N,N′-(2-Hydroxypropane-1,3-diyl)bis(2-hydroxybenzamide) monohydrate

In the title hydrate, C17H18N2O5·H2O, the complete organic molecule is generated by a crystallographic mirror plane with one C and one O atom lying on the mirror plane. The O atom of the water molecule has m site symmetry. Two symmetry-related intramolecular O—H⋯O hydrogen bonds complete S(6) rings in the organic molecule. In the crystal, the components are linked into (010) sheets by O—H⋯O and N—H⋯O hydrogen bonds.

In the title hydrate, C 17 H 18 N 2 O 5 ÁH 2 O, the complete organic molecule is generated by a crystallographic mirror plane with one C and one O atom lying on the mirror plane. The O atom of the water molecule has m site symmetry. Two symmetryrelated intramolecular O-HÁ Á ÁO hydrogen bonds complete S(6) rings in the organic molecule. In the crystal, the components are linked into (010) sheets by O-HÁ Á ÁO and N-HÁ Á ÁO hydrogen bonds.
Thanks are due to MESRS and DG-RSDT (Ministé re de l'Enseignement Supé rieur et de la Recherche Scientifique et la Direction Gé né rale de la Recherche -Algeria) for financial support.

Comment
The chelating agents containing in their molecular structures 2-hydroxy-1,3-diaminopropane appear in a variey of ligands such as salicylamides (Kumar & Debashis, 2006) and Schiff bases (Azam et al. 2012) or as mixture of both previous functions in the same molecular structures (Kui et al. 2009). This kind of compounds are very attractive and interesting, especially for their coordinating properties with transition metal ions as those involved in metalloenzymes where, for example, the copper complexes are participating in the process of copper transport in humans (Sarkar, 1999). So, the title compound and its analogs are currently used in the synthesis of mono-and polynuclear manganese complexes to investigate their magnetic properties (Louhibi et al., 2007). However, the resulting complexes are, in this case, often bior polynuclear owing to their corresponding polydentate nature (NNOOO).
Herein we report the synthesis and crystal structure of N,N-Bis-Salicylamide(2-hydroxy-1,3-diaminopropane), (I). The molecule structure of (I), and the atomic numbering used, is illustrated in Fig. 1. The asymmetric unit of (I) consists of one-half of the molecule, with the other half generated by a crystallographic mirror plane.
The crystal packing can be described by alterning layers in zigzag parallel to (100) planes ( Fig. 2) and the water molecule is sandwished betwen these layers. It features O-H···O and N-H···O hydrogen bonds (Fig. 2, Table 1). A O-H···O intramolecular interaction is also observed. These interactions link the molecules within the layers and also link the layers together and reinforcing the cohesion of the structure.

Experimental
90 mg (1.0 mmol) of 2-hydroxy-1,3-diaminopropane was dissolved in 10 ml of absolute ethanol and placed in three necked flask of 50 ml. 396 mg (2.0 mmol) of phenylsalicylate were also dissolved in the same solvent (10 ml absolute ethanol). This solution was added in one portion to the previous solution. The resulting mixture, under nitrogen atmosphere and stirring, was heated to reflux for three hours, after which the reaction mixture was filtered as hot solution.
Yellow prisms were formed after some days by slow evaporation (yield 70%).

Figure 1
The molecular structure of the title compound with displacement drawn at the 50% probability level. Only the contents of the asymmetric unit are numbered.

Figure 2
Alternating layers in zigzag parallel to (100) plane of (I) viewed via c axis showing hydrogen bond as dashed line [O-H···O and N-H···O interactions]. Special details Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles 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.