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Sample records for chiral lanthanide complexes

  1. Brilliant Sm, Eu, Tb and Dy chiral lanthanide complexes withstrong circularly polarized luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Petoud, Stephane; Muller, Gilles; Moore, Evan G.; Xu, Jide; Sokolnicki, Jurek; Riehl, James P.; Le, Uyen; Cohen, Seth M.; Raymond,Kenneth N.

    2006-07-10

    The synthesis, characterization and luminescent behavior of trivalent Sm, Eu, Dy and Tb complexes of two enantiomeric, octadentate, chiral, 2-hydroxyisophthalamide ligands are reported. These complexes are highly luminescent in solution. Functionalization of the achiral parent ligand with a chiral 1-phenylethylamine substituent on the open face of the complex in close proximity to the metal center yields complexes with strong circularly polarized luminescence (CPL) activity. This appears to be the first example of a system utilizing the same ligand architecture to sensitize four different lanthanide cations and display CPL activity. The luminescence dissymmetry factor, g{sub lum}, recorded for the Eu(III) complex is one of the highest values reported, and this is the first time the CPL effect has been demonstrated for a Sm(III) complex with a chiral ligand. The combination of high luminescence intensity with CPL activity should enable new bioanalytical applications of macromolecules in chiral environments.

  2. Stereochemistry and solid-state circular dichroism spectroscopy of eight-coordinate chiral lanthanide complexes

    Institute of Scientific and Technical Information of China (English)

    ZHOU Nan; WAN ShiGang; ZHAO Jian; LIN YiJi; XUAN WeiMin; FANG XueMing; ZHANG Hui

    2009-01-01

    Eight-coordinate chiral lanthanide complexes[Eu(dbm)_3L~(RR)](1),[Eu(dbm)_3L~(SS)](2) and[Tb(dbm)_3L~(RR)](3)(L~(RR)/L~(SS)=(-)-1(+)-4,5-pineno-2,2'-bipyridine,Hdbm=dibenzoylmethane) were synthesized stereoselectively,which were characterized by UV-vis,CD spectra and X-ray single-crystal diffraction.The mirrorimage structure features of complexes 1 and 2 were obtained by combination of the solid-state CD spectra and the crystal structure analysis.After further comparison with the solid-state CD spectra of six-coordinate and seven-coordinate metal complexes containing β-diketone ligands,the CD spectraabsolute configuration correlation rule for the eight-coordinate β-diketonate lanthanide complexes was proposed through the exciton chirality method for the first time.The △ or Λ absolute configurations of complexes 1-3 with the distorted square antiprism geometry were confirmed by the X-ray single-crystal analysis.

  3. Chiral mononuclear lanthanide complexes and the field-induced single-ion magnet behaviour of a Dy analogue.

    Science.gov (United States)

    Lin, Shuang-Yan; Wang, Chao; Zhao, Lang; Wu, Jianfeng; Tang, Jinkui

    2015-01-01

    Three pairs of homochiral mononuclear lanthanide complexes, with the general formula [LnH4LRRRRRR/SSSSSS(SCN)2](SCN)2·xCH3OH·yH2O(Ln = Dy (R/S-Dy1), Ho (R/S-Ho1) and Er (R/S-Er1)), have been obtained via self-assembly between chiral macrocyclic ligands and the respective thiocyanates, all of which show a saddle-type conformation with seven-coordinated metal ions. Magnetic measurements revealed that the Dy complex shows field-induced single-ion magnet behaviour, which is rarely reported in a seven-coordinated lanthanide-based SIM encapsulated in a macrocyclic ligand. The absolute configuration of all enantiomers was determined by single crystal X-ray crystallography and confirmed by electronic CD and VCD spectra. PMID:25369972

  4. Photocytotoxic lanthanide complexes

    Indian Academy of Sciences (India)

    Akhtar Hussain; Akhil R Chakravarty

    2012-11-01

    Lanthanide complexes have recently received considerable attention in the field of therapeutic and diagnostic medicines. Among many applications of lanthanides, gadolinium complexes are used as magnetic resonance imaging (MRI) contrast agents in clinical radiology and luminescent lanthanides for bioanalysis, imaging and sensing. The chemistry of photoactive lanthanide complexes showing biological applications is of recent origin. Photodynamic therapy (PDT) is a non-invasive treatment modality of cancer using a photosensitizer drug and light. This review primarily focuses on different aspects of the chemistry of lanthanide complexes showing photoactivated DNA cleavage activity and cytotoxicity in cancer cells. Macrocyclic texaphyrin-lanthanide complexes are known to show photocytotoxicity with the PDT effect in near-IR light. Very recently, non-macrocyclic lanthanide complexes are reported to show photocytotoxicity in cancer cells. Attempts have been made in this perspective article to review and highlight the photocytotoxic behaviour of various lanthanide complexes for their potential photochemotherapeutic applications.

  5. Lanthanide porphyrin complexes

    International Nuclear Information System (INIS)

    The review summarizes literature data and results of the author's research on the synthesis, properties and possible fields of practical application of lanthanide porphyrin complexes. Emphasis is given to the application of luminescence properties of lanthanide derivatives in medicine. The bibliography includes 108 references.

  6. Chiral recognition of proteins having L-histidine residues on the surface with lanthanide ion complex incorporated-molecularly imprinted fluorescent nanoparticles

    International Nuclear Information System (INIS)

    In this study, lanthanide ion complex incorporated molecularly imprinted fluorescent nanoparticles were synthesized. A combination of three novel approaches was applied for the purpose. First, lanthanide ions [Terbium(III)] were complexed with N-methacryloyl-L-histidine (MAH), polymerizable derivative of L-histidine amino acid, in order to incorporate the complex directly into the polymeric backbone. At the second stage, L-histidine molecules imprinted nanoparticles were utilized instead of whole protein imprinting in order to avoid whole drawbacks such as fragility, complexity, denaturation tendency, and conformation dependency. At the third stage following the first two steps mentioned above, imprinted L-histidine was coordinated with cupric ions [Cu(II)] to conduct the study under mild conditions. Then, molecularly imprinted fluorescent nanoparticles synthesized were used for L-histidine adsorption from aqueous solution to optimize conditions for adsorption and fluorimetric detection. Finally, usability of nanoparticles was investigated for chiral biorecognition using stereoisomer, D-histidine, racemic mixture, D,L-histidine, proteins with surface L-histidine residue, lysozyme, cytochrome C, or without ribonuclease A. The results revealed that the proposed polymerization strategy could make significant contribution to the solution of chronic problems of fluorescent component introduction into polymers. Additionally, the fluorescent nanoparticles reported here could be used for selective separation and fluorescent monitoring purposes. Highlights: • Lanthanide ion complex incorporated molecularly imprinted fluorescent nanoparticles • Direct incorporation of the fluorescent complex into polymeric backbone. • Imprinting by assistance of cupric ion coordination into nanoparticles • Evaluation of the chiral biorecognition ability of nanoparticles • Simultaneous selective separation and fluorescent monitoring

  7. Chiral recognition of proteins having L-histidine residues on the surface with lanthanide ion complex incorporated-molecularly imprinted fluorescent nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Uzun, Lokman, E-mail: lokman@hacettepe.edu.tr [Hacettepe University, Department of Chemistry, 06381, Ankara (Turkey); Uzek, Recep; Şenel, Serap [Hacettepe University, Department of Chemistry, 06381, Ankara (Turkey); Say, Ridvan [Anadolu University, Department of Chemistry, 26470, Eskisehir (Turkey); Denizli, Adil [Hacettepe University, Department of Chemistry, 06381, Ankara (Turkey)

    2013-08-01

    In this study, lanthanide ion complex incorporated molecularly imprinted fluorescent nanoparticles were synthesized. A combination of three novel approaches was applied for the purpose. First, lanthanide ions [Terbium(III)] were complexed with N-methacryloyl-L-histidine (MAH), polymerizable derivative of L-histidine amino acid, in order to incorporate the complex directly into the polymeric backbone. At the second stage, L-histidine molecules imprinted nanoparticles were utilized instead of whole protein imprinting in order to avoid whole drawbacks such as fragility, complexity, denaturation tendency, and conformation dependency. At the third stage following the first two steps mentioned above, imprinted L-histidine was coordinated with cupric ions [Cu(II)] to conduct the study under mild conditions. Then, molecularly imprinted fluorescent nanoparticles synthesized were used for L-histidine adsorption from aqueous solution to optimize conditions for adsorption and fluorimetric detection. Finally, usability of nanoparticles was investigated for chiral biorecognition using stereoisomer, D-histidine, racemic mixture, D,L-histidine, proteins with surface L-histidine residue, lysozyme, cytochrome C, or without ribonuclease A. The results revealed that the proposed polymerization strategy could make significant contribution to the solution of chronic problems of fluorescent component introduction into polymers. Additionally, the fluorescent nanoparticles reported here could be used for selective separation and fluorescent monitoring purposes. Highlights: • Lanthanide ion complex incorporated molecularly imprinted fluorescent nanoparticles • Direct incorporation of the fluorescent complex into polymeric backbone. • Imprinting by assistance of cupric ion coordination into nanoparticles • Evaluation of the chiral biorecognition ability of nanoparticles • Simultaneous selective separation and fluorescent monitoring.

