Details

Autor(en) / Beteiligte

• Kravchuk, Dmytro V.
• Wilson, Richard E.

Titel

Synthesis and characterization of the rare-earth chloride complexes with N,N,N′,N′-tetramethylmalonamide

Ist Teil von

• Journal of solid state chemistry, 2024-04, Vol.332, p.124595, Article 124595

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2024

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• Exploration of the solid-state chemistry of the f-elements and their coordination chemistry can assist in understanding the speciation of these elements in solution, which, in turn, can aid in the interpretation of their chemical behavior in complex liquid-liquid separations. Within these separation processes, malonamides are common organic extractants that are used for complexing both lanthanides and actinides, thus it is relevant to understand the malonamide ligand complexation under various conditions. In this work, we investigate solid-state complexes of the rare-earth chlorides with N,N,N′,N′-tetramethylmalonamide (TMMA) across the entire lanthanide series. We isolated two structural families of compounds Ln(TMMA)2Cl3 Ln = La–Dy and [Ln(TMMA)2(H2O)4]Cl3 • xH2O x = 0,4 Ln = Ho–Lu, showing differences in chloride coordination from the inner-sphere complex for early lanthanides to outer-sphere for the late lanthanides. Both structural series were additionally analyzed by both IR and Raman spectroscopy confirming similarities in malonamide ligand coordination modes, while showing differences in vibrational features associated with chloride and aqua ligand coordination. Solid-state complexes with N,N,N′,N'-tetramethylmalonamide have been isolated across the entire row of the rare-earth metals out of the chloride media. Based on crystallographic results, early and middle lanthanides (La–Dy) are prone to bind two malonamides along with three chloro ligands in the inner coordination sphere. The complexes of the late lanthanides (Ho–Lu) show an exchange of chloro ligands to aqua ligands due to more favorable hydration enthalpies of the metal cation. Complimentary IR and Raman spectra confirm the coordination of the diamide ligands and demonstrate the chloro ligand exchange moving across the rare-earth series. [Display omitted] •Solid-state compounds with malonamide ligands have been isolated across the entire lanthanide series.•Crystallographic investigation of the entire compound series was performed and compared to their nitrate counterparts.•Compounds were analyzed using both IR and Raman spectroscopy to confirm the ligand binding motifs