(E)-4-Chloro-N′-(4-hydroxybenzylidene)benzohydrazide

The molecule of the title compound, C14H11ClN2O2, displays a trans configuration with respect to the C=N double bond. The dihedral angle between the two benzene rings is 12.8 (3)°. In the crystal structure, molecules are linked through intermolecular O—H⋯O and N—H⋯O hydrogen bonds and C—H⋯π interactions, forming a three-dimensional network.

The molecule of the title compound, C 14 H 11 ClN 2 O 2 , displays a trans configuration with respect to the C N double bond. The dihedral angle between the two benzene rings is 12.8 (3) . In the crystal structure, molecules are linked through intermolecular O-HÁ Á ÁO and N-HÁ Á ÁO hydrogen bonds and C-HÁ Á Á interactions, forming a three-dimensional network.

Experimental
Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97.  (Musie et al., 2001;Bernardo et al., 1996;Paul et al., 2002). Recently, we have reported a few Schiff base compounds (Yang, 2007(Yang, , 2008a. As a further investigation of this work, the crystal structure of the title compound is reported here. The molecule of the title compound displays a trans configuration with respect to the C═N double bond (Fig. 1). The dihedral angle between the two benzene rings is 12.8 (3)°. All the bonds are within normal ranges (Allen et al., 1987). The In the crystal structure, molecules are linked through intermolecular O-H···O and N-H···O hydrogen bonds, and C-H···π interactions (Table 1), forming a three-dimensional network (Fig. 2).
Experimental 4-Hydroxybenzaldehyde (0.1 mmol, 12.2 mg) and 4-chlorobenzohydrazide (0.1 mmol, 17.0 mg) were dissolved in MeOH (10 ml). The mixture was stirred at room temperature to give a clear colourless solution. Crystals of the title compound were formed by gradual evaporation of the solvent over a period of 5 days at room temperature.

Refinement
Atom H2A was located in a difference Fourier map and refined isotropically, with N-H distance restrained to 0.90 (1) Å and with a U iso of 0.08 Å 2 . Other H atoms were placed in idealized positions and constrained to ride on their parent atoms, with O-H distance of 0.82 Å, C-H distances of 0.93 Å, and with U iso (H) = 1.2U eq (C) and 1.5U eq (O).

Special details
Geometry. All e.s. 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 Rfactors(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.