Crystal structure of (E)-N′-(4-chlorobenzylidene)-4-methylbenzenesulfonohydrazide: a hexagonal polymorph

The title compound, C14H13ClN2O2S, crystallized in the enantiomorphic defining hexagonal space group P61 [Flack parameter = −0.02 (7)]. The partially hydrated form of the same compound, crystallizing in the triclinic space group P-1, has been reported previously [Kia et al. (2009b). Acta Cryst. E65, o1119], as has the crystal structure of the bromo derivative, also crystallizing in the space group P-1 [Kia et al. (2009a). Acta Cryst. E65, o821]. The title molecule is non-planar with the planes of the benzene rings being inclined to one another by 76.62 (13)°, and has an E conformation about the C=N bond. In the crystal, molecules are linked via N—H⋯O hydrogen bonds forming 61 helical chains running along [001]. The chains are linked via C—H⋯O hydrogen bonds, C—H⋯π interactions and short Cl⋯O [3.015 (3) Å] interactions, forming a three-dimensional structure.


Related literature
For the biological activities of hydrazones, see: Ajani et al. (2010). For the crystal structure of the triclinic polymorph, which crystallized with two independent molecules in the asymmetric unit, one of which was disordered, and with 0.15 of a water molecule, see: Kia et al. (2009b). For the crystal structure of the bromo derivative, also crystallizing in space group P1, see: Kia et al. (2009a  Hydrogen-bond geometry (Å , ).

S1. Comment
The title compound was obtained by a Schiff base condensation reaction between 4-chlorobenzaldehyde and tosyl hydrazide. Hydrazones have received much attention recently due to their biological activities (Ajani et al., 2010). The crystal structure of the triclinic polymorph, that crystallized with two independent molecules in the asymmetric unit, one of which was disordered, and with 0.15 of a water molecule, has been reported (Kia et al., 2009b), as has the crystal structure of the bromo derivative, also crystallizing in space group P1 (Kia et al., 2009a).

S2. Experimental
4-chlorobenzaldehyde (0.140 g, 1 mmol) and tosyl hydrazide (0.186 g, 1 mmol) were dissolved in ethanol and chloroform (4:1). The reaction mixture was heated under reflux for 3 h and cooled gradually to room temperature. Prismatic colourless crystals were obtained by slow evaporation of an ethanol solution at room temperature.

S3. Refinement
The NH H atom was located in a difference Fourier map and freely refined. The C-bound H atoms were positioned geometrically and treated as riding on their parent atoms with C-H = 0.93 Å (aromatic) and 0.96 Å (methyl) and with U iso (H) = 1.5U eq (C) for the methyl H atoms and = 1.2U eq (C) for other H atoms.
supporting information

Figure 1
The molecular structure of the title compound, with atom labelling. The displacement ellipsoids are drawn at the 30% probability level.

Figure 2
A view along the c axis of the crystal packing of the title compound. The N-H···O and C-H···O hydrogen bonds are indicated by dashed lines (see Table 1  where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.12 e Å −3 Δρ min = −0.16 e Å −3 Extinction correction: SHELXL97 (Sheldrick, 2008), Fc * =kFc[1+0.001xFc 2 λ 3 /sin(2θ)] -1/4 Extinction coefficient: 0.0026 (4) Absolute structure: Flack (1983), 1257 Friedel pairs Absolute structure parameter: −0.02 (7) Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > σ(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.  (17)