catena-Poly[[dichloridomercury(II)]-μ-1,4-bis[2-(pyridin-4-yl)ethynyl]benzene-κ2 N:N′]

In the polymeric title compound, [HgCl2(C20H12N2)]n, the HgII atom is located on a twofold rotation axis and the benzene ring of the bidentate bridging 1,4-bis[2-(pyridin-4-yl)ethynyl]benzene (L) ligand is located about a twofold rotation axis. The HgII atom is coordinated by two N atoms of two different L ligands and by two chloride ions in a distorted tetrahedral geometry. The dihedral angle between the coordinating pyridine and the benzene ring is 12.8 (2)°. The result of the bridging is the formation of a zigzag chain running parallel to [102]. The chains pack with no specific intermolecular interactions between them.

In the polymeric title compound, [HgCl 2 (C 20 H 12 N 2 )] n , the Hg II atom is located on a twofold rotation axis and the benzene ring of the bidentate bridging 1,4-bis[2-(pyridin-4-yl)ethynyl]benzene (L) ligand is located about a twofold rotation axis. The Hg II atom is coordinated by two N atoms of two different L ligands and by two chloride ions in a distorted tetrahedral geometry. The dihedral angle between the coordinating pyridine and the benzene ring is 12.8 (2) . The result of the bridging is the formation of a zigzag chain running parallel to [102]. The chains pack with no specific intermolecular interactions between them.

Refinement
Hydrogen atoms were included in calculated positions and treated as riding on their parent C atoms with C-H = 0.95Å and U iso (H) = 1.2U eq (C). The maximum and minimum residual electron density peaks of 2.15 and 1.73 eÅ -3 , respectively, were located 0.93 Å and 1.00 Å from the Hg atom.  The coordination mode of the title complex, with displacement ellipsoids drawn at the 50% probability level. All H atoms have been omitted for clarity. [Symmetry codes: (#1) -x+1, y, -z+1/2; (#2) -x, -y+3, z+1.]

Figure 2
The zigzag chain of the complex. View down the c axis, with displacement ellipsoids drawn at the 50% probability level.
All hydrogen atoms are omitted for clarity.

catena-Poly[[dichloridomercury(II)]-µ-1,4-bis[2-(pyridin-4-yl)ethynyl]benzene-κ 2 N:N′]
Crystal data [HgCl 2 (C 20  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  (7)