On the coordination chemistry of the dimercury(I) ion with O-donor ligands

• An overview of published crystalline dimercury(I) hydrates, solvates, and complexes/compounds with other O-donor ligands shows that there is virtually no correlation between the Hg-Hg bond distance and the overall Hg-O bonding conditions. Additionally, many structures feature a different Hg-O bonding situation for the different halves of the dimercury(I) ion, Hg22+. To supplement these findings, the crystal structures of the perchlorate salts of hydrated and dimethylsulfoxide (dmso) solvated mercury(I), [Hg2(H2O)2](ClO4)2 (1) and [Hg10(OS(CH3)2)16](ClO4)10 (2), respectively, have been determined by single crystal X-ray diffraction. In compound 1, the perchlorate ions act as bridges between the almost linear [Hg2(H2O)2]2+ units forming infinite chains. The Hg-Hg bond distance is 2.500(1) Å and the Hg-O distance to the water molecule is 2.231(19) Å, and with six additional much weaker Hg-O bonds to bridging perchlorate oxygens in the range 2.78-3.15 Å. Compound 2 consists of five separate entities where the [Hg-Hg]2+ units are solvated and bridged by dmso oxygens. These entities form chains through much weaker bridging perchlorate ions at longer distances, 3.0-3.3 Å, with a few remaining perchlorate ions isolated in the lattice. The mean Hg-Hg bond distance is 2.500(1) Å, while the Hg-Odmso bond distances are in the range of 2.15-2.92 Å. The dmso molecules display three kinds of coordination, strong κO-terminal, medium μ2O-bridging, or medium + weak μ3O-bridging, depending on which mercury(I) ion(s) in the entity they coordinate to.

Subject headings

NATURVETENSKAP  -- Kemi -- Oorganisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Inorganic Chemistry (hsv//eng)

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ref (subject category)

art (subject category)