Using ionic liquids to trap unique coordination environments: polymorphic solvates of ErCl3(OH2)(4).2([C2mim]Cl).

Two polymorphs of ErCl(3)(OH(2))(4).2([C(2)mim]Cl) solvates were isolated from the same solution of 1-ethyl-3-methylimidazolium chloride when HCl(aq) was added, while [C(2)mim](3)[ErCl(6)] was isolated without HCl addition, illustrating how ionic liquids can be used to trap unusual coordination environments in the solid state.

Interactions of 1-methylimidazole with UO2(CH3CO2)2 and UO2(NO3)2: structural, spectroscopic, and theoretical evidence for imidazole binding to the uranyl ion.

The first definitive high-resolution single-crystal X-ray structure for the coordination of the 1-methylimidazole (Meimid) ligand to UO2(Ac)2 (Ac = CH3CO2) is reported. The crystal structure evidence is confirmed by IR, Raman, and UV-vis spectroscopic data. Direct participation of the nitrogen atom of the Meimid ligand in binding to the uranium center is confirmed.

Identical extraction behavior and coordination of trivalent or hexavalent f-element cations using ionic liquid and molecular solvents.

The extraction of both UO2(2+) and trivalent lanthanide and actinide ions (Am3+, Nd3+, Eu3+) by dialkylphosphoric or dialkylphosphinic acids from aqueous solutions into the ionic liquid, 1-decyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide has been studied and compared to extractions into dodecane. Radiotracer partitioning measurements show comparable patterns of distribution ratios for both the ionic liquid/aqueous and dodecane/aqueous systems, and the limiting slopes at low acidity indicate the partitioning of neutral complexes in both solvent systems. The metal ion coordination environment, elucidated from EXAFS and UV-visible spectroscopy measurements, is equivalent in the ionic liquid and dodecane solutions with coordination of the uranyl cation by two hydrogen-bonded extractant dimers, and of the trivalent cations by three extractant dimers.