  8. Luminescent macrocyclic lanthanide complexes

    Science.gov (United States)

    Raymond, Kenneth N.; Corneillie, Todd M.; Xu, Jide

    2012-05-08

    The present invention provides a novel class of macrocyclic compounds as well as complexes formed between a metal (e.g., lanthanide) ion and the compounds of the invention. Preferred complexes exhibit high stability as well as high quantum yields of lanthanide ion luminescence in aqueous media without the need for secondary activating agents. Preferred compounds incorporate hydroxy-isophthalamide moieties within their macrocyclic structure and are characterized by surprisingly low, non-specific binding to a variety of polypeptides such as antibodies and proteins as well as high kinetic stability. These characteristics distinguish them from known, open-structured ligands.

  9. Studies of lanthanide complexes by a combination of spectroscopic methods

    Czech Academy of Sciences Publication Activity Database

    Krupová, Monika; Bouř, Petr; Andrushchenko, Valery

    2015-01-01

    Roč. 22, č. 1 (2015), s. 44. ISSN 1211-5894. [Discussions in Structural Molecular Biology . Annual Meeting of the Czech Society for Structural Biology /13./. 19.03.2015-21.03.2015, Nové Hrady] Institutional support: RVO:61388963 Keywords : lanthanide complexes * chirality sensing * chirality amplification * spectroscopy Subject RIV: CF - Physical ; Theoretical Chemistry

  10. Aromatic triamide-lanthanide complexes

    Science.gov (United States)

    Raymond, Kenneth N; Petoud, Stephane; Xu, Jide

    2013-10-08

    The present invention provides luminescent lanthanide metal chelates comprising a metal ion of the lanthanide series and a complexing agent comprising at least one phthalamidyl moiety. Also provided are probes incorporating the phthalamidyl ligands of the invention and methods utilizing the ligands of the invention and probes comprising the ligands of the invention.

  11. Understanding complex chiral plasmonics

    Science.gov (United States)

    Duan, Xiaoyang; Yue, Song; Liu, Na

    2015-10-01

    Chiral nanoplasmonics exhibits great potential for novel nanooptical devices due to the generation of a strong chiroptical response within nanoscale metallic structures. Recently, a number of different approaches have been utilized to create chiral nanoplasmonic structures. However, particularly for tailoring nanooptical chiral sensing devices, the understanding of the resulting chiroptical response when coupling chiral and achiral structures together is crucial and has not been completely understood to date. Here, we present a thorough and step-by-step experimental study to understand the intriguing chiral-achiral coupling scheme. We set up a hybrid plasmonic system, which bears resemblance to the `host-guest' system in supramolecular chemistry to analyze and explain the complex chiral response both at the chiral and achiral plasmonic resonances. We also provide an elegant and simple analytical model, which can describe, predict, and comprehend the chiroptical spectra in detail. Our study will shed light on designing well-controlled chiral-achiral coupling platforms for reliable chiral sensing.Chiral nanoplasmonics exhibits great potential for novel nanooptical devices due to the generation of a strong chiroptical response within nanoscale metallic structures. Recently, a number of different approaches have been utilized to create chiral nanoplasmonic structures. However, particularly for tailoring nanooptical chiral sensing devices, the understanding of the resulting chiroptical response when coupling chiral and achiral structures together is crucial and has not been completely understood to date. Here, we present a thorough and step-by-step experimental study to understand the intriguing chiral-achiral coupling scheme. We set up a hybrid plasmonic system, which bears resemblance to the `host-guest' system in supramolecular chemistry to analyze and explain the complex chiral response both at the chiral and achiral plasmonic resonances. We also provide an elegant

  12. Recent Advances in Organic Reactions Catalyzed by Lanthanide (Ⅲ) Complexes

    Institute of Scientific and Technical Information of China (English)

    CHEN,Rui-Fang(陈瑞芳); QIAN,Chang-Tao(钱长涛)

    2002-01-01

    Lanthanide compounds have been attracting much attention in organic synthesis. Chiral Ln-substituted BINOL have been widely studied in several asymmetric organic reactions. LnCl3 and Ln(OTf)3 have been expected to serve as Lewis acids and have been applied to many important synthetic reactions in a one-pot manner. Ln(O-i-Pr)3 exhibits some basic characters,which also can be utilized in some special organic transformation. This article deals with some lanthanides (Ⅲ) complexes promoted organic reactions, which we have recently developed.

  13. Pyridinophane platform for stable lanthanide(III) complexation.

    Science.gov (United States)

    Castro, Goretti; Bastida, Rufina; Macías, Alejandro; Pérez-Lourido, Paulo; Platas-Iglesias, Carlos; Valencia, Laura

    2013-05-20

    A detailed investigation of the solid state and solution structures of lanthanide(III) complexes with the macrocyclic ligand 2,11,20-triaza[3.3.3](2,6)pyridinophane (TPP) is reported. The solid state structures of 14 different Ln(3+) complexes have been determined using X-ray crystallography. The ligand is coordinating to the Ln(3+) ion by using its six nitrogen atoms, while nitrate or triflate anions and water molecules complete the metal coordination environments. The structure of the complexes in solution has been investigated by (1)H and (13)C NMR spectroscopy, as well as by DFT calculations (TPSSh model) performed in aqueous solution. The structures obtained from these calculations for the complexes with the lightest Ln(3+) ions (La-Sm) are in very good agreement with those determined by the analysis of the Ln(3+)-induced paramagnetic shifts. A structural change occurs across the lanthanide series at Sm(3+); the complexes of the large Ln(3+) ions (La-Nd) are chiral due to the nonplanar conformation of the macrocycle, and present effective C3v symmetries in solution as a consequence of a fast interconversion of two enantiomeric forms with C3 symmetry. The activation free energy for this enantiomerization process, as estimated by using DFT calculations, amounts to 33.0 kJ·mol(-1). The TPP ligand in the complexes of the heaviest Ln(3+) ions (Eu-Lu) presents a half-chair conformation, which results in C(s) symmetries in solution. PMID:23627284

  14. Studies of some lanthanide quaternary complexes

    International Nuclear Information System (INIS)

    Formation constants of mixed ligand quaternary lanthanide complexes of the type M-A-B-L'/L' where M=La3+, Pr3+, Nd3+; A=ethylenediamine N, N, N', N'-tetraacetic acid (EDTA); B=thiodiglycolic acid (TDA); L'=iminodiacetic acid (IDA) and L'=glycine (GLY) have been determined by pH-metric technique at 35±1degC in 0.1 mol dm-3KNO3. Stability constants reveal the orders: La(III)< Pr(III)< Nd(III) in terms of metal ions, binary< ternary< quaternary in terms of complex species, and IDA< Gly in terms of amino acids. The Δ LOG K values are negative for all the ternary and quaternary systems. However, Δ log K values are significantly positive indicating intramolecular hydrophobic ligand-ligand interactions. (author). 16 refs

  15. Phthalamide-lanthanide complexes for use as luminescent markers

    Science.gov (United States)

    Raymond, Kenneth N.; Petoud, Stephane; Cohen, Seth; Xu, Jide

    2008-10-28

    The present invention provides luminescent lanthanide metal chelates comprising a metal ion of the lanthanide series and a complexing agent comprising at least one phthalamidyl moiety. Also provided are probes incorporating the phthalamidyl ligands of the invention and methods utilizing the ligands of the invention and probes comprising the ligands of the invention.

  16. Fluorescence of lanthanide(III) complexes in aqueous solutions

    International Nuclear Information System (INIS)

    The fluorescence of lanthanide ions and of their complexes with EDTA, NTA and AA in aqueous solutions was investigated. It has been shown that the fluorescence band intensities of Sm(III), Eu(III), Gd(III), Tb(III) and Dy(III) complexes depend on the pH and the complexing agent concentration. Fluorescence measurements were used to characterise the lanthanide complexes formed and an attempt was made to interpret the results theoretically. (Author)

  17. Lanthanide (III) complexes of 2-(N-salicylideneamino)-4-phenylthiazole

    International Nuclear Information System (INIS)

    Lanthanide(III) complexes of 2-(N-salicylideneamino)-4- phenylthiazole (HSAT) have been synthesised and characterised by elemental, analytical, thermogravimetric, molar conductance, UV- visible, IR and NMR spectral data. The ligand coordinates to the lanthanide(III) ion in a tridentate fashion without deprotonation, giving complexes of the type [Ln(HSAT)2(NO3)3] and [Ln(HSAT)2(H20)3Cl3]. The spectral data reveal that the ligand is bonded to the lanthanide ion through azomethine nitrogen, ring nitrogen and phenolic oxygen without deprotonation. The nitrate group acts in a bidentate fashion. The ligand and the metal complexes exhibit antibacterial and antifungal activities. (author)

  18. Lanthanide ion complexes of calixarenes. Pt. VII

    International Nuclear Information System (INIS)

    Reaction of Ln(ClO4)3.xdmso (dmso denotes dimethyl sulfoxide) with a warm p-t-butylcalix[8]arene (L) slurry in acetone/dmso yields crystalline 2:1 Ln/ligand adducts, characterized as dmso solvates and established to be [Ln2(L-6H)(dmso)5].∼2dmso by single-crystal X-ray studies at c. 295 K for Ln = La, Eu, Tm and Lu. All complexes are isomorphous, orthorhombic with a similar complex molecule in each case, one half comprising the asymmetric unit; the second half is generated by a crystallographic twofold axis. The two lanthanide atoms are encompassed by the macrocycle and are eight coordinate, involving phenolic and dmso O-donor atoms, five of the former (two bridging) and three of the latter (one bridging). The array closely resembles that found in analogous dmf solvent adducts: the bridging dmso lies on the crystallographic twofold axis through the complex, its peripheral atoms being modelled by disorder. 25 refs., 3 tabs., 1 fig

  19. Lanthanide Ternary Complexes Relevent to the Nuclear Fuel Cycle

    OpenAIRE

    Roughley, Georgina

    2012-01-01

    This project has been focused on modelling actinide behaviour using lanthanide analogues. Ternary complexes of Lanthanides-EDTA-Carbonate have been studied with techniques such as potentiometry and ultraviolet-visible absorption spectroscopy.It was found that ternary complexes of Ln-EDTA-Carbonate and Ln-EDTA-OH do exist for La, Eu and Lu. Log K values were calculated from potentiometry titrations which involve the formation of these ternary species. For lanthanum, the log K values for the co...

