Diaqua(1,4,8,11-tetraazacyclotetradecane-κ4 N 1,N 4,N 8,N 11)copper(II) didodecanoate dihydrate

The title compound, [Cu(C10H24N4)(H2O)2][CH3(CH2)10CO2]2·2H2O, consists of one cationic copper(II) complex, two dodecanoate anions and two water solvent molecules. The CuII atom is located on an inversion center and is chelated by the four aza N atoms of the neutral 1,4,8,11-tetraazacyclotetradecane (cyclam) ligand and by two water molecules in axial positions, giving an octahedral coordination geometry, distorted as a consequence of the Jahn–Teller effect. The uncoordinated water molecules link the complex cations and the dodecanoate counter-ions through O—H⋯O hydrogen bonding, forming a layer structure parallel to (001). Intermolecular N—H⋯O interactions also occur.

In the complex, the Cu II atom, located on an inversion center, is coordinated to the 1,4,8,11-tetraazacyclotetradecane through the four aza-N atoms forming the basal plane of a distorted octahedra whose apices are occupy by two water molecules. Two solvate water molecules link anion and cations through O-H···O hydrogen bondings ( Fig. 1, Table 1). The relatively long Cu-O(water) distance, 2.455 (1)Å, is a consequence of the Jahn-Teller effect resulting in the distorted octahedron coordination geometry.
O-H···O and N-H···O Hydrogen bonds involving the coordinated and non coordinated water molecules, the carboxylate O atoms as well as the N atoms of the cyclam build up a two dimensionnal network forming a layer parallel to the (0 0 1) plane (Table 1, Fig. 2).

Experimental
An ethanolic solution of cyclam (2.50 mmol, 50 ml) was added to a warm ethanolic solution of dimeric copper(II) dodecanoate (1.25 mmol, 100 ml), forming a clear purple solution. The solution was then gently heated for 2 h. Purple plates formed upon cooling to room temperature. The yield was 60%.

Refinement
All H atoms attached to C atoms and N atom were fixed geometrically and treated as riding on their parent atoms with C-H = 0.98 Å (methyl) or 0.99 Å (methylene) and N-H = 0.93 Å with U iso (H) = 1.2U eq (C or N) or U iso (H) = 1.5U eq (Cmethyl). H atoms of water molecule were located in difference Fourier maps and included in the subsequent refinement using restraints (O-H= 0.89 (1)Å and H···H= 1.42 (2)Å) with U iso (H) = 1.5U eq (O). In the last cycles of refinement they were treated as riding on their parent O atoms.

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.
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.