Hexahalometallate salts of trivalent scandium, yttrium and lanthanum: cation–anion association in the solid state and in solution

Abstract

The hydrogen bonding of hexahalometallate anions with various organic cations is explored via crystallographic and solution NMR studies.

Effect of the cation structure on the properties of homobaric imidazolium ionic liquids

“…Heavier elements such as Br are significantly larger than 2p elements and this must be accounted for when classifying the strength of hydrogen bonding. 68,69 A pertinent example is the OHÁ Á ÁBr bond in [HOC 2 C 1 im]Br involving the alcohol group on the cation and the bromide anion (Table 4). This bond is almost linear but the O-Br distance is B0.73 Å longer than the strict cut-off for a strong hydrogen bond.…”

Electrochemical Approaches for the Recovery of Metals from Electronic Waste: A Critical Review

“…HFCs are however more useful for SCFED media thanks to their accessible critical conditions, more polar nature, and higher dielectric constant, so that the addition of a polar co-solvent is not necessarily needed [110]. Champion et al synthesized some hexahalide salts that incorporated trivalent metal ions from group 3 as well as lanthanides and showed their enhanced dissociation in HFCs solvents [118] [119]. Bartlett et al reported a common approach to the SCFED for a range of p-block elements from supercritical CH 2 F 2 in the presence of tetrabutylammonium chloride as the electrolyte [120].…”

Crystallographic Insights into the Behavior of Highly Acidic Metal Cations in Ionic Liquids from Reactions of Titanium Tetrachloride with [1-Butyl-3-Methylimidazolium][X] Ionic Liquids (X = Chloride, Bromide, Tetrafluoroborate)

“…Many such structures are reported for divalent metal ions including Cr, 8 Cu, 9,10,11,12 Co, 11,13,14 Fe, 11,15 Ge, 16 Hg, 17 Mn, 11 Ni, 11,13 Pb, 18 Pd 9, 19 , 20 , 21 , Pt, 11 Sn, 11,22 and Zn. 11,23 In addition to the well-studied [AlCl4]systems, 24 crystal structures are known for chlorometallates of trivalent Au, 25,26 Bi, 27 Ce, 28,29 Dy, 30 Er, 30,31 Eu, 30,32 Fe, 33,34,35 Gd, 32 La, 36,37 Nd, 32 Pr, 32 Sb, 38 Sc, 29 Sm, 32, Y, 29 and Yb. 30 However, for tetravalent metal ions, the list is restricted to just Ge, 16 Ir, 25 Pt, 25 Sn,…”

“…This is especially clear if one looks at the published crystal structures of 1,3-dialkylimidazolium chlorometallates, an especially well-investigated subset of halometallate ILs. Many such structures are reported for divalent metal ions including Cr, Cu, − Co, ,, Fe, , Ge, Hg, Mn, Ni, , Pb, Pd, ,− Pt, Sn, , and Zn. , In addition to the well-studied [AlCl 4 ] − systems, crystal structures are known for chlorometallates of trivalent Au, , Bi, Ce, , Dy, Er, , Eu, , Fe, − Gd, La, , Nd, Pr, Sb, Sc, Sm, , Y, and Yb . However, for tetravalent metal ions, the list is restricted to just Ge, Ir, Pt, Sn, Ti, − U, V, and Zr, ,,− for pentavalent ions only Np, and Nb, , and for hexavalent ions only U and Mo. , This may reflect how the weakly coordinating ions found in many commonly used ILs cannot dissolve salts of highly charged ions.…”