An EXAFS Spectroscopic, Large Angle X-Ray Scattering and Crystallo¬graphic Study of the Hexahydrated and the Dimethyl Sulfoxide and Pyridine-1-Oxide Hexasolvated Mercury(II) Ions
2008 (English)In: Chemistry, A European Journal, Vol. 14, 6687-6696 p.Article in journal (Other (popular science, discussion, etc.)) Published
The structure of the solvated mercury(II) ion in aqueous and dimethyl sulfoxide solution has been studied by means of large angle X-ray scattering (LAXS) and EXAFS tech¬niques. The distribution of the Hg-O bond distances is unusually wide and asymmetric in both solvents. In aqueous solution hexahydrated [Hg(OH2)6]2+ ions in distorted octahedral configuration, with the centroid of the Hg-O bond distances at 2.38(1) Å, are surrounded by a diffuse second hydration sphere, with HgOII distances around a mean value of 4.20(2) Å. In dimethyl sulfoxide solution the six Hg-O and HgS distances of the hexasolvated Hg(OS(CH3)2)6]2+ complex are centered around 2.38(1) and 3.45(2) Å, respectively. The crystal structure of hexakis¬(pyridine-1-oxide)mercury(II) perchlorate has been re-determi¬ned at 100 K. The space group R implies six equal Hg-O bond distances of 2.3416(7) Å for the Hg(ONC5H5)62+ complex, as also for the hexaaquamercury(II) perchlorate and hexakis(dimethyl sulfoxide)mercury(II) trifluoro¬methanesulfonate compounds, according to previous crystallographic results. However, EXAFS results for those compounds in all cases reveal strongly asymmetric Hg-O bond distance distributions. Vibronic coupling of close valence states in a so-called Pseudo Jahn-Teller Effect probably induces the distorted configurations.
Place, publisher, year, edition, pages
2008. Vol. 14, 6687-6696 p.
Mercury(II) solvation, EXAFS spectroscopy, X-ray diffraction, solution structure
IdentifiersURN: urn:nbn:se:su:diva-14876ISI: 000258217000016OAI: oai:DiVA.org:su-14876DiVA: diva2:181396