Crystal structure and Hirshfeld surface analysis of (2Z)-N,N-dimethyl-2-(pentafluorophenyl)-2-(2-phenylhydrazin-1-ylidene)acetamide

The dihedral angle between the aromatic rings in the title compound is 31.84 (8)°; N—H⋯O and C—H⋯O hydrogen bonds and π–π stacking interactions connect molecules in the crystal, producing a three-dimensional network.


Chemical context
Arylhydrazones containing a (Ph,R)C N-NHR grouping possess controllable E/Z isomerization around the C N double bond, which makes them good candidates for the construction of functional materials (Ma et al., 2021). Control of the supramolecular chemistry of hydrazone ligands and the corresponding complexes may afford multi-dimensional synthons or metallo-organic tectons (Kopylovich et al., 2011;Gurbanov et al., 2020a). The functionalization of arylhydrazone ligands with groups such as -SO 3 H, -COOH, -F, -Cl, etc., can improve the catalytic or biological activity of the corresponding coordination compounds (e.g., Shikhaliyev et al., 2019;Gurbanov et al., 2020b). As part of our ongoing work in this area, we have synthesized the title fluorinated arylhydrazone compound, C 16 H 12 F 5 N 3 O, and determined its crystal structure and analysed its Hirshfeld surface. ISSN 2056-9890

Hirshfeld surface analysis
Crystal Explorer 17.5 was used to calculate the Hirshfeld surfaces and two-dimensional fingerprint plots (Turner et al., 2017). The three-dimensional Hirshfeld surface mapped over d norm in the range À0.52 to 2.23 a.u. is shown in Fig. 3: the H9CÁ Á ÁF1, H16Á Á ÁF2, F3Á Á ÁH10C, H3NÁ Á ÁO1, N3-H3NÁ Á ÁO1 and C14-H14Á Á ÁO1 interactions, which play a key role in the molecular packing, can be correlated with the bright-red patches near F1, F2, F3 and O1 and hydrogen atoms H3N and H14, which highlight their functions as donors and/or acceptors. This may be compared to the Hirshfeld surface mapped over electrostatic potential (Spackman et al., 2008) depicted in the supporting information corresponding to positive electrostatic potential (hydrogen-bond donors) in blue and negative electrostatic potential is indicated in red (hydrogenbond acceptors).
The overall two-dimensional fingerprint map for the title compound is shown in Fig. 4a. The percentage contributions to the Hirshfeld surfaces from various interatomic contacts (Table 2)  The title molecule showing 30% probability displacement ellipsoids. Table 1 Hydrogen-bond geometry (Å , ).

Figure 3
View of the three-dimensional Hirshfeld surface of the title compound plotted over d norm in the range À0.52 to 2.23 a.u.
including NÁ Á ÁH/HÁ Á ÁN, NÁ Á ÁC/CÁ Á ÁN and NÁ Á ÁN contacts account for less than 5.4% of the Hirshfeld surface mapping and presumably have minimal directional impact on the packing. The hydrazide derivative SOJQAL adopts an E conformation with an azomethine N C double bond length of 1.272 (2) Å . The molecular skeleton is approximately planar, the terminal five-and six-membered rings forming a dihedral angle of 5.47 (9) . In the crystal, molecules are linked by N-HÁ Á ÁO and C-HÁ Á ÁO hydrogen bonds into zigzag chains propagating in [100].

Database survey
The molecule of HIXRAJ adopts an E conformation with respect to the azomethine bond. The pyridyl and fluorobenzene rings make dihedral angles of 38.58 (6) and 41.61 (5) respectively with the central C( O)N 2 CC unit, resulting in a non-planar molecule. The intermolecular interactions comprise two classical N-HÁ Á ÁO and N-HÁ Á ÁN hydrogen bonds and four non-classical C-HÁ Á ÁO and C-HÁ Á ÁF hydrogen bonds. These interactions are augmented by a weak interaction between the benzene and pyridyl rings of neighbouring molecules, with a centroid-centroid distance of 3.9226 (10) Å . This leads to a three-dimensional supramolecular assembly in the crystal.
The asymmetric unit of MIHROK03 comprises two independent half-molecules, each residing on a centre of symmetry. The two molecules are essentially planar. In the crystal, weak C-HÁ Á Á interactions join the two symmetryindependent molecules into interlinked chains parallel to [011].
The molecule of ZISSAX adopts an E conformation with respect to the azomethine double bond whereas the N and methyl C atoms are in a Z conformation with respect to the same bond. The ketonic O and azomethine N atoms are cis to each other. The non-planar molecule [the dihedral angle between the benzene rings is 7.44 (11) ] exists in an amido form with a C O bond length of 1.221 (2) Å . In the crystal, a bifurcated N-HÁ Á Á(O,N) hydrogen bond is formed between the amide H atom and the keto O and imine N atoms of an adjacent molecule, leading to the formation of chains propagating along the b-axis direction.
In TINWIX, the aromatic rings are almost perpendicular, making a dihedral angle of 89.26 (5) . The carboxyl group is coplanar with the aromatic ring to which it is attached [dihedral angle = 1.70 (17) Table 2 Percentage contributions of interatomic contacts to the Hirshfeld surface for the title compound.

Contact
Percentage contribution carboxyl groups. In addition, there is an N-HÁ Á ÁO hydrogen bond between the amino group and the carbonyl O atom.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 3. The H atom of the NH group was found from a difference-Fourier map and refined freely. All H atoms bonded to C atoms were positioned geometrically and treated as riding atoms, with C-H = 0.93 or 0.96 Å , and with U iso (H) = 1.2 or 1.5U eq (C). The residual electron density was difficult to model and therefore the SQUEEZE routine (Spek, 2015) in PLATON (Spek, 2020) was used to remove the contribution of the electron density in the solvent region from the intensity data and the solvent-free model was employed for the final refinement. The solvent formula mass and unitcell characteristics were not taken into account during refinement. The cavity of volume ca 255.0 Å 3 (ca 7.6% of the unit-cell volume) contains approximately three electrons.

(2Z)-N,N-Dimethyl-2-(pentafluorophenyl)-2-(2-phenylhydrazin-1-ylidene)acetamide
Crystal data 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.