Extraction and separation of heavy rare earth (III) with Extraction Resin containing di(2,4,4-trimethyl pentyl) phosphinic acid (Cyanex 272)

Extraction resins, of the type of;levextrel, (which is a collective term for styrene/divinylbenzene based copolymers of predominantly macroporous structure that contain a selective extractant) are important for the recovery and separation of metal ions, as they combine features of solvent extraction and ion exchange resins. This paper presents the results of the adsorption of heavy rare earth ions (Ho(III), Er(III), Tm(III), Yb(III), Lu(III) and Y(III)) from hydrochloric acid solutions at 0.2 mol/L ionic strength and 50 degrees C by the extraction resin containing di (2,4,4-trimethyl pentyl) phosphinic acid (Cyanex 272) and the chromatographic separation of (Er(III), Tm(III) and Yb(III)). Technological separation products, with purity and yield of Tm2O3 >99.97%, >80%, Er2O3 >99.9%, >94% and Yb2O3 >99.8%, >80% respectively, have been obtained from a feed having the composition Tm2O3 60%, Er2O3 10%, and Yb2O3 3%, the others 27%. The distribution coefficients, extraction equilibrium constants and separation factors have been determined as a function of acidity, loading of the resin and rare earths, flow rates and column ratios. The resolutions and efficiencies of separation of Er/Tm/Yb each other have been calculated. The stoichiometry of the extraction of rare earth ions has been suggested as well.

Bright red electroluminescent devices based on a soluble lanthanide complex Eu(DBM)(3)(phen)

Electroluminescent devices with PVK film doped with Eu(DBM)(3)(phen) and PBD were fabricated. The device structure of glass substrate/indium-tin-oxide/PPV/PVK:Eu(DBM)(3)-(phen):PBD/Alq(3)/Al was employed. The emissive layer was formed by spin-casting method. A sharply red electroluminescence with a maximum luminance of 114.4 cd/m(2) was achieved at 42 V.

Synthesis and X-ray crystal structure of [(eta(5)-C5H5)Sm(mu-OC20H20N2O)](2)(mu-THF)(THF)(2): Mono(cyclopentadienyl)lanthanide complex bearing a C-2-symmetric tetradentate Schiff-base ligand

Cp2SmCl(THF) reacts with 0.5 equivalent disodium salts of trans-(+/-)-N,N'-bis(salicylidene)-1,2-cyclohexanediamine give the title complex [(eta(5)-C5H5)Sm(mu-OC20H20N2O)](2)(mu-THF)(THF)(2) (1). X-ray crystal determination shows that the molecule is a dimer, in which two (eta(5)C(5)H(5))Sm(mu-OC20H20N2O) units are connected via a THF oxygen and two bridging oxygen atoms of Schiff base ligands. The average Sm-C distance is 2.78(7) Angstrom, while those of Sm-O (bridging THF oxygen) and Schiff base oxygens are 2.79(3) and 2.43(4) Angstrom; respectively. (C) 1998 Elsevier Science Ltd. All rights reserved.

Electrochemical studies of a lanthanide heteropoly tungstate/molybdate complex in polypyrrole film electrode and its electrocatalytic reduction of bromate

An electrode modified with a polybasic lanthanide heteropoly tungstate/molybdate complex K10H3[Nd(SiMo7W4O39)(2)] entrapped into polypyrrole (PPy) film, denoted as Nd(SiMo7W4)(2)-PPy, exhibits three couples of two-electron redox waves in pH 1-5 buffer solutions. The redox waves are surface-controlled at lower scan rates and diffusion-controlled at higher scan rates. The effects of pH on the electrochemical behavior of Nd(SiMo7W4)(2) in PPy film were investigated in detail and compared with that of Nd(SiMo7W4)(2) in aqueous solution. The various charge states of PPy during its redox process have peculiar effects on the relationship between pH and formal potentials of Nd(SiMo7W4)(2)-PPy at different acidities. The Nd(SiMo7W4)(2)-PPy cme can remarkably catalyze the electrochemical reduction of bromate with good stability. (C) 1997 Elsevier Science Ltd.

Luminescence properties of the Langmuir-Blodgett film of terbium(III) stearoylanthranilate

Terbium(III) stearoylanthranilate has been prepared as a high property Z-type Langmuir-Blodgett (LB) film on various substrates by a vertical transfer process. The UV-visible absorption spectra and the low angle X-ray diffraction peaks have been collected in order to investigate the molecular arrangement and aggregation in the LB films. The average molecular orientation in multilayer stacking was determined by Attenuated Total Reflection Spectroscopy. The influence of the chemical environment of terbium within the LB films on the luminescence properties has been discussed. (C) 1997 Elsevier Science S.A.

Syntheses of indenyl lanthanide derivatives and the molecular structures of [(C9H7)(2)PrCl(THF)](2) and [(C9H7)(3)La(THF)]

The reaction of anhydrous PrCl3 with Na(C9H7) in 1.2 mole ratio in THF gives [(C9H7)(2)PrCl(THF)](2)1. 1 crystallized in monoclinic system, space group P2(1)/c with a = 7.808(2), b = 17.796(6), c = 14.070(4) Angstrom, beta = 93.97(2)degrees, V= 1950.3(9) Angstrom(3), Dcalcd = 1.63 g/cm(3) and Z = 2. Each Pr ion is surrounded by two indenyl, two Cl and one THF in a roughly trigonal bipyramid arrangement with average Pr-C(ring) and Pr-Cl distances of 2.81 and 2.84 Angstrom. The reaction of LaCl3 with Na(C9H7) in 1:3 mole ratio gives (C9H7)(3)LaTHF 2, which crystallizes in the monoclinic space group P2(1)/a with unit cell constants a = 21.871(8), b = 10.585(3), c = 23.652(7) Angstrom,beta = 114.62(2)degrees, V = 4977.9 Angstrom(3) and Z = 8. (C) 1997 Elsevier Science S.A.

