Synthesis and structure of an aryl-tellurenium(II) cation; [4- tert -butyl-2,6-bis-(1-pentyl-1 H -benz-imidazol-2-yl-κ N 3 )phenyl-κ C 1 ]tellurium(II) (1,4-dioxane)tri-iodido-mercurate(II).

In the title salt, (C34 H41 N4 Te)[HgI3 (C4 H8 O2 )], the aryl-tellurenium [C34 H41 N4 Te]+ cations and [HgI3 (dioxane)]- anions are linked by a short inter-action between the Te atom and one of the I-atom donors of the anion, as well as through weak C-H⋯I inter-actions. The geometry around the Te atom is T-shaped with the coordination comprising a C atom of the central aromatic ring and two N atom donors of the benzimidazolyl moiety. The Te-N bond lengths are almost equal [2.232 (3) and 2.244 (3) Å], while the Te-C bond length is 2.071 (4) Å. The N-Te-N bond angle is 150.68 (11)°. The HgII atom of the anion is coordinated by iodide ions from three sides and the fourth coordination site is occupied by an O atom of the solvent mol-ecule (dioxane). Thus, it attains a trigonal-pyrimidal geometry, with O-Hg-I angles ranging of 90.76 (8) and 96.76 (7)° and I-Hg-I angles ranging from 112.41 (1) to 125.10 (1)°. The cations and anions are involved in numerous weak π-π stacking inter-actions involving both the central phenyl ring and two inversion-related benzimidazole moieties, which propagate in the a -axis direction. In addition, there are numerous C-H⋯I inter-actions between the cations and anions, which link them into a complex three-dimensional array.