Bis[2-(1H-benzotriazol-1-yl)-1H-benzimidazol-1-ido]diethanolcadmium

In the title complex, [Cd(C13H8N5)2(C2H5OH)2], the CdII cation is located on an inversion center and coordinated by two deprotonated 2-(1H-benzotriazol-1-yl)-1H-benzimidazol-1-ide (L) ligands and two ethanol molecules in a distorted N4O2 octahedral geometry. In the L ligand, the dihedral angle between benzoimidazole and benzotriazole ring systems is 10.8 (3)°. In the crystal, the complex molecules are connected by O—H⋯N hydrogen bonds; intermolecular π–π stacking is also observed [centroid–centroid distances of 3.668 (5) Å between triazole and benzene rings and 3.780 (5) Å between imidazole rings].


Comment
Over the past decades, we lay much stress on the complexation of metal ions by nitrogen heterocyclic compounds as their applications in the areas of optical, lectronic properties and magnetice (Zhou et al., 2006;Batten & Robson, 1998;Zaworotko, 1994).
The title compound possesses the benzotriazole and the benzimidazole rings and can offer possibilities to form complicated coordination complexes (Wu et al. 2009). In the crystal, the asymmetric unit contains one half Cd 2+ cation, one organic L ligands and one ethanol molecules. The Cd 2+ is coordinated by four N atoms from two different L ligands and two O atoms from two ethanol molecules. Molecules are connected by O-H···N hydrogen bonds and π-π interactions [centroid-centroid distance = 3.668 (5) and 3.780 (5) Å] involving related triazole, imidazole and benzene rings.

Experimental
To a yellow solution of L (35 mg, 0.15 mmol) and Cd(NO 3 ) 2 (52.3 mg, 0.3 mmol) in ethanol (15 ml) were placed in a Teflon lined stainless steel autoclave and heated at 120 °C for 3 days under autogenous pressure. Then it was allowed to cool to room temperature. Stick-shaped crystals were collected in 50% yield. The crystals were repeatedly washed with ethanol and air-dried.

Refinement
Ethanol H atom was located in a difference Fourier map and positional parameters were refined, U iso (H) = 1.5U eq (O). The C-bound H atoms were included in calculated position and refined in riding-model approximation with C-H = 0.93 Å, U iso (H)= 1.2U eq (C).  The molecular structure of the title compound with the atom numbering. Displacement ellipsoids are drawn at the 50% probability level.

Figure 2
The crystal packing of the title compound, viewed along the a axis. 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.

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