REACTIONS OF AZACORONANDS WITH MERCURY(II ) IODIDE - CRYSTAL-STRUCTURES OF 2 COMPLEXES OF HGI2 WITH DIAZA-15-CROWN-5, AND DIAZA-18-CROWN-6

The reactions of diaza-15-crown-5 (''2.1''), and diaza-18-crown-6 (''2 .2''), resp., with HgI2 in methanol afford the compounds [Hg(2.1)I][Hg 2I6] (1) and [Hg(2.2)I][Hg2I6] (2), the crystal structures of which we re determined. 1 consists of isolated cations [Hg(2.1)I](+) and anions [Hg2I6](2-). In the cations Hg is coordinated by one iodine atom, the two N atoms and the three O atoms of the ligand; the Hg-I distance is 262.1(3) pm, the Hg-N bond lengths are 221(2) and 238(2) pm; they are significantly shorter than the Hg-O distances, which are in the range between 262 and 271 pm. 2 consists of cations [Hg(2.2)I](+), which ar e bridged by the anions. In the cations of 2 Hg is coordinated by an i odine atom and by the two N atoms of the ligand, but by only three of the four O atoms. The Hg-I distance is 275.8(5) pm, the mean Hg-N bond length 234(4) pm, and the Hg-O distances vary between 285 and 304 pm. The Hg-I distance to the bridging I atom of the anion is 388.6(6) pm. The Hg-I bond lengths within the anions are slightly widened by this coordination.