Solvation structure and bromo complexation of neodymium(III) and yttrium(III) ions in solvent mixtures of N,N-dimethylformamide and N,N-dimethylacetamide

X-ray Absorption Spectroscopy (XAS) Study of the Hydration Structure of Yttrium(III) Cations in Liquid and Glassy States: Eight or Nine-Fold Coordination?

“…38 The existence of inner-sphere complexes involving Branion was first postulated for concentrated solutions of ErBr 3 using X-ray diffraction. 39 Recently, direct evidence of this sort of complex was obtained by EXAFS in solutions of thulium(III) 40 and yttrium(III) 41 bromide in dimethylformamide (DMF)-dimethylacetamide (DMA) mixtures, and by using NMR in YBr 3 solutions in the same type of solvents. 42 Moreover we have not found evidence of the presence of solvent-separated Y 3+ -Brion pairs in either in the liquid state or in the glassy system.…”

Solvation structure of lanthanide(iii) ions in solvent mixtures of N,N-dimethylformamide and N,N-dimethylacetamide studied by titration Raman spectroscopyElectronic supplementary information (ESI) available: Crystallographic data (single crystal, [Gd(DMF)4(DMA)4](ClO4)3), (CCDC reference number 185878). See http://www.rsc.org/suppdata/cp/b2/b204162f/

“…3+ solvate in the range x DMA > 0.4 may play a key role in the outer-to innersphere transition of the bromo complexes in the DMF-DMA mixture. Indeed, as described in the Introduction, the lanthanide(III) ion forms an outer-sphere LnBr 2+ complex in DMF and an inner-sphere complex in DMA, 6 and the bromide ion penetrates into the solvation shell of the metal ion at x DMA > 0.4 in the solvent mixture, where the Ln(DMA) 4 (DMF) nÀ1 3+ solvate ion is formed.…”

“…The bromide ion thus penetrates into the solvation shell of the metal ion at a given solvent composition in the DMF-DMA mixture. Interestingly, the solvent composition above which the contact LnBr 2+ ion-pair forms is about 0.4 mole fraction of DMA, independent of the metal ions, 6 despite the fact that the ionic size of the lanthanide(III) ions is significantly different. 7 According to our previous results from an extended X-ray absorption fine structure (EXAFS), 8 all lanthanide(III) ions are mainly eight-coordinated in DMF, while seven-and eight-coordinated species coexist in equilibrium in DMA, and the equilibrium shifts strongly toward seven for heavy lanthanides.…”

Structure of the solvated yttrium(III) ion in the oxygen donor solvents dimethyl sulfoxide, N,N-dimethylformamide and N,N′-dimethylpropyleneurea and crystal structures of [Y(OSMe2)8]I3 and [Y(OCN2Me2(CH2)3)6]I3

“…Few structural investigations have been made of the solvated yttrium() ion in non-aqueous solution. 1 Previous large angle X-ray scattering (LAXS) studies of yttrium() nitrate and chloride in dimethyl sulfoxide solutions indicated a coordination number of eight, but with inner-sphere complex formation of the anions. 2 Owing to the similarity in size and chemical behaviour, the structural chemistry of yttrium() is often compared with that of the heavy lanthanide() ions.…”