High Selectivity For Copper Research Articles

Two sensors based on π-extended TTF: synthesis and high selectivity for copper(II)

Two novel donor-π-acceptor chemosensors, exTTF-DPA and exTTF-ADPA, based on π-extended tetrathiafulvalene (exTTF) and di(pyridine-2-ylmethyl)amine (DPA) were synthesized and used as optical and electrochemical chemosensors for copper(II). The results showed that they possess specific selectivity for copper(II) in the presence of other competing metal ions (Zn2+, Sn2+, Pb2+, Pd2+, Hg2+, Al3+, Fe3+, Ag+, Co2+, Ni2+) in acetonitrile. Upon the addition of Cu2+, the solution color changed from yellow to orange, the cyclic voltammograms changed dramatically and the fluorescence quenched completely.

Highly sensitive and selective fluorescence detection of copper (II) ion based on multi-ligand metal chelation

A fluorescent probe was synthesized and demonstrated to be highly selective and sensitive in the reaction with copper (II) ion, generating a large variation of the fluorescence intensity in a dose–response manner. The probe contains a dansyl moiety as fluorophore and a multidentate ligand for copper (II) ion recognition. The reaction of the molecular probe with copper (II) ion proceeds rapidly and irreversibly in a 1 to 1 stoichiometric way, leading to the production of stable copper (II) complex, which subsequently results in the quenching of fluorescence. The detection limit for copper (II) ion was measured to be about 2ppb. It was also shown that the probe has high selectivity for copper (II) ion and good anti-interference ability against other transition metal ions. The herein reported very simple and reliable fluorescence probe could be employed for copper (II) ion detection in many aspects.

Radiolabeling of HTE1PA: A new monopicolinate cyclam derivative for Cu-64 phenotypic imaging. In vitro and in vivo stability studies in mice

IntroductionHTE1PA, a monopicolinate-N-alkylated cyclam-based ligand has previously demonstrated fast complexation process, high kinetic inertness and important thermodynamic and electrochemical stability with respect to natural copper. In this work we first developed a new synthetic route to obtain HTE1PA in good yields. Then, we investigated HTE1PA chelation properties towards copper-64 and assessed in vitro and in vivo stability of the resulting compound. MethodsRadiolabeling of HTE1PA with copper-64 was tested at different ligand concentrations in ammonium acetate medium. In vitro stability study was carried out by incubating [64Cu]TE1PA complex in human serum at both 37°C and 4°C; chromatographic controls were performed over 24h. Biodistribution, pharmacokinetic and hepatic metabolism of [64Cu]TE1PA were conducted in BALC/c mice in comparison with [64Cu]acetate and [64Cu]DOTA, used as a reference ligand. ResultsThe promising results obtained for natural copper complexation were confirmed. HTE1PA was quantitatively radiolabeled in 15min at room temperature. The resulting complex showed high serum stability. [64Cu]TE1PA induced a significant uptake in the liver and kidneys at early biodistribution time point. Nevertheless, a high speed wash out was observed at 24h leading to significantly lower uptake into the liver compared to [64Cu]DOTA. The metabolism study was consistent with a high resistance to transchelation as the initial uptake into liver matches with the intact form of [64Cu]TE1PA. ConclusionDespite the partial elimination of HTE1PA – as copper-64 complex – through the hepatic route, its high selectivity for copper and its resistance to transchelation make it a promising ligand for antibody radiolabeling with either copper-64 or copper-67.

Hydrometallurgical recovery of copper from complex mixtures of end-of-life shredded ICT products

Hydrometallurgical recovery of copper from complex fine mixture scrap generated by shredding EoL (end-of-life) ICT (information and communications technology) products has been experimentally investigated. Tested leaching agents include sulphuric acid, ammonia–ammonium carbonate and ammonia–ammonium sulphate solutions, with or without addition of hydrogen peroxide. The results show that ammonia leaching has high selectivity for copper, and it could serve as a first step to recover the copper content in the e-waste, which is one of the major valuable metals. The feasibility of direct electrowinning of copper from the ammonia leaching solution with about 20g/l Cu was investigated. Copper with 98.9% purity was obtained, with a current efficiency of 50–70% and the major impurity of Pb. The product purity could be improved with solution purification and adoption of inert anode.

