Bis((E)-2-{3-[4-(1H-imidazol-1-yl-κN 3)styryl]-5,5-dimethylcyclohex-2-enylidene}malononitrile)diiodidomercury(II)

In the title compound, [HgI2(C22H20N4)2], the HgII cation is situated on a twofold rotation axis and is coordinated by two iodide anions and two imidazolyl N atoms in a distorted tetrahedral geometry. In the crystal, C—H⋯I interactions link the molecules into chains extending in [010], which are further linked into sheets parallel to (100) through C—H⋯N hydrogen bonding interactions.

In the title compound, [HgI 2 (C 22 H 20 N 4 ) 2 ], the Hg II cation is situated on a twofold rotation axis and is coordinated by two iodide anions and two imidazolyl N atoms in a distorted tetrahedral geometry. In the crystal, C-HÁ Á ÁI interactions link the molecules into chains extending in [010], which are further linked into sheets parallel to (100) through C-HÁ Á ÁN hydrogen bonding interactions.

Related literature
For the crystal structure of the organic ligand of the title compound, see: Zheng et al. (2013). For mercury(II) complexes in which the Hg(II) cation is four-coordinated by two terminal iodide ions and two N atoms from organic ligands in a distorted tetrahedral geometry, see: Li (2011); Shirvan et al. (2012).

Comment
The organic ligand of the title compound has previously been investigated for its optical properties (Zheng et al., 2013).
In addition, some mercury(II) complexes in which the Hg(II) cation is four-coordinated by two terminal iodide ions and two nitrogen atoms from organic ligands to form distorted tetrahedral geometry have been reported (Li, 2011;Shirvan et al., 2012). In this study, we report the crystal structure of the title compound ( Fig. 1). In the molecular packing structure of the compound, intermolecular C-H···I interactions link the molecules into chains. The neighboring chains are further linked into sheets through C-H···N hydrogen bonding interactions (Fig.2). Intermolecular hydrogen bonds lengths and angles are reported in Table.1.

Refinement
All hydrogen atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C -H = 0.93 Å and U iso (H) = 1.2 U eq .  The molecular structure of the title molecule. [Symmetry code: #1: -x + 1,y,-z + 3/2].

Figure 2
Packing diagram of the title compound viewed along b axis. Intermolecular C-H···I and C-H···N interactions are shown as dashed lines in pink and yellow, respectively.

Bis((E)-2-{3-[4-(1H-imidazol-1-yl-κN 3 )styryl]-5,5-dimethylcyclohex-2-enylidene}malononitrile)diiodidomercury(II)
Crystal data 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