Bis(1,3-diethylbenzimidazolium) tetrabromidomercurate(II)

In the title compound, (C11H15N2)2[HgBr4], the tetracoordinated HgII center of the complex anion adopts a distorted tetrahedral geometry [Hg—Br = 2.5755 (8)–2.623 (11) Å and Br—Hg—Br = 103.78 (19)–116.4 (3)°]. One of the Br atoms is disordered over two sites [site-occupancy factors = 0.51 (6) and 0.49 (6)]. The N—C—N angles in the cations are 110.7 (6) and 111.4 (7)°. In the crystal packing, a supramolecular chain is formed via both weak intermolecular C—H⋯Br hydrogen bonds and π–π aromatic ring stacking interactions [centroid–centroid separation = 3.803 (1) Å].


S3. Refinement
All H atoms were initially located in a difference Fourier map. These were then placed in geometrically idealized positions and constrained to ride on their parent atoms, with Csp 3 -H = 0.97 Å,Csp 2 -H = 0.93 Å and U iso (H) = 1.2U eq (C). One of the bromide atoms was found to be disordered over two close sites: Br1/ Br1′ [occupancy factors 0.49 (6)/0.51 (6)]. One reflection was considered to be affected by the beamstop.  Atom naming scheme for the title compound (I), with displacement ellipsoids drawn at the 30% probability level. All H atoms have been omitted.

Figure 2
The one-dimensional supramolecular chain of the title compound formed via C-H···Br hydrogen bonds and π-π interactions. The non-interactive H atoms have been omitted.

Figure 3
The formation of the title compound.

Bis(1,3-diethylbenzimidazolium) tetrabromidomercurate(II)
Crystal data (C 11  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 Occ. (