Stability of europium(ii) in aqueous nitrate solutions

Abstract

Investigation of the reduction of Eu3+ and the stability of Eu2+ in aqueous solutions containing high nitrate salt concentrations.

Electrochemical and Spectroscopic Study of EuIII and EuII Coordination in the 1‐Ethyl‐3‐methylimidazolium Bis(trifluoromethylsulfonyl)imide Ionic Liquid

“…[10] For instance, lanthanide (Ln) elements are usually found at an oxidation state of + III in aqueouss olution, and oxidation states + II (Eu, Sm, Yb) or + IV (Ce, Pr,T b) require complexation to remain stable in aqueous solution. [11] In contrast,I Lw ere shownt ob eg ood solvents for the stabilization and study of the oxidation states + II and + IV for Ln. [12][13][14][15] Specifically,E u II can be stabilized in aqueous solutions thanks to cyclic ligands such as cryptands or analogues [16] whereasi nn onaqueousm edia, fully dissolved stablef orms of Ln II can be observed.…”

“…Some species that are otherwise difficult to isolate in aqueous solutions can be stabilized in IL [10] . For instance, lanthanide (Ln) elements are usually found at an oxidation state of +III in aqueous solution, and oxidation states +II (Eu, Sm, Yb) or +IV (Ce, Pr, Tb) require complexation to remain stable in aqueous solution [11] . In contrast, IL were shown to be good solvents for the stabilization and study of the oxidation states +II and +IV for Ln [12–15] .…”

Co‐Assembly of Biosynthetic Chiral Nematic Adhesive Materials with Dynamic Polarized Luminescence

“…Transparent Eu‐doping ink was prepared by mixing Eu(III) chloride hexahydrate with KHP at 10:1 weight ratio in deionized water (19 wt% concentration of final solution, see Experimental Section in Supporting Information). [ 59 ] Fine droplets of the Eu solution were deposited on the CNC–PAA film through the piezoelectric ink‐jet nozzle (see Experimental Section in Supporting Information). [ 60–62 ]…”

Ultra-Efficient Americium/Lanthanide Separation through Oxidation State Control

“…While separation of Am from nuclear waste is critical for nuclear waste minimization and is a prerequisite for transmutation in an advanced nuclear fuel cycle, this process poses a significant challenge because Am has similar chemical properties to Ln and the coexistence of an excessive amount of Ln that possesses high neutron cross sections can disrupt the transmutation efficiency of Am. Despite the existence of Ln­(II) and Ln­(IV) in the condensed phase − and Pr­(V) in the gas phase, , both Am and Ln have a strong thermodynamic preference for oxidation state III and their ions are of comparable size. Accordingly, they behave with great chemical similarity under typical conditions, leaving few options for separation. , Therefore, separation of Am from Ln has become a significant challenge in advanced nuclear fuel cycles over the past decades. − One approach often exploited is to take advantage of the slightly less contracted f-orbitals in Am­(III) than in Ln­(III), which endows Am­(III) with preference in miniscule covalent bonding with ligands bearing relatively soft donor atoms such as N and S. ,− However, this approach usually encounters drawbacks such as slow separation kinetics, instability of ligands, and narrow operational acidity, thus hampering its use in industrial applications. , …”