catena-Poly[[di-μ-bromido-dicopper(I)]bis[μ-η2,σ1-4-(2-allyl-2H-tetrazol-5-yl)pyridine]]

The title compound, [CuBr(C9H9N5)]n, prepared by the solvothermal treatment of CuBr with 4-(2-allyl-2H-tetrazol-5-yl)pyridine, is a new homometallic CuI–olefin coordination polymer in which dinuclear Cu2Br2 units are linked by the organic olefin ligand 4-(2-allyl-2H-tetrazol-5-yl)pyridine, which acts as a bidentate ligand connecting two neighbouring Cu2Br2 units through the pyridine N atom and the double bond of the allyl group. The coordination of Cu(I) is slightly distorted tetrahedral.

The title compound, [CuBr(C 9 H 9 N 5 )] n , prepared by the solvothermal treatment of CuBr with 4-(2-allyl-2H-tetrazol-5-yl)pyridine, is a new homometallic Cu I -olefin coordination polymer in which dinuclear Cu 2 Br 2 units are linked by the organic olefin ligand 4-(2-allyl-2H-tetrazol-5-yl)pyridine, which acts as a bidentate ligand connecting two neighbouring Cu 2 Br 2 units through the pyridine N atom and the double bond of the allyl group. The coordination of Cu(I) is slightly distorted tetrahedral.

Related literature
For the solvothermal synthesis and related structures, see: Ye et al. (2005Ye et al. ( , 2007.

Experimental
Crystal data [CuBr(C 9  Hydrothermal or solvothermal syntheses can offer some interesting reactions and compounds which can't be obtain through conventional solution techniques. In sealed tube, unstable copper (I) salt can exist under vacuums, and then interesting copper (I) organometallic compound can be prepared. The title compound is obtained through solvothermal treatment of CuBr and 4-(2-allyl-2H-tetrazol -5-yl) pyridine in methanol solvent at 75°C.
The copper(I) is coordinated to two organic ligands and two bridging Br atoms to fulfill its tetrahedral coordination environment (Fig 1).The organic ligand acts as a bidentate ligand connecting two neighbouring Cu 2 Br 2 dinucler units through N atom from pyridine ring and double bond of the allyl group thus leading to an homometallic Cu I olefin coordination polymer developing along the b axis. Unfortunately, the N atoms of the tetrazole ring fail to coordinate to Cu I .

Figures
Fig . 1. The one-dimensional structure of the title compound with the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms have been omitted for clarity. [Symmetry codes: Crystal data [CuBr(C 9

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq  (5)