  20. The complexation of lanthanides by azo-. beta. -diketones stability constants

    Energy Technology Data Exchange (ETDEWEB)

    Zabra, A.M.; Ramadian, A.A.I.; El-Shetary, B.A.; Abdel-Moez, M.S.

    1982-03-01

    In the present investigation the overall stability constants of an interest tridentate organic ligands and tervalent lanthanide ions have been measured potentiometrically. The stability constants of the complexes between the trivalent lanthanide series of cations and series of azo-..beta..-diketone ligands are reported. The measurements were conducted at 30/sup 0/ at an ionic strength of zero, in 100% methanol. The relation between the overall stability constant (log ..beta../sub 2/) and atomic number of the lanthanide elements, shows a buffer zone at the gadolinium area. The relation between (log ..beta../sub 2/) and the basicity of the studied ligands (..sigma..pK's) are also, discussed. The overall stability values obtained reflected a great affinity of the organic ligands for chelation with lanthanide ions.

  1. Determination of stability constants of lanthanide complexes with tetracycline

    International Nuclear Information System (INIS)

    The stability constants of complexes compounds formed with tetracycline and lanthanides elements were determined for all lanthanides except promethium. The experimental procedure used was solvent extraction of the lanthanides labelled with their radioactive isotopes. It was shown that the formed complexes are mononuclear and that no hydroxo complexes or negatively charged complexes are formed in the experimental conditions of this work. Four methods of calculation were used for all complexes studied: the method of the average number of ligands, the method of limiting value, the method of two parameters and the method of weighted least squares. A comparison was made of the graphical methods with the method of least squares, showing the convenience of preceding least squares calculation by the graphical methods, in order to verify eventual mistakes of numerical data. It was shown the advantage of using radioisotopes of the elements for such a study, specially if the solvent extraction technique is used to-get the experimental data. (author)

  2. Lanthanide carbonate-phosphate complexes of different ligands

    International Nuclear Information System (INIS)

    Previously undescribed carbonate-phosphate complexes of lanthanides (Ln) have been derived. Their optical and luminescent properties have been stUdied. It is shown that the lanthanide ions may form in solutions highly charged anions preferably corresponding to formulas: [NdCO3(PO4)3]8-, [HoCO3(PO4)3]8- and [Er(CO3)2(PO4)]10-. The stability constants (Ksub(st)) of the resulting heteroligand complexes have been determined. A new version of the luminescent method of determining the composition of carbonate-phosphate complexes of Eu is suggested

  3. Lanthanide-cored fluorinated dendrimer complexes: synthesis and luminescence characterization

    International Nuclear Information System (INIS)

    Eu3+-, Tb3+- and Er3+-cored dendrimer complexes were prepared by self-assembly of three fluorinated dendrons, each with a carboxylate anion focal point, around the lanthanide ion. Energy transfer from the peripheral fluorinated phenyl moieties of the dendrons to the lanthanide cation was evidenced spectroscopically for Eu3+- and Tb3+-cored dendrimer complexes in solution. The excitation of perfluorinated aromatic groups was found to decay with ca. 0.7 ns and a longer decay time 10-13 ns was related to the coordination at the Ln3+ focal point. Luminescence from the lanthanide core decays with lifetime in the range 1-1.5 ms over a wide concentration range (μM-mM), similar to the luminescence decay time of the corresponding acetate ion complexes in D2O. The main quenching mechanism of the lanthanide emission appears to be due to vibrations among surrounding C-H bonds of the intermediate shell of the flexible dendrimer scaffold. Antenna effect and energy harvesting from the surface of the dendrimer and transfer to the core was the main mechanism for luminescecnce in the dendrimer complexes with lanthanide cations

  4. Lanthanide and actinide complexation studies with tetradentate 'N' donor ligands

    International Nuclear Information System (INIS)

    Because of their similar charge and chemical behaviour separation of trivalent actinides and lanthanides is an important and challenging task in nuclear fuel cycle. Soft (S,N) donor ligands show selectivity towards the trivalent actinides over the lanthanides. Out of various 'N' donor ligands studied, bis(1,2,4)triazinyl bipyridine (BTBP) and bis(1,2,4)triazinyl phenanthroline (BTPhen) were found to be most promising. In order to understand the separation behaviour of these ligands, their complexation studies with these 'f' block elements are essential. In the present work, complexation studies of various lanthanide ions (La3+, Eu3+ and Er3+) was studied with ethyl derivatives of BTBP (C2BTBP) and BTBPhen (C2BTPhen) and pentyl derivative of BTBP (C5BTBP) in acetonitrile medium using UV-Vis spectrophotometry, fluorescence spectroscopy and solution calorimetry. Computational studies were also carried out to understand the experimental results

  5. Exploring the effect of remote substituents and solution structure on the luminescence of three lanthanide complexes

    International Nuclear Information System (INIS)

    Sensitized luminescence from trivalent lanthanide ions relies on an appropriate energy match between the sensitizer’s excited state (triplet or singlet) and the lanthanide excited state manifold, and also an efficient mechanism of energy transfer between the two. Here, the effect of remote substituents on the luminescence properties of a series of related lanthanide complexes has been investigated. The sensitized lanthanide centered emission is not invariably found to occur following excitation of all chromophores in all systems, and it is shown that only the most structurally congested of the systems investigated exhibited pronounced solvatochromism. - Highlights: • Effect of remote substituents and self-assembly on lanthanide luminescence. • Molecular structure rather than chromophore density defines lanthanide sensitization. • Kimura's and Horrocks' approach to determine lanthanide solvation is revisited. • Solvent alters sensitization pathways in multinuclear lanthanide complexes. • Increasing chromophore density may reduce lanthanide luminescence

  6. Far-infrared spectra of lanthanide complexes with 8-hydroxyquinoline

    International Nuclear Information System (INIS)

    Vibrational spectra of lanthanide oxines have been measured in the far-infrared region. In addition, the similar yttrium complex was investigated for further experimental evidence for the proposed band assignments. The most important metal-oxygen and metal-nitrogen bond vibrations have been attributed to absorptions between 390-350cm-1 and 210-170cm-1, respectively. (Author)

  7. Calorimetric approach of lanthanides (3) complexation and extraction by malonamides

    International Nuclear Information System (INIS)

    In the field of long lived radionuclides separation, diamides are interesting extractants because of their ability to co-extract trivalent lanthanides and actinides, which is a preliminary and essential step in high level radioactive waste reprocessing. The research carried out contributes to a better understanding of the mechanisms and the aim is the determination of thermodynamics properties (ΔrG, ΔrH et ΔrS) related to the complexation and the extraction of lanthanides(III) by malonamides. The first part of the document deals with the complexation of lanthanides(III) by an hydrosoluble diamide. The experimental results obtained by UV-visible spectrometry, TRLIF, NMR and microcalorimetric titration proved that lanthanides(III)-TEMA interactions in aqueous medium are very weak and that the complexation reaction is endothermic. The TEMA ligand still stays in the second coordination sphere of coordination of the lanthanide ion. The second part of this study focuses on the extraction of neodymium(III) nitrate by a lipophilic diamide which is an exothermic reaction. The influence of the composition of aqueous and organic phases on the thermodynamics properties ΔrG et ΔrH has been studied by microcalorimetric titration. The most influent parameter is the total concentration in extractant. As a consequence, thermodynamic values are very dependent on the organic phase organisation before and alter extraction. At the same time, this study showed the interest of the calorimetric approach for the analysis of basic reactions like diamide dilution and their organisation as oligomeric aggregates. (author)

  8. Polarized luminescence from aligned samples of nematogenic lanthanide complexes

    OpenAIRE

    Galyametdinov, Yury G.; Knyazev, Andrey A.; Dzhabarov, Vagif I.; Cardinaels, Thomas; Driesen, Kris; Görller-Walrand, Christiane; Binnemans, Koen

    2008-01-01

    The first examples of lanthanidomesogens that exhibit a low viscous nematic phase are presented. The compounds are one of the rare examples of liquid-crystalline lanthanide complexes that show polymorphism in the mesophase region (smectic A and nematic phases). The temperatures at which the nematic phase occurs are low and the nematic temperature range is broad, which makes these materials interesting for further physical studies. Moreover, the compounds are thermally stable. It is illustrate...

