(μ2-2-Methoxyethanol-κ3 O 1:O 1,O 3)(2-methoxyethanol-κO 1)tris(μ2-3,4,5,6-tetrafluoro-o-phenylene-κ2 C 1:C 2)trimercury(II)

In the title compound, [Hg3(C6F4)3(C3H8O2)2], two O atoms from one 2-methoxyethanol ligand and one O atom from the second 2-methoxyethanol ligand coordinate three HgII atoms [Hg—O = 2.765 (7)–2.890 (8) Å] in the trimeric organomercurial Lewis acid (o-C6F4Hg)3. The hydroxy groups are involved in formation of intra- and intermolecular O—H⋯O hydrogen bonds; the latter link two molecules into centrosymmetric dimers. An extensive net of weak intermolecular C—H⋯F interactions further consolidates the crystal packing.

In the title compound, [Hg 3 (C 6 F 4 ) 3 (C 3 H 8 O 2 ) 2 ], two O atoms from one 2-methoxyethanol ligand and one O atom from the second 2-methoxyethanol ligand coordinate three Hg II atoms [Hg-O = 2.765 (7)-2.890 (8) Å ] in the trimeric organomercurial Lewis acid (o-C 6 F 4 Hg) 3 . The hydroxy groups are involved in formation of intra-and intermolecular O-HÁ Á ÁO hydrogen bonds; the latter link two molecules into centrosymmetric dimers. An extensive net of weak intermolecular C-HÁ Á ÁF interactions further consolidates the crystal packing.

Comments
As an organomercurial compound trimeric perfluoro-o-phenylene mercury (I) has numerous adducts with aldehydes, ketones, amides, nitriles, phosphoramides, and sulfoxides (Taylor et al., 2007). Formation of complexes involving I with oxygenated Lewis bases similar to 2-methoxyethanol (II) had been observed before (Tikhonova et al., 2002). The studies of this type of coordination are important due the effect of I on the keto-enol tautomerism (Tikhonova et al., 2013) as well on the activation of carbonyl compounds (Tikhonova et al., 2002). Acting as Lewis acid I had proven catalyze the Diels-Alder reaction between thionoester and cyclopentadiene (Lee et al., 1999). Besides II is not a strong Lewis base it exhibits shorter Hg···O contacts than the sum of the van der Walls radii (Hg = 1.7-2 Å, O = 1.52 Å).
In the title compound ( Fig. 1), the coordinating Hg···O contacts range from 2.765 (7) to 2.890 (8) Å. These short contacts are in the same range as those described for carbonyl compounds (Tikhonova et al., 2002). The present complex [I·(II) 2 ] has two II molecules per one I molecule. The hydroxy groups are involved in formation of intra-and intermolecular O-H···O hydrogen bonds (Table 1), and the latter ones link two complex molecules into centrosymmetric dimers. An extensive net of weak intermolecular C-H···F interactions (Table 1) consolidate further the crystal packing.
To the best of our knowledge this complex is the first coordination example of a non-cyclic ether with macrocycle I. That indicates a possibility of I to form complexes with non-cyclic ethers, like polyethylene glycol derivatives.

Synthesis and crystallization
Trimeric perfluoro-o-phenylene mercury (I) was synthesized according to the known procedure (Sartori & Golloch, 1968). The title compound [I·(II) 2 ] was obtained by dissolving pure I in II, followed by slow evaporation of the solvent until single crystals were obtained.

Refinement
All hydrogen atoms were placed in the calculated positions with O-H = 0.84 Å, C-H = 0.98-0.99 Å and refined as riding, with U iso (H) = 1.2-1.5 U eq of the parent atom.  The molecular structure of the title compound showing the atomic numbering and 50% probability displacement ellipsoids. Dashed line denotes hydrogen bond.