Chlorido[2,2′-(oxydimethylene)dipyridine]copper(II) perchlorate–aquachlorido[2,2′-(oxydimethylene)dipyridine]copper(II) perchlorate (1/1)

The asymmetric unit of the title compound, [CuCl(C12H12N2O)][CuCl(C12H12N2O)(H2O)](ClO4)2, contains two different discrete cations. In one cation, the CuII ion is coordinated in a slightly distorted square-planar geometry, while in the other the CuII ion is in a slightly distorted square-pyramidal environment. In the crystal structure, there are O—H⋯O hydrogen bonds between coordinated water molecules and perchlorate anions. Both types of cations are linked into one-dimensional chains along the b axis by weak electrostatic Cu⋯Cl interactions, with Cu⋯Cl distances of 2.8088 (16) and 3.2074 (17) Å.

The asymmetric unit of the title compound, [CuCl(C 12 H 12 -N 2 O)][CuCl(C 12 H 12 N 2 O)(H 2 O)](ClO 4 ) 2 , contains two different discrete cations. In one cation, the Cu II ion is coordinated in a slightly distorted square-planar geometry, while in the other the Cu II ion is in a slightly distorted squarepyramidal environment. In the crystal structure, there are O-HÁ Á ÁO hydrogen bonds between coordinated water molecules and perchlorate anions. Both types of cations are linked into one-dimensional chains along the b axis by weak electrostatic CuÁ Á ÁCl interactions, with CuÁ Á ÁCl distances of 2.8088 (16) and 3.2074 (17) Å .

Comment
Derivatives of pyridine play an important role in modern coordination chemistry and some complexes using 2,2'-(oxydimethylene)dipyridine as a ligand have already been reported (Li, 2007(Li, , 2008a. Herein we report the crystal structure of the title compound. The molecular structure of the title compound is shown in Fig. 1. Atom Cu1 is in a slightly distorted square-planar coordination environment and atom Cu2 is coordinated in a slightly distorted square-pyramidal environment with the O atom of the coordinated H 2 O ligand in the apical site. 2,2'-(oxydimethylene)dipyridine acts as a tridentate ligand as in the related Cu II , Zn II and Cd II complexes (Li, 2007(Li, , 2008a. In the crystal structure, there are O-H···O hydrogen bonds between coordinated water molecule and perchlorate ions and both types of cation are linked into one-dimensional chains along the b axis by weak electrostatic Cu···Cl interactions with Cu···Cl distances of 2.8088 (16) and 3.2074 (17) Å (see Fig. 2).

Experimental
An 8ml methanol solution of 2,2'-(oxydimetheylene)dipyridine (0.0386 g, 0.193 mmol) was added to an 8 ml H 2 O solution containing Cu(ClO 4 ) 2 .6H 2 O (0.0730 g, 0.197 mmol), and the mixture was stirred for a few minutes. Then, diluted HCl solution was added into the mixed solution in drops until the pH = 4.0. Blue single crystals were obtained after the solution had been allowed to stand at room temperature for three weeks.

Refinement
H 2 O-bound H atoms were located in a difference Fourier map, and placed in idealized positions with O-H = 0.90 Å and with U iso (H) = 1.5U eq (O); other H atoms were placed in calculated positions with C-H = 0.97 Å for methylene group and C-H = 0.93 Å for pyridyl group with U iso (H) = 1.2U eq (C). All H atoms were refined in a riding-model approximation. Fig. 1. The asymmetric unit of the title complex with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.

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 mat- 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.