  9. Some lanthanide complexes of semicarbazone and thiosemicarbazone derived from fluorenone

    International Nuclear Information System (INIS)

    A new series of lanthanide chloride complexes with the ligands fluorenone semicarbazone (FSC) and fluorenone thiosemicarbazone (FTSC) of composition [LnLCl2(H2O)2](Ln = La, Pr, Nd, Sm, Gd) were synthesised and characterized by microanalytical, spectral, magnetic and conductivity data. These ligands act as monovalent bidentate and bond through carbonyl oxygen/thiocarbonyl sulfur and the azomethine nitrogen atom. (author). 18 refs., 2 tabs

  10. Synthesis and characterization of lanthanide picrate complexes with 4-picoline-N-oxide (4-pic N O)

    International Nuclear Information System (INIS)

    The lanthanide picrate complexes with 4-picoline-N-oxide were obtained from ethanolic solutions of the hydrated lanthanide picrate and the ligand. The lanthanide content was determined by complexometric titration with EDTA. Carbon, Nitrogen and Hydrogen were determined by microanalytical procedures. Chemical analysis of the lanthanide picrate complexes are also presented. (author)

  11. Asymmetric Catalytic Reactions Catalyzed by Chiral Titanium Complexes

    Institute of Scientific and Technical Information of China (English)

    FENG; XiaoMing

    2001-01-01

    Chiral titanium complexes is very importance catalyst to asymmetric catalytic reactions. A series of catalytic systems based on titanium-chiral ligands complexes has been reported. This presentation will discuss some of our recent progress on asymmetric catalytic reactions catalyzed by chiral titanium complexes.  ……

  12. Asymmetric Catalytic Reactions Catalyzed by Chiral Titanium Complexes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Chiral titanium complexes is very importance catalyst to asymmetric catalytic reactions. A series of catalytic systems based on titanium-chiral ligands complexes has been reported. This presentation will discuss some of our recent progress on asymmetric catalytic reactions catalyzed by chiral titanium complexes.

  13. Energetic lanthanide complexes: coordination chemistry and explosives applications

    International Nuclear Information System (INIS)

    Metals are generally added to organic molecular explosives in a heterogeneous composite to improve overall heat and energy release. In order to avoid creating a mixture that can vary in homogeneity, energetic organic molecules can be directly bonded to high molecular weight metals, forming a single metal complex with Angstrom-scale separation between the metal and the explosive. To probe the relationship between the structural properties of metal complexes and explosive performance, a new series of energetic lanthanide complexes has been prepared using energetic ligands such as NTO (5-nitro-2,4-dihydro-1,2,4-triazole-3-one). These are the first examples of lanthanide NTO complexes where no water is coordinated to the metal, demonstrating novel control of the coordination environment. The complexes have been characterized by X-ray crystallography, NMR and IR spectroscopies, photoluminescence, and sensitivity testing. The structural and energetic properties are discussed in the context of enhanced blast effects and detection. Cheetah calculations have been performed to fine-tune physical properties, creating a systematic method for producing explosives with 'tailor made' characteristics. These new complexes will be benchmarks for further study in the field of metalized high explosives.

  14. Structural rearrangement through lanthanide contraction in dinuclear complexes.

    Science.gov (United States)

    Hutchings, Amy-Jayne; Habib, Fatemah; Holmberg, Rebecca J; Korobkov, Ilia; Murugesu, Muralee

    2014-02-17

    A new series of lanthanide complexes was synthesized, and the geometry and preliminary magnetic measurements of the complexes were explored. The specific ligand used (N'-(2-hydroxy-3-methoxybenzylidene)benzhydrazide) (H2hmb) was synthesized using a Schiff-base approach and was employed due to the presence of a coordination pocket that is able to accommodate magnetically selective lanthanide ions. The series can be divided into two groups that are categorized by a drastic structural rearrangement. The first group, Type I, contains six analogous complexes with the formula [M(III)2(Hhmb)3(NCS)3]·2MeOH·py (M = Y 1, Eu 2, Gd 3, Tb 4, Dy 5, Ho 6), while the second group, Type II, contains two dinuclear complexes with formula [M(III)2(Hhmb)2(NCS)4(MeOH)2] (M = Er 7, and Yb 8). Single-crystal X-ray analysis revealed that all M(III) ions in Type I exhibit monocapped distorted square antiprismatic geometries, while those of Type II exhibit distorted dodecahedron geometry. The direct current and alternating current magnetic measurements were carried out on all complexes, with 5, 7, and 8 exhibiting slow relaxation of the magnetization under an applied optimum dc field. Furthermore, complex 8 is the first example of a dinuclear Yb-based single-molecule magnet showing field-dependent multiple relaxation processes. PMID:24499030

  15. Chiral (6,3) Network Assembled by Lanthanide and Changeful Dihydroxyfumaric Acid%Chiral (6,3) Network Assembled by Lanthanide and Changeful Dihydroxyfumaric Acid

    Institute of Scientific and Technical Information of China (English)

    Zhang, Manbo; Lu, Jing; Hu, Ruixiang

    2012-01-01

    A series of chiral two-dimensional lanthanide coordination polymers, [Ln2(L)3(H2O)6]n·n/3H2O[Ln=Nd (la, lb), Sm (2), Eu (3), Tb (4), Dy (5), Ho (6), Er (7); H2L=2,2-dihydroxylmalonic acid], have been hydrothermally synthesized by using dihydroxyfumaric acid as a source of polydentate O-donor ligands. The luminescence behav- iors of 3 and 4 have been investigated, and they exhibit strong red and green fluorescence in the visible region respectively.

  16. Magnetic Circular Dichroism of Porphyrin Lanthanide M3+ Complexes

    Czech Academy of Sciences Publication Activity Database

    Andrushchenko, Valery; Padula, Daniele; Zhivotova, E.; Yamamoto, S.; Bouř, Petr

    2014-01-01

    Roč. 26, č. 10 (2014), s. 655-662. ISSN 0899-0042 R&D Projects: GA ČR GA13-03978S; GA ČR GAP208/11/0105; GA MŠk(CZ) LH11033 Grant ostatní: GA AV ČR(CZ) M200550902 Institutional support: RVO:61388963 Keywords : magnetic circular dichroism * lanthanides * porphyrin complexes * density functional theory * sum over state computations Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.886, year: 2014

  17. Pico- and subpicosecond relaxation processes in lanthanide-porphyrin complexes

    International Nuclear Information System (INIS)

    Methods of nano- and picosecond absorption spectroscopy and luminescence are used to determine the deactivation rates of π, π*-electron states of S2, S1 and T1 in complexes of organic molecules of meso-tetratolylporphyne and tetrabenzoporphyne with trivalent Sm3+, Eu3+, Gd3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, Yb3+, Lu3+. Quantitative data on superfast relaxation processes in lanthanide porphynes are obtained. The function of the metal entral ion is presented in details as the excitation factor in deactivation processes of photoexcitation energy of the systems in question

  18. Photo-reactive charge trapping memory based on lanthanide complex

    OpenAIRE

    Jiaqing Zhuang; Wai-Sum Lo; Li Zhou; Qi-Jun Sun; Chi-Fai Chan; Ye Zhou; Su-Ting Han; Yan Yan; Wing-Tak Wong; Ka-Leung Wong; V. A. L. Roy

    2015-01-01

    Traditional utilization of photo-induced excitons is popularly but restricted in the fields of photovoltaic devices as well as photodetectors, and efforts on broadening its function have always been attempted. However, rare reports are available on organic field effect transistor (OFET) memory employing photo-induced charges. Here, we demonstrate an OFET memory containing a novel organic lanthanide complex Eu(tta)3ppta (Eu(tta)3 = Europium(III) thenoyltrifluoroacetonate, ppta = 2-phenyl-4,6-b...

  19. Synthesis of Resins with Chiral Salen Complexes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ The enormous growth in the use of polymer resin supports in solid phase combinatorial synthesis, and related methodologies, has re-stimulated interest in the area of polymer-supported transition metal complex catalyst .The recently developed chiral salen-based for the enantioselective ring opening of meso epoxides and kinetic resolution of terminal epoxides are appealing candidates for immobilization on solid support. The catalysts are reading prepare from inexpensive components, and are amenable to modification for attachment to a solid support.

  20. Photodegradation of a polypropylene filled with lanthanide complexes

    Directory of Open Access Journals (Sweden)

    Valérie Massardier

    2015-01-01

    Full Text Available Abstract This research aims at studying the photodegradation of a polypropylene formulation filled with lanthanide complexes. These complexes can be used as tracers for the identification of polymer materials in order to facilitate an high speed automatic sorting of plastic wastes for an economically efficient recycling. By paying attention to the evolution of carbonyl absorption bands in FTIR spectra, it is observed that the addition of lanthanide complexes into our formulation improves UV stability of polypropylene by reducing the extent of photo-degradation. Furthermore, TG analyses show that the traced blends can maintain better thermal properties, after irradiation. A significant increase of the crystallinity degree and a decrease of the melting temperature are more pronounced for the unfilled UV–irradiated PP. This might result from chemi-crystallization that can occur when chain entanglements are broken as a result of chain scissions. From SEM analyses, it is observed that the severity of surface cracks induced by photo degradation is reduced for filled PP. The mechanical tests are in agreement with this result and show a fundamental change in the behavior of the as-exposed blends from a ductile to a brittle material.

  1. Complexation of lanthanides and actinides with humic acids. Appendix II

    International Nuclear Information System (INIS)

    Natural waters are the main transport medium for radionuclides in the geosphere in case of an accidental release of radioactivity from a nuclear waste disposal. Complexation studies of radionuclides with natural organic substances present in aquifers are important to perform in order to predict their behaviour in natural systems. Interactions of two trivalent elements, curium and dysprosium, representative respectively for actinides and lanthanides, have been investigated by Time-Resolved Laser-Induced Spectrofluorometry (TRLIS) allowing to work at low concentrations of cations (10-6 M-10-8 M). By using a 'Fluorescence titration' method, complexing capacities and interaction constants are obtained over a broad pH range (4 to 7) at a constant ionic strength (0.1 M). The complexing behaviour of Cm and Dy is analysed. Data are discussed and compared with existing literature data. (orig.)

  2. Lanthanide humic substances complexation. I. Experimental evidence for a lanthanide contraction effect

    Science.gov (United States)

    Sonke, Jeroen E.; Salters, Vincent J. M.

