Crystal structure and Hirshfeld surface analysis of 3-[2-(3,5-dimethylphenyl)hydrazinylidene]benzofuran-2(3H)-one

In the crystal, molecules are connected by C—H⋯π and π–π stacking interactions, forming a layer lying parallel to the (11 ) plane.


Chemical context
Hydrazones have many applications in diverse areas, such as in optical data storage, as molecular switches and antimicrobial agents, in non-linear optics, molecular recognition, dye-sensitized solar cells, color-changing materials, catalysis, liquid crystals, etc., mainly because of the azo-to-hydrazo tautomerism/isomerism and the optical properties of -N Nunit Ma et al., 2020Ma et al., , 2021Viswanathan et al., 2019). Not only E/Z isomerization, but also azohydrazone tautomerism is important in organic and the coordination chemistry of hydrazone dyes (Ma et al., 2017a,b;Mahmoudi et al., 2017Mahmoudi et al., , 2018. The design of hydrazone dyes with electron donor or acceptor substituents has led to multidentante ligands, the corresponding coordination compounds of which have been applied effectively as catalysts in oxidation and C-C coupling reactions (Mahmudov et al., 2013;Mizar et al., 2012). Moreover, the functional properties of hydrazones or their metal complexes can be regulated by attaching functional groups to the N-NH-unit (Gurbanov et al., 2020a,b;Kopylovich et al., 2011;Mahmudov et al., 2020;Shixaliyev et al., 2014). Thus, we have attached C O groups and furan and aryl rings to the N-NHmoiety, leading to a new hydrazone compound, (Z)-3-[2-(3,5dimethylphenyl)hydrazinylidene]benzofuran-2(3H)-one, which can form intermolecular interactions.

Figure 1
The molecular structure of the title compound with displacement ellipsoids for the non-hydrogen atoms drawn at the 30% probability level.

Hirshfeld surface analysis
Crystal Explorer17 (Turner et al., 2017) was used to perform a Hirshfeld surface analysis and generate the associated twodimensional fingerprint plots, with a standard resolution of the three-dimensional d norm surfaces plotted over a fixed color scale of À0.0001 (red) to 1.5993 (blue) a.u. (Fig. 5a). All of the disordered H atoms of the C16 methyl group were taken into account together. The shape-index of the Hirshfeld surface is a tool to visualize thestacking by the presence of adjacent red and blue triangles; if there are no adjacent red and/or blue triangles, then there are nointeractions. Fig. 5b clearly indicates that there areinteractions in the title compound. Two-dimensional fingerprint plots for the HÁ Á ÁH, OÁ Á ÁH/ HÁ Á ÁO, CÁ Á ÁH/HÁ Á ÁC and CÁ Á ÁC contacts are presented in Fig. 6. HÁ Á ÁH interactions, which are located in the middle region of the fingerprint plot, contribute the most to overall crystal packing, with 51.2% (Fig. 6b). The OÁ Á ÁH/HÁ Á ÁO contacts contribute 17.9% (Fig. 6c) to the Hirshfeld surface, while the CÁ Á ÁH/HÁ Á ÁC contacts contribute 15.2% (Fig. 6d), resulting in a pair of distinctive wings. The CÁ Á ÁC interactions account for 8.1% of the Hirshfeld surface. The percentage contributions to the Hirshfeld surface including other minor ones are summarized in Table 2.

Figure 5
Hirshfeld surfaces of the title molecule, (a) mapped with d norm in the range À0.0001 to 1.5993 a.u. and (b) plotted over shape-index.
. Compound I crystallizes in the monoclinic space group C2/c with Z = 8. In the crystal of I, pairs of molecules are linked into dimers by N-HÁ Á ÁO hydrogen bonds, forming an R 2 2 (12) ring motif, with the dimers stacked along the a-axis direction. These dimers are connected throughstacking interactions between the centroids of the benzene and furan rings of their 2,3-dihydro-1-benzofuran ring systems. Furthermore, there exists a C-HÁ Á Á interaction that consolidates the crystal packing. Compounds II and IV crystallize in the monoclinic space group P2 1 /c with Z = 4. Compound III crystallizes in the monoclinic space group I2/a with Z = 8 and V crystallizes in the triclinic space group P1 with Z = 2. Compound VI crystallizes in the monoclinic space group P2 1 /c with Z = 4. The E conformation in II, III and V is stabilized by a strong intermolecular N-HÁ Á ÁO interaction. These interactions lead to the formation of dimeric structural arrangements. In the crystal of IV, an intermolecular N-HÁ Á ÁN hydrogen bond results in a helical chain structure along the b-axis direction. Non-classical intermolecular C-HÁ Á ÁN and C-HÁ Á ÁO interactions are also observed in the crystals of II, III, IV and V.

3-[2-(3,5-Dimethylphenyl)hydrazinylidene]benzofuran-2(3H)-one
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.