catena-Poly[[bis(nitrato-κO)cadmium]bis[μ-1,3-bis[(1H-1,2,4-triazol-1-yl)methyl]benzene-κ2 N 4:N 4′]]

In the title compound, [Cd(NO3)2(C12H12N6)2]n, the CdII cation is located on an inversion center and is six-coordinated by four N atoms from four 1,3-bis[(1H-1,2,4-triazol-1-yl)methyl]benzene (L) ligands and two O atoms from two nitrate anions in a slightly distorted octahedral geometry. The ligands link different CdII ions into a ribbon-like structure along [001]. Two O atoms of the nitrate anion are disordered over two sets of sites with site occupancies of 0.575 (8) and 0.425 (8).

In the title compound, [Cd(NO 3 ) 2 (C 12 H 12 N 6 ) 2 ] n , the Cd II cation is located on an inversion center and is six-coordinated by four N atoms from four 1,3-bis[(1H-1,2,4-triazol-1-yl)methyl]benzene (L) ligands and two O atoms from two nitrate anions in a slightly distorted octahedral geometry. The ligands link different Cd II ions into a ribbon-like structure along [001]. Two O atoms of the nitrate anion are disordered over two sets of sites with site occupancies of 0.575 (8) and 0.425 (8).

Related literature
For related structures, see: Meng et al. (2004). For the synthesis of the ligand, see: Du et al. (2008).

Experimental
Crystal data [Cd(NO 3  In recent years, much attention has been paid to the use of nitrogen-containing ligands for constructing supramolecular coordination compounds. The reason is that the supramolecular coordination assemblies have not only a variety of architectures but also have potential applications as functional materials. Recently, a series of supramolcular complexes based on the 1,4-bis(1H-1,2,4-triazol-1-yl-methyl)-benzene ligand were reported (Meng et al., 2004). In this paper, we report the new title compound, synthesized by the reaction of 1,3-bis((1H-1,2,4-triazol-1-yl)methyl)benzene and cadmium dinitrate in an aqueous solution.
In the title compound, [Cd(NO3) 2 (C 12 H 12 N 6 ) 2 ] n , the eight-coordinated Cd II ion is located on an inversion center and is in an octahedral environment defined by four N atoms from ligands forming the equatorial plane (distances Cd-N1 = 2.330 (2) Å and Cd-N4 = 2.328 (2) Å) and two O atoms from two nitrate anions lying on the polar axis with a Cd-O1 distance of 2.479 (5) Å ( Figure 1, Table 1). An infinite ribbon-like structure running along [001] is built up by the cisligands linking these Cd II ions ( Figure 2).

Experimental
The ligand L was synthesized following the reference method (Du et al.,2008). Synthesis of the title compound: L (0.120 g, 0.5 mmol) and Cd(NO3) 2 (0.152 g, 0.5 mmol) were dissolved in a mixed solution of 3 mL ethanol and 3 mL water.
After stirring, the suspension was sealed in a 18 mL Teflon-lined autoclave and heated at 140 °C for 5 days. After slow cooling to room temperature, colorless block crystals were filtered and washed with distilled water (47% yield based on Cd).

Refinement
H atoms bound to C atoms were placed in calculated positions and treated as riding on their parent atoms, with C-H = 0.93 / 0.97 Å (aromatic / methylene) and with U iso (H) = 1.2U eq (C). Two O atoms of the nitrate anion were disordered over two positions with site occupancy of 0.58 for O1 and O2 atoms, and 0.42 for O1′ and O2′ atoms, respectively. The SHELXL ′DFIX′ instruction was used to restrain the N-O bond distances of the disordered nitrate anion to close to 1.22 Å .  The molecular structure of the title compound, showing displacement ellipsoids at the 50% probability level for non-H atoms. Only the main component of the disordered nitrate anion is shown. Symmetry codes: (i) 1-x, 1-y, 1-z; (ii) 1-x, 1-y, -z; (iii) x, y, 1+z.

Figure 2
A portion of the ribbon-like structure in the title compound. H atoms and disordered O atoms have been omitted for clarity. [µ-1,3-bis[(1H-1,2,4-triazol-1-yl) where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.77 e Å −3 Δρ min = −0.68 e Å −3 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 > 2sigma(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 Occ. (