Solvent structure and the extended range hydration of Cr3+ in aqueous solution.
H/D isotopic substitution neutron scattering has been used to investigate the short and intermediate range solution structure in a 1 m aqueous solution of chromium nitrate. To improve the reliability of the local structural information on the cation environment, information has been incorporated from available extended X-ray absorption fine structure (EXAFS) spectroscopy data into the applied analytical framework. The markedly different structural sensitivities of the experimental probes allow the construction of a detailed three-dimensional atomistic model using the empirical potential structure refinement (EPSR) technique. The method facilitates the construction of a model that is consistent with regards to both the structural details of the immediate Cr(3+) aqua-ion environment and the bulk hydrogen-bonded network of solvent water molecules. The results confirm the suitability of the [Cr(H(2)O)(6)](3+) hydrated ion concept to describe the first hydration shell of this cation and clarify how this pseudomolecular unit is structurally incorporated in the longer range aqueous environment.
Bowron
Daniel T
DT
ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, United Kingdom. daniel.bowron@stfc.ac.uk
Díaz-Moreno
Sofia
S