Catalysis by water-soluble phosphine complexes of transition metal ions in aqueous and two-phase media

Detection of biologically important transition metal ions such as copper by using a simple method is desirable and of great importance. In this work, we firstly reported that water-soluble thiacalix[4]arene tetrasulfonate (TCAS) exhibited selective chromogenic recognition towards copper(II) ion over other transition metal ions. Color change from colorless to salmon pink was observed in TCAS solution, weak bathochromic shift was induced in UV absorption spectrum of TCAS upon addition of copper(II) ion, and the absorbance of characteristic absorption band at 312 nm increased linearly with copper(II) ion concentration. The recognition mechanism of TCAS to copper(II) ion was investigated by a comparative study with calix[4]arene tetrasulfonate (CAS) and time-dependent density functional theory(TD-DFT) study, and the absorption bands were assigned based on transition orbital analysis.

Download Full-text

Application of ionic liquid based on Aliquat 336 and D2EHPA in the extraction of transition metals

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1212/1/012021 ◽

2022 ◽

Vol 1212 (1) ◽

pp. 012021

Author(s):

M I Fedorova ◽

A V Levina

Keyword(s):

Ionic Liquid ◽

Transition Metal ◽

Metal Ions ◽

Transition Metal Ions ◽

Liquid Extraction ◽

Phase System ◽

Aliquat 336 ◽

Polypropylene Glycol ◽

Two Phase ◽

Liquid Liquid Extraction

Abstract To date, there are a number of methods for selective extraction of transition metal ions based on liquid-liquid extraction. One of the most interesting methods of metal ions extraction is liquid-liquid extraction with application of ionic liquids based on quaternary ammonium bases and organic acid residues, in particular, organophosphorus, diluted with organic solvent (toluene, xylene, kerosene, etc.). However, using of organic solvents does not correspond to the modern tendencies of harmful effects on the environment reducing. Thus, we propose to use Aliquat 336 and D2EHPA-based ionic liquid for extraction of transition metal ions in ecologically safe aqueous two-phase system based on polypropylene glycol 425 and sodium chloride. Di(2-ethylhexyl) phosphate trioctylmethylammonium has been shown to yield more than 80% Fe(III) and Y(III) ions.

Download Full-text

HREM Study of electron-induced surface radiation damage in ReO3

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087495 ◽

1991 ◽

Vol 49 ◽

pp. 636-637

Author(s):

R. Ai ◽

H.-J. Fan ◽

L. D. Marks

Keyword(s):

Transition Metal ◽

Metal Ions ◽

Metal Oxides ◽

Electron Irradiation ◽

Transition Metal Oxides ◽

Carbon Film ◽

Transition Metal Ions ◽

Surface Radiation ◽

Valence Transition ◽

Electron Microscopes

It has been known for a long time that electron irradiation induces damage in maximal valence transition metal oxides such as TiO2, V2O5, and WO3, of which transition metal ions have an empty d-shell. This type of damage is excited by electronic transition and can be explained by the Knoteck-Feibelman mechanism (K-F mechanism). Although the K-F mechanism predicts that no damage should occur in transition metal oxides of which the transition metal ions have a partially filled d-shell, namely submaximal valence transition metal oxides, our recent study on ReO3 shows that submaximal valence transition metal oxides undergo damage during electron irradiation.ReO3 has a nearly cubic structure and contains a single unit in its cell: a = 3.73 Å, and α = 89°34'. TEM specimens were prepared by depositing dry powders onto a holey carbon film supported on a copper grid. Specimens were examined in Hitachi H-9000 and UHV H-9000 electron microscopes both operated at 300 keV accelerating voltage. The electron beam flux was maintained at about 10 A/cm2 during the observation.

Download Full-text