Selective extraction and transport of copper(II) with new alkylated pyridinecarboxylic acid derivatives

Two kinds of N-(6-alkylamido)-2-pyridine carboxylic acid with a pyridine moiety and a carboxylic acid as chelating ligands were newly synthesized for the selective extraction and the transport of copper(II) from aqueous solution. Liquid–liquid extraction was carried out to examine the extraction ability of extractants with metal ions. The selectivity for the metal ions with N-6-(2-ethylhexylamido)-2-pyridine carboxylic acid (EHPA) was in the following order: Cu(II)≫Zn(II) ≈ Pb(II) ≈ Ni(II) ≈ Co(II) > Cd(II) > Mn(II). All metals tested in this study were selectively extracted at a lower pH by 2–3 units compared with commercial available alkyl carboxylic acids such as naphthenic acid and Versatic 10. The extraction equilibria of copper(II) were measured by a batchwise method at 303 K with EHPA and N-6-( t-dodecylamido)-2-pyridinecarboxylic acid ( t-DAPA). Copper(II) was extracted as a 1:2 complex according to the following reaction: C u 2 + + 2 ( HR ¯ ) 2 = Cu R 2 2 HR ¯ + 2 H + . The extraction equilibrium constant, K ex was evaluated and the values were found to be 1.13 and 0.31 for EHPA and t-DAPA, respectively. It was demonstrated that t-DAPA was very stable to be incorporated into a polymer inclusion membrane (PIM) consisting of cellulose triacetate (CTA) as a base polymer and 2-nitrophenyl octylether (NPOE) as a plasticizer. This novel PIM containing t-DAPA as a carrier exhibited an excellent copper(II) transport characteristic and a high selectivity for copper(II) over cadmium(II) from aqueous solution.

New hybrid chelating sorbents with grafted 3-aminopropionate groups based on mixed silicon, aluminum, titanium, or zirconium oxides

A series of new hybrid organo-inorganic sorbents with the 3-aminopropionate chelating group was synthesized. The synthesis includes the copolycondensation (sol—gel method) of tetraethoxysilane, 3-aminopropyltriethoxysilane, and several modifiers (MeSi(OEt)3, EtSi(OEt)3, Ti(OEt)4, AlONO3, ZrOCl2) followed by carboxyethylation with acrylic acid. The obtained chelating sorbents were characterized by elemental analysis, FT-IR and 1H NMR spectroscopy, and thermogravimetry. The N-carboxylated sorbents have a higher sorption capacity with respect to metal ions (0.5–0.9 mmol g−1, pH 6.3, NH4OAc, 20 °C) than the starting sorbents with the primary amino group (0.05–0.2 mmol g−1) and manifest high selectivity for copper(II) ion extraction.

Metal ion recognition. Interaction of a series of successively N-benzylated derivatives of 1,4,8,11-tetraazacyclotetradecane (cyclam) with selected transition and post-transition metal ions

The interaction of a series of N-benzylated cyclam ligand derivatives incorporating from one to four N-benzyl groups with cobalt(II), zinc(II), cadmium(II), lead(II) and silver(I) nitrates is reported; the results are compared with those obtained in a prior study involving the formation of the corresponding complexes of nickel(II) and copper(II) with this ligand series. The isolation of a selection of 1 ∶ 1 (metal ∶ ligand) complexes has been carried out and X-ray diffraction structures of five such products have been determined. In each complex the metal ion is coordinated to the N4-donor set of the cyclam ring with the latter adopting either a trans-I or a trans-V configuration; monodentate or bidentate nitrato ligands complete the respective coordination spheres. Coordination numbers range from five in a zinc(II) complex, through six in two cadmium(II) complexes, to eight in two lead(II) complexes. Competitive bulk membrane transport experiments (water/chloroform/water) have been carried out in which each of the five benzylated ligands were in turn employed as the ionophore in the chloroform phase. The respective aqueous source phases (buffered at pH 4.9) contained an equimolar mixture of cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II), silver(I) and lead(II) nitrates. The aqueous receiving phase was buffered at pH 3.0. Under these conditions, high selectivity for copper(II) was observed for each of the ionophores incorporating one or two N-benzyl groups whereas no transport for any of the seven metals present in the source phase was observed for the tribenzylated derivative. In marked contrast to the above behaviour, the tetra-N-benzyl derivative yielded sole transport selectivity for silver(I) under similar conditions. 1H NMR and 13C NMR titration experiments in CD3CN–CDCl3 confirmed the 1 ∶ 1 stoichiometry of the silver(I) tetra-N-benzylcyclam complex in this solvent mixture.

Synthesis of Copper(II) Selective Chelating Resin Bearing a Tetraaza Macrocyclic Schiff Base Ligand

Abstract The chelating resin bearing a tetraaza macrocyclic Schiff base ligand as a pendant group has been synthesized and found to have a high selectivity for copper(II) over nickel(II). This resin can be applied to a useful adsorbent for efficient separation of these metal ions in a column system.

SYNTHESIS OF MACROCYCLIC SCHIFF BASE POLYMER LIGAND AS A HIGHLY SELECTIVE EXTRACTANT FOR COPPER(II)

Abstract A novel polymer ligand (Poly-L) in which 6,8,15,17-tetramethyl-dibenzo-5,9,14,18-tetraazacyclotetradecene (L) is present as an integral part of the polymer backbone was synthesized and its solvent extraction of copper(II) and nickel(II) was investigated in comparison with L. The complexation reactions of Poly-L with the above metal ions were found to be much faster than those of L, with a high selectivity for copper(II).