[1,3-Bis(2-ethoxyphenyl)triazenido]bromidomercury(II)

To the central atom of the title compound, [HgBr(C16H18N3O2)], is attached one bromide ion and a 1,3-bis(2-ethoxyphenyl)triazenide ligand through one O and two N atoms, forming a distorted square-planar geometry around the HgII atom. The mononuclear complexes are linked into centrosymmetric dimers by non-classical intermolecular C—H⋯N hydrogen bonds and by weak Hg–η3-arene π-interactions [mean distance = 3.434 (3) Å]. The resulting dimeric units are assembled into zigzag chains by translation along the crystallographic c axis through secondary C—H⋯π edge-to-face benzene ring interactions.

To the central atom of the title compound, [HgBr(C 16 H 18 N 3 O 2 )], is attached one bromide ion and a 1,3bis(2-ethoxyphenyl)triazenide ligand through one O and two N atoms, forming a distorted square-planar geometry around the Hg II atom. The mononuclear complexes are linked into centrosymmetric dimers by non-classical intermolecular C-HÁ Á ÁN hydrogen bonds and by weak Hg-3 -arene -interactions [mean distance = 3.434 (3) Å ]. The resulting dimeric units are assembled into zigzag chains by translation along the crystallographic c axis through secondary C-HÁ Á Á edge-toface benzene ring interactions.
It is isomorphous to the latter chloride complex.
supplementary materials sup-2 The sum of the weak non-covalent interactions seems to play an important role in the crystal packing. The unit cell packing diagram of the title compound is shown in Fig. 4.

Experimental
A methanol solution of 1,3-bis(2-ethoxyphenyl)triazene (0.2853 g, 1 mmol) was added to a methanol solution of mercury(II) bromide (0.3604 g, 1 mmol). After mixing for 1 h at room temperature, an orange solid was readily precipitated out. It was then filtered off, washed with methanol and dried in vacuum. The orange crude material was dissolved in 10 ml of THF, and placed in a freezer without covering. After two weeks beautiful orange and air-stable crystals of the title complex were obtained by slow evaporation of the solvent.

Refinement
Positions of the H(C) were calculated from geometry with C-H = 0.95 -0.99 Å. All hydrogen atoms were refined by use of a riding model with U iso (H) parameters equal to 1.5 U eq (C) for methyl groups and to 1.2 U eq (C) for other carbon atoms where U eq (C) are the equivalent isotropic thermal parameters of the atoms to which the corresponding H atoms are bonded. Fig. 1. Molecular structure of the title compound, with ellipsoids drawn at the 50% probability level. Fig. 2. Non-classical C13-H13B···N2 hydrogen bond with H13B···N2 distance of 2.60 Å and weak Hg-η 3 -arene π-interactions (mean distance of 3.434 (3) Å) between dimers. The secondary Hg-η 3 -arene π-interactions involve three carbon atoms of the C1-C6 phenyl ring.