Crystal structure of diaqua(3,14-diethyl-2,6,13,17-tetraazatricyclo[16.4.0.07,12]docosane)copper(II) (3,14-diethyl-2,6,13,17-tetraazatricyclo[16.4.0.07,12]docosane)copper(II) tetrabromide dihydrate, [Cu(C22H44N4)(H2O)2][Cu(C22H44N4)]Br4·2H2O

In the title complex, [Cu(C22H44N4)(H2O)2][Cu(C22H44N4)]Br4·2H2O, each of the two complex cations lies about an inversion center. The two macrocyclic rings adopt the most stable trans-III configuration. In the crystal, O—H⋯Br, N—H⋯Br, N—H⋯O and C—H⋯O hydrogen bonds connect the complex cations, bromide anions, semi-coordinating H2O ligands and water solvent molecules, forming a one-dimensional network extending parallel [100].

3,14-Diethyl-2,6,13,17-tetraazatricyclo(16.4.0.0 7,12 )docosane (C 22 H 44 N 4 , L) also contains a cyclam backbone with cyclohexane subunits and ethyl groups at the carbon atoms (Subhan & Choi, 2014). To the best of our knowledge, the preparation and crystal structure for any double metal complex containing the macrocycle L have not been reported. ISSN 2056-9890 Here, we report on the synthesis and structural characterization of the new double Cu II complex, namely, [Cu(L)(H 2 O) 2 ][Cu(L)]Br 4 Á2H 2 O, (I), to determine the configuration of the macrocycles and the bonding properties of the water molecules and bromide anions in the crystal.
chelate rings adopt a gauche conformation and the sixmembered rings are in chair conformations. The cyclohexane rings are also in a chair conformation, with the N atoms in equatorial positions.

Supramolecular features
Extensive hydrogen-bonding interactions occur in the crystal structure of (I); numerical details are given in Table 1

Synthesis and crystallization
Ethyl vinyl ketone (97%), trans-1,2-cyclohexanediamine (99%) and copper(II) bromide (99%) were purchased from Sigma-Aldrich and were used as received. All other chemicals were of analytical reagent grade. 3,14-Diethyl-2,6,13,17-tetraazatricyclo(16.4.0.0 7,12 )docosane (L) was prepared according to a published procedure (Lim et al., 2006). A solution of the macrocycle L (0.184 g, 0.5 mmol) in 10 mL of water was added dropwise to a stirred solution of CuBr 2 (0.113 g, 0.5 mmol) in 10 mL of water. The resulting solution was heated in a water bath for 1 h under stirring at 373 K. After cooling to 298 K, the pH was adjusted to 3.0 by the addition of 1.0 M HBr. The solution mixture was filtered. The filtrate was slowly evaporated at room temperature to yield octahedron-like purple crystals of (I) suitable for X-ray structural analysis.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2. All C-and N-bound H atoms in the complex were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C-H distances of 0.97-0.99 Å , and with an N-H distance of 0.99 Å with U iso (H) values of 1.2 and 1.5U eq , respectively, of the parent atom. The hydrogen atoms of water molecules were assigned based on a difference-Fourier map, and were restrained using DFIX and DANG commands during the least-squares refinement and with U iso (H) values of 1.2U eq of the oxygen atom.

Funding information
This work was supported by a Research Grant of Andong National University. The X-ray crystallography experiment at the PLS-II BL2D-SMC beamline was supported in part by MSIT and POSTECH.  (2) Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq