Near-infrared luminescent mesoporous materials covalently bonded with ternary lanthanide [Er(III), Nd(III), Yb(III), Sm(III), Pr(III)] complexes

New near-infrared-luminescent mesoporous materials were prepared by linking ternary lanthanide (Er³⁺, Nd³⁺, Yb³⁺, Sm³⁺, Pr³⁺) complexes to the ordered mesoporous MCM-41 through a functionalized 1,10-phenanthroline (phen) group 5-(N,N-bis-3-(triethoxysilyl)propyl)ureyl-1,10-phenanthroline. The resulting materials (denoted as Ln(hfth)₃phen–M41 and Pr(tfnb)₃phen–M41; Ln = Er, Yb, Nd, Sm; hfth = 4,4,5,5,6,6,6-heptafluoro-1-(2-thienyl)hexane-1,3-dionate; tfnb = 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedionate) were characterized by powder X-ray diffraction, N₂ adsorption/desorption, and elemental analysis. Luminescence spectra of these lanthanide-complex functionalized materials were recorded, and the luminescence decay times were measured. Upon excitation at the absorption of the organic ligands, all these materials show the characteristic NIR luminescence of the corresponding lanthanide (Er³⁺, Nd³⁺, Yb³⁺, Sm³⁺, Pr³⁺) ions by sensitization from the organic ligands moiety. The good luminescent performances enable these NIR-luminescent mesoporous materials to have possible applications in optical amplification (operating at 1300 or 1500 nm), laser systems, or medical diagnostics.     

Electrometric study of La(III), Ce(III), Pr(III) and Sm(III) complexes of n-glycylglycine

Saxena and co-workers have made extensive study on the complexing tendencies of several thiols and some of the aminoacids with various metals[1–4]. This paper reports the determination of composition and stabilities of La(III), Ce(III), Pr(III) and Sm(III) complexes of N-Glycylglycine at 30° C and 40° C by applying potentiometric and conductometric titration techniques and also the values of ΔG, ΔH and ΔS at 30° C accompanying the complexation reactions. There is however, no reference in the literature on the study of the present system.     

EXTRACTION OF ACTINIDES(III), (IV), (V), (VI), AND LANTHANIDES(III) BY STRUCTURALLY TAILORED DIAMIDES

Eleven diamide extractants having the different backbones were synthesized and their extractability for lanthanides(III) and actinides(III), (IV), (V) and (VI) were measured and compared. The diamides investigated include (CH₂) _n ─(CONR₁,R₂)₂, (n = 0, 1, 2, 3), O─((CH₂) _n′─CONR₁,R₂)₂, S─((CH₂) _n″─CONR₁,R₂)₂, and SS─((CH₂)_n′″─CONR₁,R₂)₂, (n′, n″, n′″ = 1, 2). The diglycolamide introducing an ether oxygen into the main frame, O─(CH₂─CONR₁,R₂)₂, exhibited the highest extractability for An(III), (IV) and (VI), as compared with the other bidentate diamides. It is clear from the present results that the thiadiglycolamide, TDGA, which substitutes ether sulfur atom for oxygen in DGA molecule, also enhances the extraction of actinides. The lanthanide pattern, the distribution ratios versus the atomic number, by diglycolamide in HNO₃-n-dodecane system exhibited a gradual increase of distribution ratio with increase in the atomic number, the opposite trend to that obtained by the other diamides.     

SOLVENT EXTRACTION OF SCANDIUM(III), YTTRIUM(III), LANTHANIDES(III), ANDDIVALENT METAL IONS WITH SEC -NONYLPHENOXY ACETIC ACID

ABSTRACT

Such physicochemical properties of sec-nonylphenoxy acetic acid (CA-100) as the solubility in water, acid dissociation constant in water, dimerization constant in heptane, and distribution constant in organic solvent-water were measured by two-phase titration. The extraction behaviors of scandium (III), yttrium (III), lanthanides (III), and divalent metal ions from hydrochloric acid solutions with CA-100 in heptane have been investigated, and the possibilities of separating scandium (yttrium) from lanthanides and divalent metal ions have been carefully discussed. The stoichiometries of the extracted metal complexes were investigated by the slope-analysis technique. The effect of the nature of diluent on the extraction of yttrium (III) with CA-100 has been studied and correlated with the dielectric constant.     

