Crystal structure of trans-aqua(perchlorato-κO)bis(propane-1,3-diamine-κ2 N,N′)copper(II) perchlorate

In the title compound, the CuII atom has a distorted octahedral coordination sphere coordinated by the N atoms of two propane-1,3-diamine ligands in the equatorial plane. The axial positions are occupied by a water O atom and an O atom of a disordered perchlorate anion [occupancy ratio 0.631 (9):369 (9)].

In the title compound, [Cu(ClO 4 )(C 3 H 10 N 2 ) 2 (H 2 O)]ClO 4 , the Cu II atom has a distorted octahedral coordination sphere and is coordinated by the N atoms of two propane-1,3-diamine ligands in the equatorial plane. The axial positions are occupied by a water O atom and an O atom of a disordered perchlorate anion [occupancy ratio 0.631 (9):0.369 (9)]. In the crystal, the various components are linked via O-HÁ Á ÁO, N-HÁ Á ÁO and C-HÁ Á ÁO hydrogen bonds, forming sheets lying parallel to (001).

Chemical context
There have been numerous reports of bis(propane-1,3-diamine)copper(II) complexes, essentially with the copper atom coordinated by the N atoms of the ligands in the equatorial plane of the copper octahedral coordination sphere and with two identical O-containing ligands in the axial positions, for example, trans-diaquabis(propane-1,3-diamine-2 N,N 0 )copper(II) dithionate (Kim et al., 2003) and bis[aqua(1,3-diaminopropane-2 N,N 0 )]copper(II) difluoride (Emsley et al., 1988). In order to further develop the coordination chemistry of such copper complexes, we report herein on the synthesis and crystal structure of the title complex, which has two different ligands in the axial positions of the octahedral coordination sphere of the copper atom.

Structural commentary
The molecular structure of the title complex is illustrated in Fig. 1. The Cu II atom has a distorted octahedral coordination sphere, reflecting the characteristic Jahn-Teller distortion. It is coordinated by the N atoms of two propane-1,3-diamine ligands in the equatorial plane with Cu-N bond lengths varying between 2.003 (4)-2.023 (3) Å . The axial positions are ISSN 1600-5368 occupied by the water O9 atom and by atom O7 of a disordered perchlorate anion [occupancy ratio 0.631 (9):0.369 (9)], with Cu-O bond lengths of 2.585 (6) and 2.680 (10) Å , respectively.

Synthesis and crystallization
The complex was prepared by mixing copper(II) perchlorate hexahydrate with 1,3-diaminopropane in a (1:2) molar ratio. Cu(ClO 4 ) 2 Á6H 2 O (3.7 g, 1 M) was dissolved in 15 ml of warm water. After an hour, about 10 ml of an ethanol solution of 1,3diaminopropane (1.48 g, 2M) was added dropwise with continuous stirring. This solution was then filtered to remove

Figure 2
A view along the a axis of the crystal structure of the title compound. O-HÁ Á ÁO and N-HÁ Á ÁO hydrogen bonds are shown as dashed lines (see Table 1 for details; the minor components of the disordered coordinating perchlorate anion and the C-bound H atoms have been omitted for clarity) any impurities and the solution was kept over P 2 O 5 in a desiccator. Finally, violet-purple-coloured crystals suitable for X-ray diffraction analysis were harvested and washed repeatedly with cold water (yield 70%).

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2. The water H atoms were located in a difference Fourier map and refined with a distance restraint, O-H = 0.90 (2) Å , and with U iso (H) = 1.5U eq (O). The N -and C-bound H atoms were positioned geometrically and allowed to ride on their parent atoms, with N-H = 0.90 and C-H = 0.97 Å , and with U iso (H) = 1.2U eq (N,C). The disordered coordinating perchlorate anion, involving atom Cl2, was refined with an occupancy ratio of 0.631 (9)

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.