On the solvation of the mercury(I) ion. A structural, vibration spectroscopic and quantum chemical study

The structure of the solvated mercury(I) ion in solvents such as water, methanol, dimethylsulfoxide, N,N'-dimethylpropyleneurea, acetonitrile and pyridine solution has been studied by means of EXAFS and/or large angle X-ray scattering (LAXS). Raman spectroscopy has been used for the determination of the Hg-Hg stretching frequencies. The Hg-Hg bond length increases with increasing solvating ability of the solvent, while the stretching frequency appears to be almost invariant. The results of quantum chemical calculations indicate a significant influence on the Hg-Hg bond from solvation. The structure of solid anhydrous mercury(l) trifluoromethanesulfonate, Hg-2(CF3SO3)(2) (1), has been determined by powder diffraction methods. The structure comprises of discrete molecules, where each mercury binds to an oxygen atom in the anion, forming an almost linear O-Hg-Hg-O entity; the Hg-Hg-O angle is 173degrees and the Hg-Hg and Hg-O bond lengths are 2.486(6) and 2.099(22) Angstrom, respectively. (C) 2004 Elsevier B.V. All rights reserved.