Synthesis and application of spherical macroporous epoxy–polyamide chelating resin for preconcentration and separation of trace Ga(III), In(III), Bi(III), V(V), Cr(III), and Ti(IV) from solution samples

An ICP‐AES method using a new spherical macroporous epoxy–polyamide chelating resin to enrich and separate trace Ga(III), In(III), Bi(III), V(V), Cr(III), and Ti(IV) ions from solution samples is established. The results show that the analyzed ions can be enriched quantitatively by 0.1 g of the resin at pH 4, with recoveries > 98%. The ions can be desorbed quantitatively with 10 mL of 2M HCl from the resin column with recoveries > 96%, and 100–1000‐fold excesses of Ca(II), Mg(II), Fe(III), Cu(II), Zn(II), Al(III), Ni(II), and Mn(II) cause little interference in the determination of these ions by ICP‐AES. The chelating resin is reused for ten times; the recoveries of these ions are still over 95%. The relative standard deviations for enrichment and determination of 100 ng ml^?1 Ga(III), In(III), and Bi(III), 10 ng ml^?1 V(V), Cr(III), and Ti(IV) are in the range 0.6–2.3%. The concentration of each ion found in the real wastewater sample and alloy sample is in good agreement with the values provided by the plant. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2330–2334, 2005     

Extraction of Pr(III), Nd(III), and Dy(III) from HTFSA Aqueous Solution by TODGA/Phosphonium-Based Ionic Liquids

The extraction behavior of rare earth (RE) elements using N,N,N′,N′-tetraoctyl diglycolamide (TODGA) in an ionic liquid (IL) system was investigated by slope analyses. Metallic salts of Pr(III), Nd(III), and Dy(III) with bis(trifluoromethylsulfonyl)amide (TFSA) were synthesized and studied for their extraction mechanism. The selected concentration of TODGA was diluted with triethylpentylphosphonium bis(trifluoromethylsulfonyl)amide ([P₂₂₂₅][TFSA]) to prepare an extracting phase for the slope analyses. The stoichiometry of RE(III) was determined in order to estimate the extracted species. Furthermore, the complexation state of the extracted species was evaluated by spectroscopic analyses, including Fourier-transform infrared (FT-IR) spectroscopy, Raman spectroscopy, and ultraviolet–visible (UV–Vis) spectroscopy. The FT-IR and Raman spectra were estimated using density functional theory (DFT) calculations. Thorough analysis of the FT-IR spectrum was carried out in order to assign the TODGA group that mainly coordinated the metal ion. The solvation of the [TFSA]^? anion in the coordination sphere of [Nd(TODGA)_(2–3)]³⁺ was investigated by Raman spectroscopic analysis. The coordination ability of TODGA was investigated from the peak shift of the hypersensitive transition (⁴I_9/2→²G_7/2) in UV–Vis spectroscopic measurements. From electrochemical analysis, the extracted [Nd(TODGA)₃]³⁺ complex in [P₂₂₂₅][TFSA] was found to be reduced as per the following reaction: [Nd(TODGA)₃]³⁺ + 3e^? → Nd(0) + 3[TODGA] at ?3.0 V, and the diffusion coefficient of [Nd(TODGA)₃]³⁺ was calculated to be 1.6 × 10^?11 m² s^?1 at 373 K. The direct electrodeposition of the extracted [Nd(TODGA)₃]³⁺ in [P₂₂₂₅][TFSA] at 373 K allowed us to conclude that the middle layer of Nd electrodeposits was the metallic state, while a part of the top surface was the oxidation state by XPS analysis.     

The Effect of Degree of Impregnation in Amberlite Resins with Organophosphorous Extractants for Y(III), La(III), Ce(III), Th(IV) and U(VI) Ions

Abstract

Background: The sorption of Y(III), La(III), Ce(III), U(VI) and Th(IV) ions with solvent impregnated resins using diphenylphosphate (DPP), and diphenylphosphinic acid (DPPA) as extractant and Amberlite XAD 16 and Amberlite XAD 2000 as a polymeric support has been studied. The impregnated resins containing various amounts of extractants (10/90, 20/80, 50/50, 60/40) have been prepared by a dry method. The effects of pH, types of extractant, extractant content, surface area of polymeric support and contact time have been investigated by batch method.

Results: The impregnation for DPP on XAD‐16 and XAD‐2000 was 111 and 46% at 60/40 extractant/resin mass ratio, respectively. The impregnation of DPPA at all ratios on both resins was found constant and lower than DPP. The sorption percentage of studied metal ions was within 90‐99% for DPP and DPPA on both resins after 20/80 extractant/resin mass ratio.

Conclusions: The sorption of DPP on Amberlite XAD 16 and XAD 2000 resins is rather more than DPPA. It could be seen that 20/80 extractant/resin mass ratio is generally adequate for single metal analysis where 60/40 could be suitable for multi‐metal analysis.     

Elution Behavior of Metal Ions with Mixed Glycine-Nitric Acid Eluents in Dowex 50W-X8 Column: Separation of Th(IV), Ce(IV), Bi(III), Fe(III), and Al(III)

Abstract

Distribution coefficients (K) determined by the batch technique in acidic glycine media using Dowex 50W-X8 cation exchanger (H⁺?form, 100–200 mesh size) revealed that this medium can effectively be employed to separate a number of tetravalent and trivalent metal ions from bivalent metal ions. In fixed glycine (0.40 M) and varying concentration of nitric acid (0.10 to 1.0 M), a number of mixtures containing two or three metal ions were resolved on columns using about 8 g of exchanger. In 0.40 M glycine-1.0 M HNO₃ medium, Th(IV)/Ce(IV) were separated from Al(III)/Fe(III)/Bi(III)/Co(II)/Ni(II)/Cu(II)/Zn(II)/Cd(II)/Hg(II)/Pb(II)/Ag(I) and also Al(III)/Bi(III) from a number of divalent metal ions. In 0.40 M glycine-0.50 M HNO₃ medium, the resolution of following ternary mixtures were also achieved: Th(IV)/Ce(IV)-Al(III)/Bi(III)-Fe(III)/Co(II)/Ni(II)/Cu(II)/Zn(II)/Cd(II)/Hg(II)/Pb(II)/Ag(I). Th(IV)/Al(III)/Fe(III)/Bi(III) were also separated from other divalent metal ions in 1.60 M glycine-0.50 M HNO₃ medium. The values of K, elution characteristics of metal ions, elution curves, and the results of the resolution of a number of mixtures of metal ions along with standard deviations are reported.     

Synthesis and characterization of antibacterial polychelates of urea–formaldehyde resin with Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), and Zn(II) metal ions

We studied the reaction between urea and formaldehyde with the purpose of preparing new polychelates of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), and Zn(II) metal ions. These compounds were characterized by elemental analysis, IR spectroscopy, ¹H‐NMR, electronic spectroscopy, thermogravimetric analysis (TGA), and molar conductance measurements. The percentage of metal in all of the polychelates was found to be consistent with 1:1.5 (metal/ligand) stoichiometry. The thermal behaviors of these coordination polymers were studied by TGA in a nitrogen atmosphere up to 750°C. The TGA results reveal that the complexes had higher thermal‐resistance properties compared to the common urea–formaldehyde resin. The molar conductivity and magnetic susceptibility measurements of the synthesized polychelates confirmed the geometry of the complexes. The antibacterial activity of the polychelates was also investigated with agar diffusion methods. The antibacterial activity of these polychelates was found to be reasonably good compared with standard drugs, namely, ciprofloxacin, ampicillin, and kanamycin. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 928–936, 2006     

Extraction Behavior of Zinc(II), Cadmium(II), Mercury(II), Indium(III), and Thallium(III) as Thiocyanates in High-Molecular-Weight Amines and Some Mutual Binary Separations

Abstract

The extraction behavior of Zn(II), Cd(II), Hg(II), In(III), and Tl(III) has been studied at different NH₄CNS molarities in some commercially available liquid anion exchangers. The effect of such variables as the type of amine, molarity of NH₄CNS, and pH of aqueous phase and organic diluent on extraction has been explored to achieve the best conditions of some mutual binary separations of analytical and radiochemical interest.     

Removal of Cu(II), Fe(III), and Cr(III) from Aqueous Solution by Aniline Grafted Silica Gel

Abstract

The aniline moiety was covalently grafted onto silica gel surface. The modified silica gel with aniline groups (SiAn) was used for removal of Cu(II), Fe(III), and Cr(III) ions from aqueous solution and industrial effluents using a batch adsorption procedure. The maximum adsorption of the transition metal ions took place at pH 4.5. The adsorption kinetics for all the adsorbates fitted better the pseudo second‐order kinetic model, obtaining the following adsorption rate constants (k₂): 1.233 · 10^?2, 1.902 · 10^?2, and 8.320 · 10^?3 g · mg^?1 min^?1 for Cr(III), Cu(II), and Fe(III), respectively. The adsorption of these transition metal ions were fitted to Langmuir, Freundlich, Sips, and Redlich‐Peterson isotherm models; however, the best isotherm model fitting which presented a lower difference of the q (amount adsorbed per gram of adsorbent) calculated by the model from the experimentally measured, was achieved by using the Sips model for all adsorbates chosen. The SiAn adsorbent was also employed for the removal of the transition metal ions Cr(III) (95%), Cu(II) (95%), and Fe(III) (94%) from industrial effluents, using the batch adsorption procedure.     

