HgO 7 S 2 , monoclinic, P2 1 /n (no. 14), a = 5.1467 ( Hg[S 2 O 7 ] has been prepared in the reaction of 50 mg HgO with 1 mL Oleum (65 % SO 3 ). The reaction was performed in a thickwalled glass ampoule. The tube was loaded with the reactants, torch-sealed under vacuum and placed in a resistance furnace. The ampoule was held at a temperature of 250°C for 24 h and cooled down to room temperature at a rate of 1.8°C·h -1 , leading to a large number of colourless single crystals.
Source of material
Experimental detailsThe structure could be successfully solved using Direct Methods of SHELXS [1]. The structure was expanded using Fourier techniques. Refinement of the structure with anisotropic displacement parameters for all atoms was performed after the data were corrected for absorption effects. All calculations were performed with the SHELX program [1] and the data were processed with the programs X-RED [2] and X-Shape [3].
DiscussionOne of the main research projects of our working group is the investigation of the reactivity of sulfuric acid and its derivatives under harsh conditions. Milestones of this research were the preparation of gold (II) ] crystallizes in the monoclinic space group P2 1 /n with 4 formula units per unit cell. The mercury cations and disulfate anions form 8-, 10-, and 12-membered rings. This leads to a complex three dimensional network for the structure (Fig. top). The complex disulfate anion shows staggered conformation with an O-S-S-O torsion angle of about 52°. The terminal S-O bond lengths range from 144.6(3) to 145.8(3) pm. The bridging S-O-S bonds are nearly symmetric with a S-O bond length of 161.8(3) and 162.5(3) pm. These values are in line with literature data observed for disulfates. The Hg 2+ cation is in octahedral coordination of six oxygen atoms with Hg-O distances ranging from 226.3(2) to 239.3(3) pm and O-Hg-O angles ranging from 82.62°to 98.14° (Fig. bottom), which is much more regular than the observed values in Hg 2 (SO 4 ) [14] and Hg(SO 4 ) [15].