Crystal structures and the Hirshfeld surface analysis of (E)-4-nitro-N′-(o-chloro, o- and p-methylbenzylidene)benzenesulfonohydrazides

The crystal structures of three N′-(arylidene)4-nitrobenzenesulfonohydrazides, namely, (E)-4-nitro-N′-(2-chlorobenzylidene)benzenesulfonohydrazide (I), (E)-4-nitro-N′-(2-methylbenzylidene) benzenesulfonohydrazide (II) and (E)-4-nitro-N′-(4-methylbenzylidene)benzenesulfonohydrazide (III), have been studied to investigate the effect of the nature and site of substitutions on the structural parameters and the supramolecular features in these compounds. Hirshfeld surface analysis was also carried out to examine the contributions of the various atom–atom interactions in the crystal packing of the three compounds.


Chemical context
Sulfonyl hydrazides have been used extensively to synthesize new Schiff bases owing to the presence of two chemically and biologically important sulfonyl and hydrazine moieties (Murtaza et al., 2016). Reactions of hydrazines with other functional groups produce compounds with unique physical and chemical characteristics (Xavier et al., 2012). Hydrazones derived from the condensation reactions of hydrazides with aldehydes show excellent biological properties (Kü çü kgü zel et ISSN 2056ISSN -9890 al., 2006. As a result of the ease of the electron-transport mechanism through the -conjugated framework, the azomethine-bridged benzene derivatives exhibit excellent optical non-linearities (Manivannan & Dhanuskodi, 2004). Organic polymers containing the azomethine group are known to have good mechanical strength (Morgan et al., 1987) and high thermal stability (Catanescu et al., 2001). As part of our continuing studies to explore the effect of the nature and site of substituents on the crystal structures of sulfonyl hydrazide derivatives (Salian et al., 2018), we report herein the synthesis, crystal structures and Hirshfeld surface analyses of the title compounds, (E)-4-nitro-N 0 -(2-chlorobenzylidene)benzenesulfonohydrazide (I), (E)-4-nitro-N 0 -(2-methylbenzylidene)benzenesulfonohydrazide (II) and (E)-4-nitro-N 0 -(4-methylbenzylidene)benzenesulfonohydrazide monohydrate (III).

Figure 3
Molecular structure of compound (III), showing the atom labelling and displacement ellipsoids drawn at the 30% probability level.

Supramolecular features
In the crystals of the title compounds there are significant difference in the hydrogen-bonding interactions. In the crystal of the ortho-chloro-substituted compound (I), molecules are linked via N-HÁ Á ÁO hydrogen bonds, forming C4 chains along the a-axis direction (Table 1 and Fig. 4). These chains are interconnected by weak C-HÁ Á ÁO hydrogen bonds, generating layers parallel to the ab plane (Table 1 and Fig. 5). In the crystal of the ortho-methyl-substituted compound (II), the amino H atom shows bifurcated N-HÁ Á ÁO(O) hydrogen bonding with both the O atoms of the nitro group, generating chains with a C(9) motif that propagate along the b-axis direction (Table 2 and Fig. 6). These chains are linked by C-HÁ Á ÁO hydrogen bonds, resulting in the formation of a threedimensional framework ( A partial view along the c axis of the crystal packing of compound (I), with hydrogen bonds shown as dashed lines. Table 1 Hydrogen-bond geometry (Å , ) for (I). Symmetry codes: (i) x À 1; y; z; (ii) x þ 1; y; z þ 1.

Figure 5
The crystal packing of compound (I), viewed along the c axis, with hydrogen bonds shown as dashed lines.

Figure 6
A partial view along the a axis of the crystal packing of compound (II), with hydrogen bonds shown as dashed lines.
presence of the water molecule of crystallization has an important effect on the crystal packing. The molecules of compound (III) are bridged by the water molecule, via Ow-HÁ Á ÁO and N-HÁ Á ÁOw hydrogen bonds, forming layers lying parallel to the bc plane that are reinforced by C-HÁ Á ÁO hydrogen bonds (Table 3 and Fig. 8).

Figure 8
The crystal packing of compound (III), viewed along the b axis, with hydrogen bonds shown as dashed lines.

Figure 7
The crystal packing of compound (II), viewed along the a axis,with hydrogen bonds shown as dashed lines.

Figure 9
View of the Hirshfeld surface mapped over d norm for (a) (I), (b) (II) and (c) (III).
distances observed in these compounds [Tables 1, 2 and 3 for (I), (II) and (III), respectively]. These interactions are the major contributor in (I) and (II) [35.0% in (I) and 37.3% in (II)] followed by HÁ Á ÁH contacts [17.5% in (I) and 28.4% in (II)]. In (III), HÁ Á ÁH interactions make the largest contribution to the Hirshfeld surface (37.2%), followed by OÁ Á ÁH/ HÁ Á ÁO contacts (32.0%). The HÁ Á ÁH interactions appear as a short single peak at d e + d i $2.2 Å in the fingerprint plot of (III) (see Fig. 10c). The distinct pair of wings corresponds to CÁ Á ÁH/HÁ Á ÁC contacts, which are the third largest contributor to the Hirshfeld surfaces in all three compounds [17.3% in (I), 13.4% in (II) and 11.0% in (III)]. A significant difference is in the percentage contribution from CÁ Á ÁC contacts found for the three compounds. They are characterized by two overlapping broad peaks in the fingerprint plot for (II) (see Fig. 10b Table 4.

Synthesis of 4-nitrobenzenesulfonohydrazide
Hydrazine hydrate (99%, 5 ml) was added to 4-nitrobenzenesulfonyl chloride (0.01 mol), dissolved in ethanol (30 ml) at 273 K under constant stirring. The stirring continued for 15 min at 273 K and then at 303 K for 3 h. The reaction mixture was then concentrated by evaporating off the excess ethanol. The solid product obtained, i.e. 4-nitrobenzenesulfonohydrazide, was washed with cold water and dried.

Synthesis of the title compounds (I), (II) and (III)
The title compounds were synthesized by refluxing the mixtures of 4-nitrobenzenesulfonohydrazide (0.01 mol) and 0.01 mol of 2-chlorobenzaldehyde for (I), 2-methylbenzaldehyde for (II), and 4-methylbenzaldehyde for (III), in ethanol (30 ml) and two drops of glacial acetic acid for 4 h. The reaction mixtures were cooled to room temperature and concentrated by evaporating off the excess of solvent. The solid products obtained were washed with cold water, dried and recrystallized to constant melting points from ethanol. Purity of the compounds was checked by TLC. All three compounds were characterized by measuring their IR, 1 H and 13 C NMR spectra.
Single crystals of the title compounds used for the singlecrystal X-ray diffraction analyses were obtained by slow evaporation of the solvent in their DMF solutions at room temperature.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 5. The C-bound H atoms were positioned with idealized geometry and refined using a riding model with the aromatic C-H = 0.93 Å . The amino H atoms were refined with an N-H distance restraint of 0.86 (2) Å . For (III), the H atoms of the water molecule were refined with the O-H distance restrained to 0.82 (2) Å . All H atoms were refined with isotropic displacement parameters set at 1.2U eq (C-aromatic, N, O) and 1.5U eq (C-methyl). For (I), the low angle reflection (0 2 1) had a poor agreement with its calculated value and was omitted from the refinement.

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq C1 0.1811 ( where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.19 e Å −3 Δρ min = −0.28 e Å −3 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.