Fluorescence-Responsive Detection of Ag(I), Al(III), and Cr(III) Ions Using Cd(II) Based Pillared-Layer Frameworks

Two Cd(II) based coordination polymers, {Cd₃(btc)₂(BTD-bpy)₂]∙1.5MeOH∙4H₂O}_n (1) and [Cd₂(1,4-ndc)₂(BTD-bpy)₂]_n (2), where BTD-bpy = bis(pyridin-4-yl)benzothiadiazole, btc = benzene-1,3,5-tricarboxylate, and 1,4-ndc = naphthalene-1,4-dicarboxylate, were hydro(solvo)thermally synthesized. Compound 1 has a three-dimensional non-interpenetrating pillared-bilayer open framework with sufficient free voids of 25.1%, which is simplified to show a topological (4,6,8)-connected net with the point symbol of (3²4²56)(3⁴4⁴5⁴6²8)(3⁴4²6¹⁹7²8). Compound 2 has a three-dimensional two-fold interpenetrating bipillared-layer condense framework regarded as a 6-connected primitive cubic (pcu) net topology. Compounds 1 and 2 both exhibited good water stability and high thermal stability approaching 350 °C. Upon excitation, compounds 1 and 2 both emitted blue light fluorescence at 471 and 479 nm, respectively, in solid state and at 457 and 446 nm, respectively, in the suspension phase of H₂O. Moreover, compounds 1 and 2 in the suspension phase of H₂O both exhibited a fluorescence quenching effect in sensing Ag⁺, attributed to framework collapse, and a fluorescence enhancement response in sensing Al³⁺ and Cr³⁺, ascribed to weak ion–framework interactions, with high selectivity and sensitivity and low detection limit.     

Separation of Mercury(II) as Chloride from Zinc(II), Cadmium(II), Gold(III), and Thallium(III) by Extraction in High-Molecular-Weight Amines

Abstract

The extraction behavior of Zn(II), Cd(II), Hg(II), Au(III), and Tl(III) has been studied at different HCl molarities in some commercially available liquid anion exchangers. The effect of such variables as the type of amine, molarity of HCl, amine concentration, and organic diluent on extraction has been explored to suggest the best conditions of separation of Hg(II) from Zn(II), Cd(II), Au(III), and Tl(III).     

SEPARATION OF PALLADIUM(II) FROM PLATINUM(II), IRIDIUM(III), AND RHODIUM(III) USING CENTRIFUGAL PARTITION CHROMATOGRAPHY

The separation of Pd(II) from Pt(II), Ir(III) and Rh(III) with trioctylphosphine oxide (TOPO) in heptane using centrifugal partition chromatography (CPC) has been investigated for the first time. The extraction of Pd(II) has been studied by CPC and batch solvent extraction. The distribution ratios for Pd(II) determined by both methods agree well. In low HCl concentrations (<0.1 M), the extracted species was PdCl₂.(TOPO)₂, irrespective of the chloride concentration, while at acid concentrations above 0.1 M, the Pd was extracted as the ion pair, 2(TOPO.H⁺).PdCl₄ ^2-. Base line separation of Pd(II) and Pt(II) in CPC was obtained under a variety of chloride and HCl concentration with the average number of theoretical plates being 390 ± 40 at a flow rate of 0.47 ± 0.05 mL/min.     

A novel nitronyl nitroxide radical and its Gd(III), Tb(III), Dy(III) complexes: Synthesis,structure and magnetic properties

Three new lanthanide complexes based on a novel nitronyl nitroxide radical [Ln(hfac)₃(NITPhiPr)₂] (Ln = Gd(1), Tb(2), Dy(3); hfac = hexafluoroacetylacetonate, NITPhiPr = 4′-isopropyl-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) have been successfully synthesized, characterized structurally and magnetically, which all display radical-Ln(III)-radical tri-spin structures. The magnetic studies reveal the ferromagnetic interactions between the Gd(III) ion and radicals and the antiferromagnetic interaction between two radicals in the complex 1. And both Ln(III)–radical ferromagnetic interactions exist in complexes 2 and 3.     

