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Kinetic and spectral studies of EHPG systems using chemi-and electrochemiluminescence methods

Journal of Rare Earths 2010年第6期28卷 868-873页

作者： S. Lis M. Kaczmarek K. Staninski S. Krompiec N. Kuznik Faculty of Chemistry Adam Mickiewicz University Institute of Chemistry University of Silesia Faculty of Chemistry Silesian Technical University

The systems containing EHPG, EHPG-OCH3 and EHPG-NH-Ac and Tb(Ⅲ) ions were used to study chemiluminescence (CL) and electrochemiluminescence (ECL) processes. In the CL studies the Fenton system (Fe(Ⅱ)/(Ⅲ)-H2O2) was used as a source of reactive oxygen species (ROS). Kinetic CL curves and CL spectral distributions were recorded. On the basis of the results obtained, it was demonstrated that Tb(Ⅲ) acted as a sensitizer. Similarly obtained CL decays in the systems of Fe(Ⅱ)/(Ⅲ)-EHPG (or its derivatives)-H2O2 and Fe(Ⅱ)/(Ⅲ)-EHPG (or its derivatives)-Tb(Ⅲ)-H2O2, independently on the Tb(Ⅲ) concentration, showed that the lanthanide ions did not influence the kinetics of the oxidation of EHPG (or its derivatives) in the Fenton systems. The CL intensity increased with the increasing concentration of Tb(Ⅲ) ions, which were the main emitters in the reaction systems. Spectrophotometric and luminescent studies of the systems before and after the additions of hydrogen peroxide proved that the excitation of the lanthanide ion was a result of energy transfer from the excited products of the oxidation of EHPG or its derivatives to the uncomplexed Tb(Ⅲ) ions. ECL was generated on the surface of a nonstructural modified aluminum electrode with the use of K2S2O8, H2O2 or KN3 as coreactants in aqueous solution. In these studies we employed Al electrodes covered with a 2-4 nm layer of Al2O3 doted with Tb(Ⅲ) or Dy(Ⅲ) ions. The electrodes were polarized using cathodic and anodic pulses of various amplitude and frequency. The relative ECL efficiencies were determined as a function of electric pulse parameters, electrolyte compositions and the thickness of barrier or porous layer of the Al2O3 electrode.

关键词： chemiluminescence lanthanides EHPG complexes rare earths

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Electrochemical studies on cerium(Ⅲ) in molten fluoride mixtures

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Journal of Rare Earths 2010年第3期28卷 428-434页

作者： VIRGIL CONSTANTIN ANA-MARIA POPESCU MIRCEA OLTEANU Romanian Academy Institute of Physical Chemistry "Ilie Murgulescu"Department of Molten Salts Splaiul Independentei 202Bucharest-Romania

This study aims to determine the principal electrochemical characteristics of the electrodeposition of cerium metal from molten fluoride *** cathodic process of Ce3+ ions in LiF-NaF and LiF-NaF-CaF2 molten salts was studied using electrochemical techniques as steady state and cyclic voltammetry *** decomposition potential(Ed) and the overvoltage(η) were determined for NaCeF4 using current-potential curves under galvanostatic *** Ed was found to be 2.025 V in LiF-NaF and 2.045 V in...

关键词： cerium molten salts lanthanides NaCeF4 electrolysis cyclic voltammetry

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Influence of non-covalent interactions on properties of lanthanide systems with aromatic ligands

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Journal of Rare Earths 2008年第2期26卷 146-152页

作者： Lada Puntus Konstantin Lyssenko Laboratory of Molecular Nanoelectronics Institute of Radioengineering & Electronics Russian Academy of Sciences 11-7 MokhovayaMoscow 125009 Russia A. N. Nesmeyanov Institute of Organoelement Compounds Russian Academy of Sciences GSP-1 28 Vavilov StreetMoscow 119991 Russia

Two series of lanthanide compounds, namely, chlorides containing different numbers of both 1,10-phenanthroline （Phen） molecules and chloride anions in the first coordination sphere, and Schiff Bases （SBs） derived from Pyridoxal （PL） and amino acids, were characterized by single crystal X-ray diffraction and luminescence techniques. The combined use of these techniques for the analysis of long-distance europium non-covalent interactions was performed for the first time. As a result, the correlation between supramolecular organization and the features of the Eum electronic transitions was found for the compounds of the first series. Strong non-covalent interactions between pyridoxal tings of SBs （the second series of compotmd） led to the formation of 1：2 species and four-dentate coordination function of these SBs in aqueous solution.

