Thermomorphic metal scavengers: A synthetic and multinuclear NMR study of highly fluorinated ketones and their application in heavy metal removal

Modulating extraction and retention of fluorinated β-diketonate metal complexes in perfluorocarbons through the use of non-fluorinated neutral ligands

Extraction of metal ions into perfluorocarbon solvent with a fluorinated acac ligand is described as well as synergistic extraction with neutral nitrogen donor ligands. Applications include catalysis, nuclear fuels reprocessing, and medical imaging.

Functionalized Polyisobutylene and Liquid/Liquid Separations as a Method for Scavenging Transition Metals from Homogeneously Catalyzed Reactions

Ethanedithiol-functionalized polyisobutylene was prepared in one step by a photoinitiated thiol-ene “click” reaction starting from ethanedithiol and polyisobutylene (PIB). The functionalized oligomer product was then used as a soluble sequestrant for transition metals. This PIB-bound thioether-thiol ligand is phase selectively soluble in alkanes and it quantitatively sequesters common transition metals like Cu2+ and Pd2+ into an alkane phase, separating them from polar solvents in a biphasic liquid/liquid separation. The chelating thioether-thiol ligand was also successfully used to remove Cu and Pd transition metal catalyst residues from products in crude reaction mixtures in both azide/alkyne click reactions and cross-coupling reactions using a liquid/liquid extraction. Separation efficiencies exceeding 95% and in many cases 99% were achieved.

A rationally designed perfluorinated host for the extraction of PFOA from water utilising non-covalent interactions

Three hosts for the encapsulation of perfluorooctanoic acid have been synthesized. The host:guest complexes have been characterized by multinuclear NMR spectroscopy in solution and the solid state.

Laser-driven rapid functionalization of carbon surfaces and its application to the fabrication of fluorinated adsorbers

Rapid functionalisation of carbon surfaces using pulsed UV lasers offers a novel method for capturing fluorinated ligands or pollutants.

Fluorine-fluorine interactions in the solid state: an experimental and theoretical study

The solid state structures of three compounds that contain a perfluorinated chain, CF(3)(CF(2))(5)CH(2)CH(CH(3))CO(2)H, CF(3)(CF(2))(5)(CH(2))(4)(CF(2))(5)CF(3) and {CF(3)(CF(2))(5)CH(2)CH(2)}(3)P═O have been compared and a number of C-F···F-C and C-F···H-C interactions that are closer than the sum of the van der Waals radii have been identified. These interactions have been probed by a comprehensive computational chemistry investigation and the stabilizing energy between dimeric fragments was found to be 0.26-29.64 kcal/mol, depending on the type of interaction. An Atoms-in-Molecules (AIM) study has confirmed that specific C-F···F-C interactions are indeed present, and are not due simply to crystal packing. The weakly stabilizing nature of these interactions has been utilized in the physisorption of a selected number of compounds containing long chain perfluorinated ponytails onto a perfluorinated self-assembled monolayer, which has been characterized by IRRAS (Infrared Reflection Absorption Spectroscopy).

Perfluorinated phosphine oxide and sulfides as extractants for heavy metals and radionuclides

New highly fluorinated monodentate and bidentate phosphine oxide compounds of the type {CF(3)(CF(2))(n)CH(2)CH(2)}(3)PO (n = 5, 9) and [{CF(3)(CF(2))(5)CH(2)CH(2)}(2)P(O)CH(2)CH(2)P(O){CH(2)CH(2)(CF(2))(5)CF(3)}] have been prepared. Their ability to extract a number of metals and radionuclides from aqueous solutions into perfluorinated solvents has been established and the extractable species investigated. All extractants extract the metals As(V), Cd(II), Co(II), Cr(VI), Hg(II), Pb(II), and Sn(II) with >75% removal. In addition, the radioisotopes (90)Sr(II), (133)Ba(II), and U(VI) have been investigated, whilst (59)Fe(III) has been used to model the extraction of plutonium. (133)Ba(II) shows a high distribution ratio for monodentate phosphine oxides, whilst for UO(2)(2+) and (59)Fe(III) bidentate phosphine oxides are superior.

Perfluorinated phenols as extraction agents for Cs+ and Sr2+

The extraction efficiency of some perfluorinated phenols for the removal of Cs+ and Sr2+ from aqueous solutions is reported. The perfluorinated phenols C6F5OH and 2,3,5,6-C6F4HOH have been shown to extract 90Sr2+ or Cs+ from aqueous solutions into a 100:1 mixture of toluene and pyridine in reasonable efficiencies, using radio-tracer and ICP-OES techniques. Additionally uranium, 59Fe3+ {as a model for Pu(IV)} and Eu3+ {as a model for Am(III)} were investigated, with only iron not being successfully extracted.