Ab initio study on the interaction of La (III) with adrenaline

The interaction of La(III) with adrenaline was studied using Ab initio method. The geometry of the complex of La (III) with adrenaline was optimized, and the La(III) bonding site in adrenaline was ascertained.

Studies on the coordination of lanthanide with L-hydroxyproline and DL-citrulline

The stability constants of binary and ternary complexes of lanthanide with L-hydroxyproline and DL-citrulline were obtained by using potentiometric titration under the physiological condition(37 degrees C, 0.15 mol/L NaCl). The coordination of lanthanide with the two ligands was discussed.

Investigation on molecular and crystal structures of metal complexes with aminopolycarboxylic acids .1. Synthesis and structure of Na-2[Fe-III(ida)(2)](2)center dot 3H(2)O

The crystal structure of the title complex salt has been determined by single-crystal X-ray structure analysis. The crystal data areas follows; Monoclinic, P2(1)/c, a=15.6480(10)Angstrom, b=16.7870(10)Angstrom, c=10.347(2)Angstrom, beta=90.790(10), V=2717.7(6)Angstrom(3), Z=3, and R=0.0333 for 4789 unique reflections. The complex anion has a pseudo-octahedral structure distorted more than the Cr-III and Co-III analogs, in which each, iminodiacetato ligand (ida(2-)) is coordinated in a facial fashion with the two N atoms in a cis configuration, resulting in an unsym-fac structure.

Stereospecific polymerization of styrene using a homogeneous lanthanide catalyst

Stereospecific polymerization of styrene was catalyzed by homogeneous neodymium phosphonate [Nd(P-507)(3)]-H2O-Al(i-Bu)(3) catalytic system. The polymer was separated into isotactic polystyrene and atactic polystyrene by extracting the latter with boiling 2-butanone. The conversion of styrene and the yield of isotactic polystyrene (IY) were influenced by the [H2O]/[Al(i-Bu)(3)] mole ratio and the solvent polarity. The reaction is first order with respect to monomer at 70 degrees C.

Studies on synergistic extraction of Sc(III) with HBTMPTP and Cyanex 925

The synergistic extraction of Sc(III) from H2SO4 solution with bis(2, 4, 4-trimethylpentyl)monothiophosphinic acid(HBTMPTP, HL) and branched chain alkyl phosphine oxide mixture (Cyanex 925, B) in n-hexane has been investigated, The results indicated that synergistic effect was showed in low acidity (c(H2SO4) < 0.25 mol/L). The composition of the extracted complex of Sc(III) has been determined to be Sc(HL2)(2)B-3(SO4)(1/2) by the method of slope analysis, The mechanism of the synergistic extraction of Sc(III) may be : Sc3+ + 2(HL)(2(O)) + 3B((O)) + 1/2SO(4)(2-)reversible arrow(K12)Sc(HL2)(2)B-3(SO4)(1/2(O)) + 2H(+) ScL(HL2)(2(O)) + 3B((O)) + H+ + 1/2SO(4)(2-)reversible arrow(beta')Sc(HL2)(2)B-3(SO4)(1/2(O)) + 1/2(HL)(2(O)) Sc(SO4)(1.5)B-2(O) + B-(O) + 2(HL)(2(O))reversible arrow(beta')Sc(HL2)(2)B-3(SO4)(1/2(O)) + 2H(+) + SO42- Their equilibrium constants have been calculated to be lgK(13)=6.77+/-0.12, lg beta'=7.71, lg beta '' = 0.10, respectively, The IR spectra and FAB-MS of the saturated synergistic extraction complex of Sc(III) have been discussed as well.

Crystal structure of a Pr-III complex with a novel macrocyclic ligand

The crystal structure of a novel macrocyclic ligand complex of Pr-III, C112H178O52N8S4Pr2, [Pr2L2(HL)(2)(H2O)(6)]. 22H(2)O is reported. The macrocyclic ligand has pendant acetic acid through which the ligand is coordinated to the Pr-III ion. For the dimeric unit, [Pr2L2(HL)(2)(H2O)(6)], two Pr-III ions are connected by two bridging-chelating carboxyl groups and two bridging carboxyl groups of the ligands, and each Pr-III ion is also bonded to a unidentate carboxyl group of the ligand and three water molecules. The dimeric units are bridged by four ligands through their carboxyl groups to form an infinite one-dimensional chain. The coordination number of the Pr-III ion is nine, with a distorted tricapped trigonal prismatic configuration. (C) 1997 Elsevier Science Ltd.

Hydrothermal synthesis and lanthanide doping of complex fluorides, LiYF4, KYF4 and BaBeF4 under mild conditions

The complex fluorides LiYF4, KYF4, BaBeF4 and AYF(4)Eu(x) (A = Li, K) are hydrothermally synthesized at 140-240 degrees C and characterized by powder X-ray diffraction, thermogravimetric analysis, IR spectroscopy, scanning electron microscopy and luminescence measurements.