Evidence of three-body correlation functions in Rb+ and Sr2+ acetonitrile solutions

Abstract

The local structure of Sr2+ and Rb+ ions in acetonitrile has been investigated by x-ray absorption spectroscopy (XAS) and molecular dynamics simulations. The extended x-ray absorption fine structure above the Sr and Rb K edges has been interpreted in the framework of multiple scattering (MS) formalism and, for the first time, clear evidence of MS contributions has been found in noncomplexing ion solutions. Molecular dynamics has been used to generate the partial pair and triangular distribution functions from which model χ(k) signals have been constructed. The Sr2+ and Rb+ acetonitrile pair distribution functions show very sharp and well-defined first peaks indicating the presence of a well organized first solvation shell. Most of the linear acetonitrile molecules have been found to be distributed like hedgehog spines around the Sr2+ and Rb+ ions. The presence of three-body correlations has been singled out by the existence of well-defined peaks in the triangular configurations. Excellent agreement has been found between the theoretical and experimental data enforcing the reliability of the interatomic potentials used in the simulations. These results demonstrate the ability of the XAS technique in probing the higher-order correlation functions in solution. © 1999 American Institute of Physics

Solution X-ray Absorption Fine Structure Study of the Eu2+and Sr2+Ions: Unexpected Solvent and Metal Ion Dependencies of the Solvation Numbers

“…In the literature, only two references relevant to our study were found. Both of them were XAFS studies, one about Sr 2+ solvation in DMSO 18 and the other about Sr 2+ solvation in MeCN . Results for the Sr 2+ aqua ion by the same authors 18,24 are also reported in Table for comparison.…”

“…The Sr-O distances that we found are very close to those obtained by Persson et al in both aqueous and DMSO solutions (Table 6). D'Angelo et al 36 performed an XAFS analysis on a 0.06 M Sr(O 3 SCF 3 ) 2 in MeCN solution. They fitted the XAFS raw data (without FT) using a cluster based on a classical molecular dynamics simulation.…”

“…D'Angelo et al 36 performed an XAFS analysis on a 0.06 M Sr(O 3 SCF 3 ) 2 in MeCN solution. They fitted the XAFS raw data (without FT) using a cluster based on a classical molecular dynamics simulation.…”

Investigation of undercooled liquid metals using XAFS, temperature scans and diffraction

“…This method has been widely applied by us and by other groups for the EXAFS determinations of liquid structures and the results were always found to be in excellent agreement with other structural determinations, when available for comparison. An extended reference list is reported for the convenience of the reader (Bowron et al, 1998;D'Angelo & Pavel, 1999;D'Angelo et al, 1994;Di Cicco, 1996;Di Cicco et al, 1996De Pan®lis & Filipponi, 1997;Filipponi & Di Cicco, 1995;Filipponi et al, 1997.…”

Advances in modelling X-ray absorption spectroscopy data using reverse Monte Carlo

“…10,11 The application of this methodology has been shown to be successful in describing the short-range pair distribution function of “simple” elemental melts, ionic binary liquids and aqueous solutions (see ref. 10, 12–16 and the review paper 17 ).…”