    2006-03-01

    The interaction of the lanthanides (Ln) with humic substances (HS) was investigated with a novel chemical speciation tool, Capillary Electrophoresis-Inductively Coupled Plasma Mass Spectrometry (CE-ICP-MS). By using an EDTA-ligand competition method, a bi-modal species distribution of LnEDTA and LnHS is attained, separated by CE, and detected online by sector field ICP-MS. We quantified the binding of all 14 rare earth elements (REEs), Sc and Y with Suwannee river fulvic acid, Leonardite coal humic acid, and Elliot soil humic acid under environmental conditions (pH 6-9, 0.001-0.1 mol L -1 NaNO 3, 1-1000 nmol L -1 Ln, 10-20 mg L -1 HS). Conditional binding constants for REE-HS interaction ( Kc) ranged from 8.9 acids, we suggest that HS form a range of tri- to tetra-dentate complexes under environmental conditions. These results confirm HS to be a strong complexing agent for Ln, and show rigorous experimental evidence for potential REE fractionation by HS complexation.

  3. Studies on mixed ligand complexes of lanthanide (III) ions

    International Nuclear Information System (INIS)

    As part of our research programme, we have prepared and characterized a few nitrato, thiocyanato and perchlorato complexes of lanthanide(III) ions with ligands, viz., a Schiff base derived from p-anisidine and vanillin and diphenyl sulphoxide. The complexes were characterized by the measurement of electrical conductances and magnetic susceptibilities, molecular mass and metal percentage and spectral analysis. The thermal decompositions were studied by TG and DTG techniques. The thiocyanato complexes were prepared by substitution method from nitrato complexes. p-Anisidine-vanillin (HDDA) and diphenyl sulphoxide (DPSO) are coordinated to the metal ion in unidentate fashion. All the anions were involved in coordination in these complexes. Thus they were found to have non- electrolytic behaviour with composition [Ln(HDDA)2 (DPSO)X3] where X = NO3) or SCN perchlorato complexes were prepared from metal perchlorate as done in the case of nitrato complexes. They were found to have electrical conductance which corresponds to 1 : 1 electrolyte. Hence one of the perchlorate ions is outside the coordination sphere. The composition of this complex is found to be [Ln(HDDA)3(DPSO)(ClO4)2]ClO4. (author)

  4. Coordination symmetry determination of some lanthanide complexes by x-ray diffraction

    International Nuclear Information System (INIS)

    The x-ray determination of the crystal and molecular structures of three lanthanide complexes is described. The work is a contribution to the study of the coordination chemistry of lanthanide ions with organic ligands and in particular, it aims to compare the observed point symmetry of the ion environment with spectroscopic predictions. (author)

  5. Separation of americium(III) from lanthanides(III) by nanofiltration-complexation in aqueous medium

    International Nuclear Information System (INIS)

    The separation of Am(III) from a mixture of lanthanides(III) was performed in aqueous medium by nanofiltration combined with a complexation step using a DTPA derivative as selective complexing agent. (author)

  6. An enantiomerically pure siderophore type ligand for the diastereoselective 1 : 1 complexation of lanthanide(III ions

    Directory of Open Access Journals (Sweden)

    Markus Albrecht

    2009-12-01

    Full Text Available A facile synthesis of a highly preorganized tripodal enterobactine-type ligand 1a-H3 consisting of a chiral C3-symmetric macrocyclic peptide and three tridentate 2-amido-8-hydroxyquinoline coordinating units is presented. Complex formation with various metal ions (Al3+, Ga3+, Fe3+, La3+ and Eu3+ was investigated by spectrophotometric methods. Only in the case of La3+ and Eu3+ were well defined 1 : 1 complexes formed. On the basis of CD spectroscopy and DFT calculations the configuration at the metal centre of the La3+ complex was determined to show Λ helicity. The coordination compounds [(1aLn] presented should be prototypes for further lanthanide(III complexes with an enterobactine analogue binding situation.

  7. Highly Luminescent Lanthanide Complexes of 1 Hydroxy-2-pyridinones

    Energy Technology Data Exchange (ETDEWEB)

    University of California, Berkeley; Lawrence National Laboratory; Raymond, Kenneth; Moore, Evan G.; Xu, Jide; Jocher, Christoph J.; Castro-Rodriguez, Ingrid; Raymond, Kenneth N.

    2007-11-01

    The synthesis, X-ray structure, stability, and photophysical properties of several trivalent lanthanide complexes formed from two differing bis-bidentate ligands incorporating either alkyl or alkyl ether linkages and featuring the 1-hydroxy-2-pyridinone (1,2-HOPO) chelate group in complex with Eu(III), Sm(III) and Gd(III) are reported. The Eu(III) complexes are among some of the best examples, pairing highly efficient emission ({Phi}{sub tot}{sup Eu} {approx} 21.5%) with high stability (pEu {approx} 18.6) in aqueous solution, and are excellent candidates for use in biological assays. A comparison of the observed behavior of the complexes with differing backbone linkages shows remarkable similarities, both in stability and photophysical properties. Low temperature photophysical measurements for a Gd(III) complex were also used to gain insight into the electronic structure, and were found to agree with corresponding TD-DFT calculations for a model complex. A comparison of the high resolution Eu(III) emission spectra in solution and from single crystals also revealed a more symmetric coordination geometry about the metal ion in solution due to dynamic rotation of the observed solid state structure.

  8. Effect of applied hydrostatic pressure on the quenching kinetics, and electronic and molecular structure of eight and nine-coordinate lanthanide complexes in solution

    International Nuclear Information System (INIS)

    Full text: Applied hydrostatic pressure may be used as a probe of the reaction mechanism for various solution reactions involving lanthanide ions. In this work we report on the use of high pressure to probe the mechanism of enantioselective quenching between racemic luminescent lanthanide complexes containing Dy(III) Tb(III) and Eu(III), and optically active transition metal complexes as quenchers. Diastereomeric rate constants are obtained from a biexponential fit of the luminescence decay. Particular attention will be given to solvation effects on the measured diastereomeric rate constants. The source of chirality is ascribed to a enantioselective rearrangement step within a bimolecular 'encounter' complex yielding a intermolecular geometry in which the energy transfer is efficient. The effect of high pressure on the molecular and electronic structure of these complexes will also be discussed

  9. Fluoride Binding and Crystal-Field Analysis of Lanthanide Complexes of Tetrapicolyl-Appended Cyclen.

    Science.gov (United States)

    Blackburn, Octavia A; Kenwright, Alan M; Jupp, Andrew R; Goicoechea, Jose M; Beer, Paul D; Faulkner, Stephen

    2016-06-20

    Lanthanide complexes of tetrapicolyl cyclen displayed remarkably high affinities for fluoride (log K≈5) in water, and were shown to form 1:1 complexes. The behaviour of these systems can be rationalised by changes to the magnitude of the crystal-field parameter, B20 . However, such changes are not invariably accompanied by a change in sign of this parameter: for early lanthanides, the N8 donor set with a coordinated axial water molecule ensures that the magnetic anisotropy has the opposite sense to that observed in the analogous dehydrated lanthanide complexes. PMID:27167830

  10. VCD Studies on Chiral Characters of Metal Complex Oligomers

    Directory of Open Access Journals (Sweden)

    Hisako Sato

    2013-01-01

    Full Text Available The present article reviews the results on the application of vibrational circular dichroism (VCD spectroscopy to the study of stereochemical properties of chiral metal complexes in solution. The chiral characters reflecting on the vibrational properties of metal complexes are revealed by measurements of a series of β-diketonato complexes with the help of theoretical calculation. Attention is paid to the effects of electronic properties of a central metal ion on vibrational energy levels or low-lying electronic states. The investigation is further extended to the oligomers of β-diketonato complex units. The induction of chiral structures is confirmed by the VCD spectra when chiral inert moieties are connected with labile metal ions. These results have demonstrated how VCD spectroscopy is efficient in revealing the static and dynamic properties of mononuclear and multinuclear chiral metal complexes, which are difficult to clarify by means of other spectroscopes.

  11. Photo-reactive charge trapping memory based on lanthanide complex

    Science.gov (United States)

    Zhuang, Jiaqing; Lo, Wai-Sum; Zhou, Li; Sun, Qi-Jun; Chan, Chi-Fai; Zhou, Ye; Han, Su-Ting; Yan, Yan; Wong, Wing-Tak; Wong, Ka-Leung; Roy, V. A. L.

    2015-10-01

    Traditional utilization of photo-induced excitons is popularly but restricted in the fields of photovoltaic devices as well as photodetectors, and efforts on broadening its function have always been attempted. However, rare reports are available on organic field effect transistor (OFET) memory employing photo-induced charges. Here, we demonstrate an OFET memory containing a novel organic lanthanide complex Eu(tta)3ppta (Eu(tta)3 = Europium(III) thenoyltrifluoroacetonate, ppta = 2-phenyl-4,6-bis(pyrazol-1-yl)-1,3,5-triazine), in which the photo-induced charges can be successfully trapped and detrapped. The luminescent complex emits intense red emission upon ultraviolet (UV) light excitation and serves as a trapping element of holes injected from the pentacene semiconductor layer. Memory window can be significantly enlarged by light-assisted programming and erasing procedures, during which the photo-induced excitons in the semiconductor layer are separated by voltage bias. The enhancement of memory window is attributed to the increasing number of photo-induced excitons by the UV light. The charges are stored in this luminescent complex for at least 104 s after withdrawing voltage bias. The present study on photo-assisted novel memory may motivate the research on a new type of light tunable charge trapping photo-reactive memory devices.

