(3-{[N-(5-Chloro-2-hydroxyphenyl)oxamoyl]amino}propyl)dimethylazanium perchlorate

In the title compound, C13H19ClN3O3 +·ClO4 −, the 3-(dimethylammonio)propyl group of the cation is disordered over two sets of sites with occupancies 0.772 (6) and 0.228 (6). The cations are joined by pairs of N—H⋯O hydrogen bonds into centrosymmetric dimers and these dimers are assembled into chains along the a-axis direction, also through N—H⋯O hydrogen bonds. The perchlorate anions are linked to the hydroxy groups of the cations by O—H⋯O hydrogen bonds. The positively charged ammonium groups and the anions give rise to folded layers parallel to the ab plane.

In the title compound, C 13 H 19 ClN 3 O 3 + ÁClO 4 À , the 3-(dimethylammonio)propyl group of the cation is disordered over two sets of sites with occupancies 0.772 (6) and 0.228 (6). The cations are joined by pairs of N-HÁ Á ÁO hydrogen bonds into centrosymmetric dimers and these dimers are assembled into chains along the a-axis direction, also through N-HÁ Á ÁO hydrogen bonds. The perchlorate anions are linked to the hydroxy groups of the cations by O-HÁ Á ÁO hydrogen bonds. The positively charged ammonium groups and the anions give rise to folded layers parallel to the ab plane.
In the crystal, the positively charged ammonium N atoms (N3A and N3B) together with the perchlorate anions form a folded layer structure with a quadrilateral pattern (Fig. 2). Such a charge-balanced layer is paralled to a0b plane. Cations related by an inversion center are linked by the hydrogen bonds involving oxamide groups (N2-H2A···O2, Table 3) to form a dimer. These dimers form chains parallel to a direction through the hydrogen bonds involving the ammonium groups ( Fig. 3). The perchlorate ions append to the chains through the hydrogen bonds with phenolic hydroxy groups.

Experimental
The ligand, H 3 chdpoxd, was prepared according to the method proposed by Tao et al., (2003). To a solution of H 3 chdpoxd (0.0299 g, 0.1 mmol) in methanol (10 ml) were added sequentially piperidine (0.2 mmol) and a solution of Cu(ClO 4 ) 2 .6H 2 O (0.0742 g, 0.2 mmol) in methanol (10 ml). The mixture was intensively stirred until the solution became clear, and then 2,9-dimethyl-1,10-phenanthroline (dmphen, 0.0432 g, 0.4 mmol) in methanol (10 ml) was added. Stirring of the reaction mixture was continued at 333 K for 2 h. Although our original goal was to prepare a dinuclear copper(II) complex with chdpoxd 3as a bridge ligand and 2,9-dimethyl-1,10-phenanthroline as a terminal ligand, the colourless crystals of the title compound, (H 4 chdpoxd)ClO 4 , unexpectedly precipitated on the seventh day, after the solution had been left to stand at room temperature.

Refinement
The 3-(dimethylamminio)propyl group of the cation is disordered over two sets of positions, suffixed with A and B. The occupancies were refined freely to 0.772 (6) and 0.228 (6), respectively. The bond lengths C9A-C10A, C10A-C11A and C10B-C11B were restrained to 1.54 Å with DFIX instructionto to avoid the unreasonable geometries. The H atoms on the phenolic hydroxyl and the oxamide group were found in a difference Fourier map and then refined freely except for the restrain on N1-H1A bond length of 0.86 Å. Other H atoms were placed in calculated positions, with C-H = 0.93 supplementary materials sup-2 (aromatic), 0.97 (methylene) and 0.96 (methyl) and N-H = 0.91 Å, and refined using riding model, with U iso (H) = 1.2 U eq , or 1.5 U eq for methyl groups. Fig. 1. The structure of the title compound. The displacement ellipsoids are drawn at the 30% probability levels and H atoms are shown as small spheres of arbitrary radii. Two position of a disordered group are depicted in different styles. Dotted line indicate hydrogen bond.

Special details
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The 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.