title: Structure of the hydrated and dimethyl sulfoxide solvated rubidium ions in solution.
abstract: The structure of the hydrated and the dimethyl sulfoxide solvated rubidium ions in solution has been determined by means of large-angle X-ray scattering (LAXS) and extended X-ray absorption fine structure (EXAFS) studies. The models of the hydrated and dimethyl sulfoxide solvated rubidium ions fitting the experimental data best are square antiprisms with Rb-O bond distances of 2.98(2) and 2.98(3) A, respectively. The EXAFS data show a significant asymmetry in the Rb-O bond distance distribution with C(3) values of 0.0076 and 0.015 A(3), respectively. No second hydration sphere is observed around the hydrated rubidium ion. The dimethyl sulfoxide solvated rubidium ion displays a Rb-O-S bond angle of ca. 130 degrees, which is typical for a medium hard electron acceptor such as rubidium.
authors.affiliation: Dipartimento di Chimica, Università di Roma La Sapienza, Piazzale Aldo Moro 5, I-00185 Rome, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: D'Angelo
authors.forename: Ingmar
authors.initials: I
authors.lastname: Persson
mesh_terms: D002412:Cations; D004121:Dimethyl Sulfoxide / Q000737:chemistry*; D004583:Electrons; D008698:Mesylates / Q000737:chemistry; D015394:Molecular Structure; D010100:Oxygen / Q000737:chemistry; D012413:Rubidium / Q000737:chemistry*; D012542:Scattering, Radiation; D012996:Solutions; D013052:Spectrometry, X-Ray Emission; D014867:Water / Q000737:chemistry*
chemical_list: D002412:Cations; D008698:Mesylates; D012996:Solutions; D014867:Water; C012077:trifluoromethanesulfonic acid; D012413:Rubidium; D010100:Oxygen; D004121:Dimethyl Sulfoxide