关键词： n-stacking interaction luminescence lanthanides halogenides Schiff base rare earths

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Ion imprinted polymer particles of neodymium:synthesis,characterization and selective recognition

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Journal of Rare Earths 2009年第1期27卷 22-27页

作者：郭佳佳蔡继宝苏庆德 Department of Chemistry University of Science and Technology of China

Neodymium ion imprinted polymer（Nd^3＋-IIP） particles for selective solid-phase extraction of Nd^3＋ were prepared and determined with inductively coupled plasma atomic emission spectrometry（ICP-AES）.The unleached Nd^3＋-IIP particles were prepared by the copoly-merization of Nd^3＋-5,7-dichloroquinoline-8-ol-4-vinylpyridine ternary complex with styrene and divinyl benzene, then Nd^3＋ was leached to obtain Nd^3＋-IIP *** adsorption capacity of the Nd3＋-IIP was 35.18 mg/*** largest selectivity coefficient for Nd3＋ in the presence of competitive ions such as La^3＋, Ce^3＋, Pr^3＋ and Sm^3＋ was over *** proposed method was validated by analyzing two certified reference materials（GBW07301a sediment and GBW07401 soil） and the determined values were in a good agreement with standard *** method was convenient, selective, sensitive and applicable to the determination of trace Nd^3＋ in environmental samples with complicated matrix.

关键词： ion imprinted polymer neodymium ion selective separation lanthanides

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A stimuli responsive lanthanide-based hydrogel possessing tunable luminescence by efficient energy transfer pathways

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Journal of Rare Earths 2022年第5期40卷 696-701,I0001页

作者： Yuan Wang Jinglei Chen Yuan Shang Peng Li Huanrong Li Tianjin Key Laboratory of Chemical Process Safety School of Chemical Engineering and TechnologyNational-Local Joint Engineering Laboratory for Energy Conservation in Chemical Process Integration and Resources UtilizationHebei University of TechnologyTianjin 300130China

Energy transfer as an important component in light-harvesting antenna systems can mimic effectively natural photosynthesis processes,showing great potential in optoelectronic ***,we report a responsive polymeric hydrogel based on the combination of excited state intramolecular proton transfer(ESIPT) molecule(Salicylic acid,Sal) and terbium(Ⅲ)(Tb^(3+)),as enabled by external stimuli to construct artificial light-harvesting antenna *** from unique photophysical properties of Sal,the synthesized hydrogel displays a temperature-dependent reversible opaque?transparent states transition,accompanied with an interesting photoluminescence ***,by further incorporating europium(Ⅲ)(Eu^(3+)) into the hydrogel,we demonstrate well-defined cascades of energy transfer that provides a tunable optical output from the collection of lanthanides by the excitation of a common sensitizer(Sal) upon base vapor *** energy transfer efficiency from Tb^(3+) to Eu^(3+),as high as 97.8%,was also obtained as established by the time-resolved fluorescence spectroscopy analysis.

关键词： Energy transfer lanthanides Stimuli-responsive hydrogel Luminescence Rare earths

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Molecular modeling of the octacoordinated tetracarbonato-Nd(III), [Nd(CO_3)_4]^(5-), complex and its nonacoordinated fluoro- and aquo-adducts

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Journal of Rare Earths 2010年第6期28卷 847-853页

作者： S. P. Sinha Alfredo M. Simas Gustavo L. C. Moura Scientific Research & Development Departamento de Quimica Fundamental CCEN Universidade Federal de Pernambuco

Theoretical investigation on the structures of the octacoordinated [Nd(CO3)4]5-and the nonacoordinated [Nd(CO3)***2]5-complexes, using the SPARKLE parameters of the lanthanides within MOPAC, revealed that they possessed dodecahedral and square antiprismatic structures respectively with an average Nd-O distance of 0.249 nm. These structures and the Nd-O distances agreed well with those experimentally found in the crystal structures. Replacing the water molecule with a fluoride ion or a mondentatecarbonato ligand resulted in a nonacoordinated distorted square antiprismatic structures where the trans-carbonato groups were twisted. The corresponding decacoordinated structures with two fluoride ions or a bidentatecarbonato group, [Nd(CO3)4·F2]7-and [Nd(CO3)5]7-, were also investigated. In both cases considerable twisting of the transcarbonato groups was observed.

关键词： lanthanides theoretical molecular models octacoordination carbonato complexes adducts MOPAC SPARKLE rare earths

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Synthesis,spectroscopic characterization,DNA cleavage and antibacterial studies of a novel tridentate Schiff base and some lanthanide(III) complexes

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Journal of Rare Earths 2014年第4期32卷 379-388页

作者： K.Mohanan R.Aswathy L.P.Nitha Niecy Elsa Mathews B.Sindhu Kumari Department of Chemistry University of Kerala Department of Chemistry Mother Teresa Women's University

A novel potential tridentate Schiff base was prepared by condensing equimolar quantities of 2-hydroxyacetophenone and 2-aminopyrimidine in methanol. This ligand was versatile in forming a series of complexes with lanthanide ions such as La（III）, Pr（III）, Nd（III）, Sm（III）, Gd（III）, Dy（III） and Yb（III）. The ligand and the metal complexes were characterized through elemental analysis, molar conductance, UV-Visible, IR, 1H NMR, and mass spectral studies. The spectral studies indicated that the ligand was coordinated to the metal ion in neutral tridentate fashion through the azomethine nitrogen, one of the nitrogen atoms in the pyrimidine ring and the phenolic oxygen without deprotonation. Thermal decomposition and luminescence property of lanthanum（III） complex were also examined. The X-ray diffraction patterns showed the crystalline nature of the ligand and its lanthanum（III） complex. The DNA cleavage studies of the ligand and the metal complexes were carried out and it was observed that the lanthanum（III） and neo-dymium（III） complexes cleaved the pUC19 DNA effectively. The ligand and the metal complexes were screened for their antibacte-rial activities. The metal complexes were found to be more potent bactericides than the ligand.

