Bis{2-[(2-benzoylhydrazin-1-ylidene)methyl]-6-methoxyphenolato}iron(III) chloride monohydrate

In the title mononuclear iron(III) complex, [Fe(C15H13N2O3)2]Cl·H2O, the FeIII atom has a distorted octahedral geometry and is six-coordinated by four O atoms and two N atoms from two ligands. In the crystal structure, the complex cations, Cl− anions and water molecules are connected into a chain along [100] through N—H⋯O, O—H⋯Cl and N—H⋯Cl hydrogen bonds. Two adjacent chains are linked by O—H⋯O hydrogen bonds.

In the title mononuclear iron(III) complex,  O 3 ) 2 ]ClÁH 2 O, the Fe III atom has a distorted octahedral geometry and is six-coordinated by four O atoms and two N atoms from two ligands. In the crystal structure, the complex cations, Cl À anions and water molecules are connected into a chain along [100] through N-HÁ Á ÁO, O-HÁ Á ÁCl and N-HÁ Á ÁCl hydrogen bonds. Two adjacent chains are linked by O-HÁ Á ÁO hydrogen bonds.

Comment
Studies of acylhydrazone Schiff base and the dependence of their chelation mode with transition metal ions have been of significant interest. On one hand, their metal compounds have been reported to act as enzyme inhibitors (Dilworth, 1976) and are useful due to their pharmacological applications (Merchant & Clothia, 1970). On the other hand, it seems to be a good candidate for catalytic oxidation studies because of their stability to resist oxidation (Pickart et al., 1983). These findings have triggered the exploration of new molecular clusters based on acylhydrazone Schiff base. During the last several years, the crystal structures of metal compounds with 3-methoxysalicylaldehyde benzoylhydrazide have been attracted tremendous interest (Gao et al., 1998;Monfared et al., 2007;Yu et al., 2010). As a continuation of our effort in this system, the preparation and crystal structure of the title Schiff base iron(III) compound are reported here.
The molecular structure of the title compound is illustrated in Fig. 1, which consists of one mononuclear [Fe(C 15 H 13 N 2 O 3 ) 2 ] + cation, one Clanion and one water molecule. The Fe III atom has a distorted octahedral geometry and is six-coordinated by four O atoms and two N atoms from two ligands (Table 1) Table 2).

Experimental
The 3-methoxysalicylaldehyde benzoylhydrazide ligand (H 2 L) was prepared in a similar manner according to the reported procedures (Pouralimardan et al., 2007;Sacconi, 1954). The title compound was synthesized by adding FeCl 3 .6H 2 O (27.0 mg, 0.1 mmol) to a solution of H 2 L (27.3 mg, 0.10 mmol) in methanol (15 ml). The resulting mixture was stirred for 3 h at room temperature to afford a dark brown solution and then filtered. The filtrate was allowed to stand at room temperature for about three weeks and black crystals were produced at the bottom of the vessel on slow evaporation of methanol.

Refinement
All H atoms were placed in calculated positions and refined using a riding model, with C-H = 0.93 (aromatic), 0.96 (methyl) Å and N-H = 0.86 Å and with U iso (H) = 1.2(1.5 for methyl)U eq (C, N). Water H atoms were located in a difference Fourier map and refined as riding, with O-H = 0.85 Å and U iso (H) = 1.2U eq (O). Fig. 1. Molecular structure of the title compound. H atoms are omitted for clarity. Displacement ellipsoids are drawn at the 30% probability level.