Recovery of platinum group metals from spent materials is becoming increasingly relevant due to the high value of these metals and their progressive depletion. In recent years, there is an increased interest in developing alternative and more environmentally benign processes for the recovery of platinum group metals, in line with the increased focus on a sustainable future. To this end, ionic liquids are increasingly investigated as promising candidates that can replace state-of-the-art approaches.
View Article and Find Full Text PDFWe studied the extraction behavior of two thioglycolate-based ionic liquids (ILs), for heavy metals from aqueous solutions; substances of interest were methyltrioctylammonium S-hexyl thioglycolate [N][CSAc] and methyltrioctylphosphonium S-hexyl thioglycolate [P][CSAc]. Theses ILs previously have shown very good extraction abilities towards cadmium and copper, therefore we investigated time-dependent metal removal experiments with aqueous solutions of cobalt(II), nickel(II) and zinc(II). The highest distribution ratio (R) was determined for zinc (R=2000).
View Article and Find Full Text PDFEight novel task-specific ionic liquids (TSILs) based on the thioglycolate anion designed for heavy metal extraction have been prepared and characterized by H and C NMR, UV-Vis, infrared, ESI-MS, conductivity, viscosity, density and thermal properties. Evaluation of their time-resolved extraction abilities towards cadmium(II) and copper(II) in aqueous solutions have been investigated where distribution ratios up to 1200 were observed. For elucidation of the IL extraction mode, crystals were grown where Cd(II) was converted with an excess of S-butyl thioglycolate.
View Article and Find Full Text PDFTwo water-soluble thiosemicarbazone-proline (H2L(1)) and thiosemicarbazone-homoproline hybrids (H2L(2)) were synthesised. By reaction of H2L(1) with NiCl2·6H2O, PdCl2 and CuCl2·2H2O in ethanol, the series of square-planar complexes [Ni(H2L(1))Cl]Cl·1.3H2O (1·1.
View Article and Find Full Text PDFThis study aims to develop novel ammonium and phosphonium ionic liquids (ILs) with thiosalicylate (TS) derivatives as anions and evaluate their extracting efficiencies towards heavy metals in aqueous solutions. Six ILs were synthesized, characterized, and investigated for their extracting efficacies for cadmium, copper, and zinc. Liquid-liquid extractions of Cu, Zn, or Cd with ILs after 1-24h using model solutions (pH 7; 0.
View Article and Find Full Text PDFTwo novel maltol-based ionic liquids, namely [A336][Mal] and [C101][Mal], were synthesized as potential extracting agents for radionuclides from water. These two room temperature task-specific ionic liquids could be easily prepared by anion metathesis starting from commercially available materials. The isolated compounds were characterized by standard analytical methods.
View Article and Find Full Text PDFReactions of 5-tert-butyl-2-hydroxy-3-methylsulfanylbenzaldehyde S-methylisothiosemicarbazone and 5-tert-butyl-2-hydroxy-3-phenylsulfanylbenzaldehyde S-methylisothiosemicarbazone with pentane-2,4-dione (Hacac) and triethyl orthoformate in the presence of M(acac)2 as template source at 107 °C afforded metal complexes of the type M(II)L(1) and M(II)L(2), where M = Ni and Cu, with a new Schiff base ligand with thiomethyl (H2L(1)) and/or thiophenyl (H2L(2)) group in the ortho position of the phenolic moiety. Demetalation of NiL(1) in CHCl3 with HCl(g) afforded H2L(1). The latter reacts with Zn(OAc)2·2H2O with formation of ZnL(1).
View Article and Find Full Text PDF