Bis[5-(pyridin-2-yl-κN)tetrazolido-κN 1]copper(II)

In the title complex, [Cu(C6H4N5)2], the CuII ion lies on an inversion center and is coordinated by two chelating 5-(pyridin-2-yl)tetrazolide ligands in a slightly distorted square-planar coordination geometry. In the crystal, π–π stacking interactions, with centroid–centroid distances in the range 3.4301 (14)–3.4387 (13) Å, link the complex molecules along [101].


Comment
Coordination complexes (polymers) have drawn broad attention in recent decades due to their promising applications in catalysis, sensing and gas adsorption/separation (Yang et al., 2012;Lu et al., 2011). Despite several investigations, a detailed analysis of single crystal structures of coordination complexes is also of importance for the study of specific bonding between supramolecules in the solid state.
We report here a coordination complex, formulated as Cu(pytz) 2 (pytz = 5-(pyridin-2-yl)tetrazolide). The molecular structure of the title compound is shown in Fig. 1. The Cu II ion is located on an inversion center. The pytz ligand coordinates to the Cu II ion via two symmetry related pyridine N atoms and two symmetry related tetrazolide N atoms.

Experimental
The title complex was synthesized by the addition of CuNO 3 (2 mmol) to an ethanol solution of Hpytz (4 mmol). The mixed solution was allowed to evaporated solwly at room temperature, and blue prismatic crystals were isolated in about 15 days. Analysis calculated for C 12 H 8 N 10 Cu: C 40.51, H 2.27, N 39.37%; Found: C 40.48, H 2,21, N 39.30%.

Refinement
The H atoms on carbon were placed in calculated positions [C-H = 0.93 Å (aromatic), and U iso (H) = 1.2U eq (C aromatic )] using a riding model approximation.

Figure 2
Part of the crystal structure indicating π-π stacking interactions along [101] and dashed lines to show closest intermolecular Cu···N contacts.