  12. Standard Enthalpies of Formation of Solid Complexes of Lanthanide Nitrates with Alanine

    Institute of Scientific and Technical Information of China (English)

    杨旭武; 陈三平; 高胜利; 刘晓华; 史启祯

    2002-01-01

    The combustion energies of fourteen solid complexes of lanthanide nitrate with alanine were determined. The standard enthalpies of combustion, Δc,coor(s)H°, and standard enthalpies of formation, Δf,coor(s)H°, were calculated for these complexes. The relationship of Δc,coor(s)H° and Δf,coor(s)H° with the atomic numbers of the elements in the lanthanide series were examined. The results show that a certain amount of covalence is present in the chemical bond between the lanthanide cations and alanine.

  13. New arene ruthenium complexes with planar chirality

    OpenAIRE

    Therrien, Bruno; Süss-Fink, Georg

    2009-01-01

    1,2,4-Trimethyl-cyclohexadiene reacts with RuCl3 • nH2O in refluxing ethanol to afford quantitatively [RuCl2(1,2,4-C6H3Me3)]2 (1), the coordination of 1,2,4-trimethylbenzene to the ruthenium atom introducing planar chirality at the η6-arene ligand. The dinuclear complex 1 reacts with two equivalents of triphenylphosphine (PPh3) to give quantitatively, as a racemic mixture of enantiomers, [RuCl2(1,2,4-C6H3Me3)(PPh3)] (2), the structure of which has been determined by a single-crystal X-ray str...

  14. Studies on trivalent lanthanide complexes of bis-vanillin p-phenylenediamine

    International Nuclear Information System (INIS)

    The coordination interaction of lanthanide(III) chlorides with bis-vanillin o-phenylenediamine was studied by Ansari and Ahmad (1977). It was thought fruitful to compare these with the complexes of trivalent lanthanide ions with bis-vanillin p-phenylenediamine. The newly synthesized complexes were subjected to elemental, thermogravimetric and differential thermal analyses and their melting points, magnetic susceptibilities, molar conductances determined and infrared and electronic spectra taken. (author)

  15. Lanthanide complexes of an oxazoline-phenoxide hybrid chelate

    International Nuclear Information System (INIS)

    The synthesis of 2-(2'-hydroxy-3'-allylphenyl)-4,4-dimethyl-2-oxazoline, H-Allox (3), and lanthanide tris chelate complexes, mer-Ln(Allox)3 (Ln = La (4), Ce (5), Sm (6), Er (7), and Y (8)), derived from it are reported. A six-coordinate mer geometry without alkene coordination was confirmed in the solid state by X-ray crystallography for 5 and 7. Variable-temperature NMR experiments suggested that this is the most stable isomer in solution as well, although the inequivalent ligand environments undergo rapid averaging at room temperature for all five complexes. A mechanistic investigation indicated that this fluxional process is an intramolecular six-coordinate rearrangement, but it was not possible to distinguish between a Bailar (trigonal) or Ray-Dutt (rhombic) twist. Kinetic parameters for the fluxional process were determined by line shape analysis for 8 yielding ΔH = 24 ± 2 kJ mol-1 and ΔS = -99 ± 10 J mol-1 K-1. The structural and dynamic features of 4-8 were compared with the related In, Ga, and Al tris(2-oxazolylphenoxides). (author)

  16. Chromatographic separation of lanthanides into two groups based on kinetic differences in the decomposition of macrocycle/lanthanide complexes

    International Nuclear Information System (INIS)

    The separation of the lanthanides in two groups, based on differences in decomplexation rates of the LnDOTA entities (DOTA = 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid), is achieved on a sulphonate cation-exchange column (H+ form). The yttrium earths, from terbium to lutetium, are eluted first as Ln-DOTA-H species with 1.25 M HCl; the light lanthanides, from lanthanum to samarium inclusive, are eluted as uncomplexed ions at the end of the chromatogram, with more concentrated hydrochloric acid. Given an equimolar mixture of the Eu-DOTA and Gd-DOTA complexes as starting solution, 40% of the gadolinium can be recovered free from europium at the start of elution and 47% of the europium free from gadolinium at the end of the elution. (Auth.)

  17. VCD Studies on Chiral Characters of Metal Complex Oligomers

    OpenAIRE

    Hisako Sato; Akihiko Yamagishi

    2013-01-01

    The present article reviews the results on the application of vibrational circular dichroism (VCD) spectroscopy to the study of stereochemical properties of chiral metal complexes in solution. The chiral characters reflecting on the vibrational properties of metal complexes are revealed by measurements of a series of β-diketonato complexes with the help of theoretical calculation. Attention is paid to the effects of electronic properties of a central metal ion on vibrational energy l...

  18. Bimetallic lanthanide complexes that display a ratiometric response to oxygen concentrations

    OpenAIRE

    Sørensen, TJ; Kenwright, AM; Faulkner, S.

    2015-01-01

    A pair of hetero-bimetallic lanthanide complexes containing terbium and europium ions have been prepared by coupling kinetically stable complexes together using an Ugi methodology to incorporate a naphthyl chromophore. Both complexes exhibit emission from terbium and europium in solution. The terbium centred emission varies with dissolved oxygen concentration, while the europium intensity remains essentially constant in one of the complexes.

  19. Complexation of calyx[4]resorcinarene with bis(phenanthroline)lanthanide complexes in water-organic media

    International Nuclear Information System (INIS)

    The guest-host type complexing constants of calyx[4]resorcinarene (H8L) with [Ln(Phen)2]3+ cations (Phen - 1, 10-phenanthroline, Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) in neutral and low-alkaline water-organic (dimethylsulfoxide, isopropanol) media have been ascertained by the method of pH-metric titration. Essential increase in the complexes stability with their ordinal number increase from La3+ to Ho3+ in lanthanide series has been detected

  20. Calorimetric approach of lanthanides (3) complexation and extraction by malonamides; Approche calorimetrique de la complexation et de l'extraction des lanthanides (3) par les malonamides

    Energy Technology Data Exchange (ETDEWEB)

    Flandin, J.L

    2001-07-01

    In the field of long lived radionuclides separation, diamides are interesting extractants because of their ability to co-extract trivalent lanthanides and actinides, which is a preliminary and essential step in high level radioactive waste reprocessing. The research carried out contributes to a better understanding of the mechanisms and the aim is the determination of thermodynamics properties ({delta}{sub r}G, {delta}{sub r}H et {delta}{sub r}S) related to the complexation and the extraction of lanthanides(III) by malonamides. The first part of the document deals with the complexation of lanthanides(III) by an hydrosoluble diamide. The experimental results obtained by UV-visible spectrometry, TRLIF, NMR and microcalorimetric titration proved that lanthanides(III)-TEMA interactions in aqueous medium are very weak and that the complexation reaction is endothermic. The TEMA ligand still stays in the second coordination sphere of coordination of the lanthanide ion. The second part of this study focuses on the extraction of neodymium(III) nitrate by a lipophilic diamide which is an exothermic reaction. The influence of the composition of aqueous and organic phases on the thermodynamics properties {delta}{sub r}G et {delta}{sub r}H has been studied by microcalorimetric titration. The most influent parameter is the total concentration in extractant. As a consequence, thermodynamic values are very dependent on the organic phase organisation before and alter extraction. At the same time, this study showed the interest of the calorimetric approach for the analysis of basic reactions like diamide dilution and their organisation as oligomeric aggregates. (author)

  1. Molecular design of luminescent Eu(III) complexes as lanthanide lasing material and their optical properties

    International Nuclear Information System (INIS)

    Luminescent polymer (PMMA) containing a Eu(III) complex with a fast radiation rate and a high luminescence quantum efficiency (75 ± 5%) (bis-triphenylphosphineoxide)(tris-hexafluoroacetylacetonato)europium(III) (Eu(hfa)3(TPPO)2), was fabricated. The quantum yield and the radiation rate of the luminescent polymer were found to be 75 ± 5% and 1.1 x 103 s-1, respectively. An Eu(III) complex-doped polymer thin-film was also prepared by use of polyphenylsilsesquioxane (PPSQ) to construct a waveguide lanthanide laser. We propose a strategy for the molecular design of luminescent Eu(III) complexes aiming at lanthanide lasing

  2. Study of formation of complexes between tetracycline and lanthanide ions by optical and NMR spectroscopy

    International Nuclear Information System (INIS)

    The results of studies on the Eu3+ luminescence spectra in complexes with tetracycline, as well as the NMR spectra of the tetracycline complexes with La3+ and Yb3+ in water solutions are described. Participation of the tetracycline tricarbonylmethane groupings in interaction process with lanthanide ions is proved

  3. Conformation of lanthanides complexes of L-serine phosphate and ethanolamine phosphate in aqueous phase

    International Nuclear Information System (INIS)

    NMR paramagnetic shifts induced by rare earth cations lead to conformations of complexes in aqueous solution. A computer treatment is developped for complexes of L-serine phosphate and ethanolamine phosphate with lanthanides in acidic solution (pH=1 to 1.8). Angle and distance values are discussed with a hindered rotation about P-O1 bond

  4. Complexes of trivalent lanthanide ions with schiff base derived from vanillin and triethylenetetraamine

    International Nuclear Information System (INIS)

    Complexes of lanthanide(III) ions with the schiff base derived from vanillin and triethylenetetraamine have been synthesised and characterised on the basis of elemental analyses, molar conductance, magnetic moment, IR and thermal analysis data. The thermograms show the elimination (OH)(OCH3)C6H3CH-group at low temperatures before the elimination of triethylenetetraamine part corroborating the observation made on the basis of IR spectral data. This is a clear indication of the non-coordination of the phenolic hydroxyl groups. The lanthanide ions in the complexes exhibit eight coordination numbers. (author)

  5. Organometallic complex chemistry of plutonium and selected lanthanides

    International Nuclear Information System (INIS)

    This study deals with the metallo-organic chemistry of plutonium and also with that of some lanthanides. For plutonium, the conversion of Cs2PuCl6 with four equivalents KCp is investigated. In the series Sm, Gd, Dy and Er, compounds of the type Cp2LnX and the base adducts with acetonitrile are analysed. The ligand X passes the series Cl, N3, NCS and NCO. Both, the thermal and the vibrational spectroscopic behaviour is investigated. In addition, the effect of a changed ligand sphere on the optical spectrum is discussed. The adduct-free compounds are described by a ternary reaction not yet known from literature. For the first time, force constant calculations are carried out on metallo-organic compounds of lanthanides. With the exception of Cp2LnCl compounds, all compouds are presented for the first time in the framework of this study. (orig.)