关键词： 2-aminopyrimidine lanthanides thermogravimetry luminescence DNA cleavage antibacterial activity rare earths

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Synthesis, spectroscopic characterization, and thermal decomposition kinetics of some lanthanide(III) nitrate complexes of 2-(N-o-hydroxyacetophenone) amino-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene

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Journal of Rare Earths 2008年第4期26卷 463-468页

作者： K. Mohanan M. Thankamony B. Sindhu Kumari Department of Chemistry University of Kerala Kariavattom Campus Trivandrum-695 581. Kerala India

Complexes of La（Ⅲ）, Ce（Ⅲ）, Pr（Ⅲ）, Nd（Ⅲ）, Sm（Ⅲ）, Eu（Ⅲ）, Gd（Ⅲ）, Dy（Ⅲ）, Yb（Ⅲ）, and Lu0ID with 2-（N-o- hydroxyacetophenone）amino-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene （HAAT） formed by the condensation of o-hydroxyacetophenone and 2-amino-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene were synthesized and characterized on the basis of elemental analyses, molar conductance measurements, magnetic susceptibility data, UV-Visible, IR, and NMR spectral studies. The spectral data revealed that the ligand acted as a neutral tridentate coordinating to the metal ion through ONO donor sequence. A coordination number nine was proposed for the complexes. Thermal decomposition studies of the ligand and lanthanum（Ⅲ） complex were carried out and kinetic parameters were calculated using Coats-Redfem equation. The decomposition reactions followed random nucleation mechanism with one nucleus on each particle.

关键词： lanthanides o-hydroxyacetophenone molar conductance magnetic susceptibility thermal study rare earths

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Comparative studies on Y(Ⅲ)and Dy(Ⅲ)extraction from hydrochloric and nitric acids by Cyanex 572 as a novel extractant

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Journal of Rare Earths 2018年第12期36卷 1342-1350页

作者： N.E.El-Hefny M.S.Gasser Sh.Sh.Emam W.H.Mahmoud H.F.Aly Hot Laboratories Centre Atomic Energy Authority Faculty of Science Ain Shams University

Extraction of Y(III) and Dy(III) from hydrochloric and nitric acids by Cy-572 in kerosene was studied. The factors affecting the extraction were separately investigated. The stoichiometry of the extracted species was deduced on the basis of slope analysis method. Evaluation of extraction equilibrium and stripping investigation was studied as well as saponification effect of Cy-572. The composition of the extracted metal species in the organic phase was found to be [MA·(HA)] for Y(III) or Dy(III) in both media.1.0 mol/L HCI is the best stripping agent for each metal ion from the studied acidic media in one *** Cy-572 does not exhibit any selectivity towards the extraction of Y(III) or Dy(III) from both HCI and HNOsolutions. Based on the obtained results, the data were compared and the separation feasibility between lanthanides and Y(III) in the two media was discussed.

关键词： Extraction Cyanex-572 Yttrium lanthanides Separation factor Saponification

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Fractionation of Rare Earth Elements in Plants Ⅰ. Fractionation Patterns and Their Forming Mechanisms in Different Organs of Triticum Aestivum

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Journal of Rare Earths 2005年第2期23卷 224-229页

作者：梁涛丁士明张朝生张自立阎军才李海涛 Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Department of Geography and Environmental Change Institute National University of Ireland Galway Ireland Department of Soil and Agrichemistry Anhui Agricultural University Hefei 230036China

Fractionations of rare earth elements (REEs) and the forming mechanisms in plants were studied using Triticum aestivum as plant material with application of exogenous REEs and hydroponic culture. REEs were significantly fractionated in different parts of Triticum aestivum. M-type tetrad effect could be observed in both root and shoot of Triticum aestivum, which might result from the different abilities of REEs to form phosphate precipitation. Middle REEs (MREEs), light REEs (LREEs) and heavy REEs (HREEs) were enriched in root, stem and leaf of Triticum aestivum, respectively. REE speciation calculations using VMINTEQ program show REEs in simulated xylem solution mainly exist as REE-EDTA^(- )and RE^(3+), but only HREEs are enriched in REE-EDTA^(-), while LREEs are enriched in the other REE species. It is suggested that the fractionation between LREEs and HREEs might be caused by the uptake of REE-EDTA^(-) in Triticum aestivum leaves, but might result from the uptake of the other REE species in their stems.

关键词： fractionation lanthanides tetrad effect Triticum aestivum rare earths

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