Adsorption of Cr(III), Ni(II), Zn(II), Co(II) ions onto phenolated wood resin

In this study, phenolated wood resin was used an adsorbent for the removal of Cr(III), Ni(II), Zn(II), Co(II) ions by adsorption from aqueous solution. The adsorption of metal ions from solution was carried at different contact times, concentrations and pHs at room temperature (25°C). For individual metal ion, the amount of metal ions adsorbed per unit weight of phenolated wood resin at equilibrium time increased with increasing concentration and pH. Also, when the amounts of metal ions adsorbed are compared to each other, it was seen that this increase was order of Cr(III) > Ni(II) > Zn(II) > Co(II). This increase was order of Cr(III) > Ni(II) > Co(II) > Zn(II) for commercial phenol–formaldehyde resin. Kinetic studies showed that the adsorption process obeyed the intraparticle diffusion model. It was also determined that adsorption isotherm followed Langmuir and Freundlich models. Adsorption isotherm obtained for commercial phenol–formaldehyde resin was consistent with Freundlich model well. Adsorption capacities from Langmuir isotherm for commercial phenol–formaldehyde resin were higher than those of phenolated wood resin, in the case of individual metal ions. Original adsorption isotherm demonstrated the monolayer coverage of the surface of phenolated wood resin. Adsorption kinetic followed the intraparticle diffusion model. The positive values of ΔG° determined using the equilibrium constants showed that the adsorption was not of spontaneous nature. It was seen that values of distribution coefficient (K_D) decreasing with metal ion concentration in solution at equilibrium (C_e) indicated that the occupation of active surface sites of adsorbent increased with metal ions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2838–2846, 2006     

Separation and concentration processes of solutions of Co(II), Ni(II), Cr(III), Fe(III) and Mn(II) by extraction with toluene-dissolved rosin

The extraction and stripping of Co(II), Ni(II), Cr(III) and Fe(III) from aqueous solutions by rosin dissolved in toluene has been investigated. Results obtained show that rosin is better extractant than abietic or n-lauric acids under comparable conditions. From these results, and the data of Mn(II) solvent extraction studied previously under the same conditions, a separation and concentration process for these five cations in aqueous solutions has been designed. Saturated solutions of Fe(III), Cr(III), Mn(II) and finally Co(II) and Ni(II) have been obtained successively by extraction and stripping, by addition of ammonium hydroxide to obtain the appropriate pH value, and by modifying adequately the organic phase/aqueous phase volume ratio.     

Separation of La(III), Eu(III), and Ho(III) with Sorbents Impregnated by Mixtures of Acidic Phosphoryl Podands and Amines in Nitric Acid Solutions

ABSTRACT

The possibility of separation of La(III), Eu(III), and Ho(III) as respective individual representatives of light, medium, and heavy rare earth elements was studied using sorbents impregnated by mixtures of acidic phosphoryl podands derived from diethylene glycol and octyl, dioctyl, and trioctyl amines from nitric acid solutions of various concentrations. The influence of the phosphoryl podands structure, their percentage content, and proportion in a sorbent and the nature of an acid on the efficiency of separation of La(III), Eu(III), Ho(III) was studied. It is shown that the greater is the concentration of HNO₃, the smaller are the separation factors of REEs, and remarkably so. The most efficient separation is achieved with the concentration of HNO₃ not over 0.04 mol/L. The optimal conditions of separation of La(III), Eu(III), and Ho(III) with the developed sorbent were found. Repeated use of the sorbent for the separation of La(III), Eu(III), and Ho(III) after its regeneration with 0.04 mol/L HNO₃ was estimated. It was found that the efficiency of separation of REEs with the sorbents impregnated by a mixture of 1,5-bis(2-oxyethoxyphosphoryl-4-ethylphenoxy)-3-oxapentane and trioctylamine (TOA) exceeds markedly that made of a mixture of di-(2-ethylhexyl)phosphoric acid (DEHPA) and TOA.     

Synthesis and magnetic properties of novel complexes of poly(N‐2‐thiazolylmethacrylamide) with Nd(III), Pr(III), and Sm(III)

N‐2‐Thiazolylmethacrylamide (NTMA) was polymerized by a radical route to obtain the polymer in good yields. The complexes of PolyNTMA with three rare earth ions Nd(III), Pr(III), and Sm(III) were prepared for the first time. FTIR and ¹H NMR were applied to characterize these materials. The magnetic behavior of PolyNTMA–metal complexes was examined as a function of applied magnetic field at 4 K and as a function of temperature (4–300 K) at an applied magnetic field of 30 kOe. It was found that Pr(III) complex exhibits an antiferromagnetic property, while Nd(III) and Sm(III) complexes exhibit a special magnetic property different from the typical magnet. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1289–1293, 2006