  6. Synthesis and luminescent spectroscopy of lanthanide complexes with dimethylpyridine-2,6-dicarboxylate (dmpc)

    Energy Technology Data Exchange (ETDEWEB)

    Taha, Ziyad A., E-mail: tahaz33@just.edu.jo [Department of Applied Chemical Sciences, Faculty of Arts and Sciences, Jordan University of Science and Technology, Irbid 22110 (Jordan); Ajlouni, Abdulaziz M.; Hijazi, Ahmed K. [Department of Applied Chemical Sciences, Faculty of Arts and Sciences, Jordan University of Science and Technology, Irbid 22110 (Jordan); Al-Rawashdeh, Nathir A. [Department of Applied Chemical Sciences, Faculty of Arts and Sciences, Jordan University of Science and Technology, Irbid 22110 (Jordan); Department of Chemistry, United Arab Emirates University, Al Ain 15551 (United Arab Emirates); Al-Hassan, Khader A.; Al-Haj, Yaser A. [Department of Chemistry, Faculty of Science, Yarmouk University, 1163 Irbid (Jordan); Ebqa' ai, Mohammad A. [Al-Qunfudah Center For Scientific Research, Umm Al-Qura University, College in Al-Qunfudah, Makkah (Saudi Arabia); Altalafha, Ammar Y. [Department of Chemistry, Faculty of Science, Yarmouk University, 1163 Irbid (Jordan)

    2015-05-15

    A series of lanthanide complexes with the general formulae [Ln(dmpc)(NO{sub 3}){sub 2}(H{sub 2}O){sub 2}]NO{sub 3} (Ln=Pr, Nd, Sm, Eu, Gd, Tb, Dy, and Er) and [La(dmpc)(NO{sub 3}){sub 2}(H{sub 2}O){sub 2}]NO{sub 3} were prepared by direct reaction between hydrated lanthanide(III) nitrate and dimethylpyridine-2,6-dicarboxylate (dmpc) in a 1:1 M ratio in ethylacetate–chloroform mixture. The luminescence properties of the dmpc and its Ln(III) complexes were investigated in solid state and in methanol, DMF and DMSO solutions. The Tb–dmpc, Eu–dmpc, Sm–dmpc and Dy–dmpc complexes exhibit characteristic luminescence of Tb(III), Eu(III), Sm(III) and Dy(III) ions indicating energy transfer from the dmpc to the Ln(III) ions. Scavenging activities of the dmpc and its Ln(III) complexes on DPPH{sup •} free radical were investigated in DMSO solution at a different concentrations ranges. - Highlights: • Nine new lanthanide complexes with dmpc ligand are prepared and characterized. • Ln–dmpc {Ln=Eu, Tb, Sm, Dy} complexes exhibit characteristic emissions of Ln ions. • The solvent effect on the luminescence intensity is investigated. • The antioxidant activity of the dmpc is enhanced upon complexation with lanthanide.

  7. Luminescence studies of lanthanide complexation reactions: europium(III) with saccharin in water

    Energy Technology Data Exchange (ETDEWEB)

    Silber, Herbert B.; Maraschin, Victor; Paquette, Sarah; Smith, Steven

    2004-07-14

    Luminescence studies of lanthanide complexation have many advantages over those involving UV-Vis measurements. Because of the hypersensitive peaks and increased sensitivity to the environment surrounding europium, significantly lower metal ion concentrations are required for measurement, thereby allowing complexation studies to be more accurate and carried out at lower ionic strengths, which is closer to the biological ionic strength. In solid state X-ray studies between the lanthanides and saccharin, one or two saccharin molecules bind per lanthanide ion. Our studies in solution indicate that one saccharide ligand binds to europium(III), the same as in the solid. We are using emission and lifetime data to calculate the binding constants as a function of temperature in water.

  8. Extraction study of lanthanide nitrato complexes - the adogen-464NO3 - NH4NO3 system

    International Nuclear Information System (INIS)

    Extraction of lanthanides and yttrium was studied in the interval of ammonium nitrate concentrations from 1 to 10M, and of Adogen-464 nitrate concentrations from 0.00039 to 0.39M. From the aqueous phase separation factor and from the published stability constant for europium (Eu), stability constants for 1:1 complexes of lanthanum (La), neodymium (Nd), gadolinium (Gd), holmium (Ho), thulium (Tm), lutetium (Lu) and yttrium (Y) have been determined, at 1M ammonium nitrate concentration. Results show that stability constant decreases from 2.7 for La to 2.3 for Lu. In the range of Adogen-464 nitrate concentrations employed, lanthanides from La to Nd appear in the organic phase as 1:5 complexes, whereas lanthanides heavier than Nd appear also as 1:4 complexes. Relative values (with regard to lanthanum) of Gibbs energy, enthalpy (from the temperture effect) and entropy for formation of 1:5 complexes, and the position of yttrium within lanthanides have been determined. Conclusions are that the extracted 1:4 and 1:5 complexes are of the inner sphere type, with nitrate ions acting as bidentate ligands, and that the contribution from covalency to bonding is the same in the aquo ion and in the 1:5 nitrato complex. 5 figures, 1 table

  9. Actinides(3)/lanthanides(3) separation by nano-filtration assisted by complexation; Separation actinides(3)lanthanides(3) par nanofiltration assistee par complexation

    Energy Technology Data Exchange (ETDEWEB)

    Sorin, A

    2006-07-01

    In France, one of the research trend concerning the reprocessing of spent nuclear fuel consists to separate selectively the very radio-toxic elements with a long life to be recycled (Pu) or transmuted (Am, Cm, Np). The aim of this thesis concerns the last theme about actinides(III)/lanthanides(III) separation by a process of nano-filtration assisted by complexation. Thus, a pilot of tangential membrane filtration was designed and established in a glove box at the ATALANTE place of CEA-Marcoule. Physico-chemical characterisation of the Desal GH membrane (OSMONICS), selected to carry out actinides(III)/lanthanides(III) separation, was realized to determine the zeta potential of the active layer and its resistance to ionizing radiations. Moreover, a parametric study was also carried out to optimize the selectivity of complexation, and the operating conditions of complex retention (influences of the transmembrane pressure, solute concentration, tangential velocity and temperature). Finally, the separation of traces of Am(III) contained in a mixture of lanthanides(III), simulating the real load coming from a reprocessing cycle, was evaluated with several chelating agents such as poly-amino-carboxylic acids according to the solution acidity and the [Ligand]/[Cation(III)] ratio. (author)

  10. Experimental study and surface-complexation modelling of trivalent lanthanide ion sorption on haematite

    International Nuclear Information System (INIS)

    The sorption of two trivalent lanthanide ions (Ln3+), La3+ and Yb3+ on haematite is studied, using as a means of calculation the FITEQL code (Westall, 1982). The resulting values for the surface acidity constants are: pKas1int=6.38±0.04 and pKas2int=9.81±0.07. The lanthanide sorption is explained by way of the formation of the surface complexes SOHLn3+, SOLn2+, SOLn(OH)+ and SOLn(OH)2, where SOH denote an hydroxide surface group

  11. The electronic structure of the complexes of lanthanide ions with crown ethers

    International Nuclear Information System (INIS)

    The total energies of molecules, electronic structures, charge distribution and Mulliken's bond order in the complexes of lanthanide nitrates (or chlorides) with crown ethers have been calculated by using INDO method. The results have shown that the charge transfer L→Ln at coordination processes leads to the shift of the energy levels and weakening of the bond of Ln-O(NO/sub 3/) or Ln-Cl, and the molecular configuration with the lanthanide ions being coordinated to the ethereal oxygen atoms and the three bidentate nitrate ions (or chloride ions) on one side of the crown ring, is energetically the most preferable one

  12. Some remarks on the periodical change of the stability constants of the lanthanide complexes

    International Nuclear Information System (INIS)

    The correlations between the values of the lg K (K stability constant of the lanthanide complex) and the reciprocal of the ionic radius 1/r or the sum of the ionization potentials Σ31I for the lanthanide ions were reviewed for different ligands. A straight-line relationship (lg K'-lg K)/lg K' vs. (1/r'-1/r)/(1/r') or vs. (Σ31I'-Σ31I)/Σ31I' was found within the tetrads La-Nd, Gd-Ho and Er-Lu. (Author)

  13. A lanthanide complex for metal encapsulations and anion exchanges.

    Science.gov (United States)

    Sun, Yan-Qiong; Wan, Fang; Li, Xin-Xiong; Lin, Jian; Wu, Tao; Zheng, Shou-Tian; Bu, Xianhui

