω) at φ = 0, 120 and 240°. A scan time of 60 sec/frame was used. 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.