    2016-08-01

    A cationic lanthanide metalloligand with 3 dangling carboxylate groups on its periphery co-assembles with nitrate into a porous thermochromic solid responsive to both external cations and anions, owing to the presence of exchangeable NO3(-) as well as cation cavities arising from cooperative orientation of free carboxylate groups. An especially interesting feature is the structural memory effect during crystallization exhibited by the metalloligand, even after dissolution and binding to secondary cations (Cu(2+), Cd(2+)…). Moreover, the porous solid can undergo ion-exchange with various anions, leading to tunable thermochromic temperature and color range. PMID:27463609

  14. Self-assembly and photophysical properties of lanthanide dinuclear triple-helical complexes

    Energy Technology Data Exchange (ETDEWEB)

    Piguet, C.; Bernardinelli, G.; Williams, A.F. (Univ. of Geneva (Switzerland)); Buenzli, J.C.G. (Univ. of Lausanne (Switzerland)); Hopfgartner, G. (Hoffmann-La Roche, Basel (Switzerland))

    1993-09-08

    The dinucleating ligand bis[1-methyl-2-(6[prime]-[1[double prime]-(3,5-dimethoxybenzyl)benzimidazol-2[double prime]-yl]pyrid-2[prime]-yl)benzimidazol-5-yl]methane (L) reacts with lanthanide perchlorates to give dinuclear 2:3 complexes [Ln[sub 2](L)[sub 3

  15. The first uranyl-lanthanide hetero metallic complexes: metal-organic frameworks with DOTA and oxalato ligands

    International Nuclear Information System (INIS)

    Reaction of uranyl and lanthanide nitrates with DOTA (H4L) under hydrothermal conditions gave the first uranyl-lanthanide hetero metallic complexes, [(UO2)2Ln(L)(C2O4)(OH)(H2O)]· 3H2O [Ln = Gd (1) or Eu (2)]. (author)

  16. Synthesis, characterization and luminescent properties of lanthanide complexes with an unsymmetrical tripodal ligand

    International Nuclear Information System (INIS)

    Solid complexes of lanthanide nitrates with a new unsymmetrical tripodal ligand, bis[(2'-benzylaminoformyl)phenoxyl)ethyl](ethyl)amine (L) have been synthesized and characterized by elemental analysis, infrared spectra and molar conductivity measurements. At the same time, the luminescent properties of the Sm(III), Eu(III), Tb(III) and Dy(III) nitrate complexes in solid state were also investigated. Under the excitation of UV light, these complexes exhibited characteristic emission of central metal ions

  17. Evidence of different stoichiometries for the limiting carbonate complexes of lanthanides(3)

    International Nuclear Information System (INIS)

    Two stoichiometries have been proposed by different laboratories to interpret measurements on the limiting carbonate complexes of An3+ and Ln3+ cations. The study of the solubility of double carbonates (AlkLn(CO3)2,xH2O) in concentrated carbonate solutions at room temperature and high ionic strengths has shown that on the one hand the lightest lanthanides (La and Nd) form Ln(CO3)45- whereas the heaviest (Eu and Dy) form Ln(CO3)33- in the studied chemical conditions, and on the other hand, that the kinetics of precipitation of double carbonates depends on the alkali metal and the lanthanide ions. The existence of two stoichiometries for the limiting carbonate complexes was confirmed by capillary electrophoresis hyphenated to an inductively coupled plasma mass spectrometer (CE-ICP-MS), used to extend the study to the whole series of lanthanides (except Ce, Pm and Yb). Two behaviours have been put forward comparing the electrophoretic mobilities: La to Tb form Ln(CO3)45- while Dy to Lu form Ln(CO3)33-. Measurements by time resolved laser fluorescence spectroscopy (TRLFS) on Eu(III) indicate small variations of the geometry of Eu(CO3)33- complex, specially with Cs+. Although analogies are currently used among the 4f-block trivalent elements, different aqueous speciations are evidenced in concentrated carbonate solutions across the lanthanide series. (author)

  18. Structural, Magnetic and Luminescent Properties of Lanthanide Complexes with N-Salicylideneglycine

    Science.gov (United States)

    Vančo, Ján; Trávníček, Zdeněk; Kozák, Ondřej; Boča, Roman

    2015-01-01

    A series of anionic heavy lanthanide complexes, involving the N-salicylideneglycinato(2-) Schiff base ligand (salgly) and having the general formula K[Ln(salgly)2(H2O)2]∙H2O (1–6), where Ln stands for Gd, Tb, Dy, Ho, Er and Tm, was prepared using the one-pot template synthesis. The complexes were thoroughly characterized by elemental and Thermogravimetric/Differential Thermal Analyses (TG/DTA), Fourier Transform Infrared Spectroscopy (FT-IR), and photoluminescence spectroscopies, electrospray-ionization mass spectrometry, and their magnetic properties were studied by temperature-dependent dc magnetic measurements using the superconducting quantum interference device (SQUID). The X-ray structure of the terbium(III) complex (2), representing the unique structure between the lanthanide complexes of N-salicylideneamino acids, was determined. The results of spectral and structural studies revealed the isostructural nature of the prepared complexes, in which the lanthanide ion is octacoordinated by two O,N,O-donor salgly ligands and two aqua ligands. The analysis of magnetic data confirmed that the complexes behave as paramagnets obeying the Curie law. The results of photoluminescence spectral studies of the complexes showed the different origin in their luminescent properties between the solid state and solution. An antenna effect of the Schiff base ligand was observed in a powder form of the complex only, while it acts as a fluorophore in a solution. PMID:25927576

  19. Structural, magnetic and luminescent properties of lanthanide complexes with N-salicylideneglycine.

    Science.gov (United States)

    Vančo, Ján; Trávníček, Zdeněk; Kozák, Ondřej; Boča, Roman

    2015-01-01

    A series of anionic heavy lanthanide complexes, involving the N-salicylideneglycinato(2-) Schiff base ligand (salgly) and having the general formula K[Ln(salgly)₂(H₂O)₂]∙H₂O (1-6), where Ln stands for Gd, Tb, Dy, Ho, Er and Tm, was prepared using the one-pot template synthesis. The complexes were thoroughly characterized by elemental and Thermogravimetric/Differential Thermal Analyses (TG/DTA), Fourier Transform Infrared Spectroscopy (FT-IR), and photoluminescence spectroscopies, electrospray-ionization mass spectrometry, and their magnetic properties were studied by temperature-dependent dc magnetic measurements using the superconducting quantum interference device (SQUID). The X-ray structure of the terbium(III) complex (2), representing the unique structure between the lanthanide complexes of N-salicylideneamino acids, was determined. The results of spectral and structural studies revealed the isostructural nature of the prepared complexes, in which the lanthanide ion is octacoordinated by two O,N,O-donor salgly ligands and two aqua ligands. The analysis of magnetic data confirmed that the complexes behave as paramagnets obeying the Curie law. The results of photoluminescence spectral studies of the complexes showed the different origin in their luminescent properties between the solid state and solution. An antenna effect of the Schiff base ligand was observed in a powder form of the complex only, while it acts as a fluorophore in a solution. PMID:25927576

  20. Structural, Magnetic and Luminescent Properties of Lanthanide Complexes with N-Salicylideneglycine

    Directory of Open Access Journals (Sweden)

    Ján Vančo

    2015-04-01

    Full Text Available A series of anionic heavy lanthanide complexes, involving the N-salicylideneglycinato(2- Schiff base ligand (salgly and having the general formula K[Ln(salgly2(H2O2]∙H2O (1–6, where Ln stands for Gd, Tb, Dy, Ho, Er and Tm, was prepared using the one-pot template synthesis. The complexes were thoroughly characterized by elemental and Thermogravimetric/Differential Thermal Analyses (TG/DTA, Fourier Transform Infrared Spectroscopy (FT-IR, and photoluminescence spectroscopies, electrospray-ionization mass spectrometry, and their magnetic properties were studied by temperature-dependent dc magnetic measurements using the superconducting quantum interference device (SQUID. The X-ray structure of the terbium(III complex (2, representing the unique structure between the lanthanide complexes of N-salicylideneamino acids, was determined. The results of spectral and structural studies revealed the isostructural nature of the prepared complexes, in which the lanthanide ion is octacoordinated by two O,N,O-donor salgly ligands and two aqua ligands. The analysis of magnetic data confirmed that the complexes behave as paramagnets obeying the Curie law. The results of photoluminescence spectral studies of the complexes showed the different origin in their luminescent properties between the solid state and solution. An antenna effect of the Schiff base ligand was observed in a powder form of the complex only, while it acts as a fluorophore in a solution.

  1. Theoretical study of the structure and reactivity of lanthanide and actinide based organometallic complexes

    International Nuclear Information System (INIS)

    In this PhD thesis, lanthanide and actinide based organometallic complexes are studied using quantum chemistry methods. In a first part, the catalytic properties of organo-lanthanide compounds are evaluated by studying two types of reactions: the catalytic hydro-functionalization of olefins and the polymerisation of polar monomers. The reaction mechanisms are theoretically determined and validated, and the influence of possible secondary non productive reactions is envisaged. A second part focuses on uranium-based complexes. Firstly, the electronic structure of uranium metallocenes is analysed. An analogy with the uranyl compounds is proposed. In a second chapter, two isoelectronic complexes of uranium IV are studied. After validating the use of DFT methods for describing the electronic structure and the reactivity of these compounds, it is shown that their reactivity difference can be related to a different nature of chemical bonding in these complexes. (author)

  2. Manganese- and Lanthanide-Based 1D Chiral Coordination Polymers as an Enantioselective Catalyst for Sulfoxidation.

    Science.gov (United States)

    Yadav, Munendra; Bhunia, Asamanjoy; Jana, Salil K; Roesky, Peter W

    2016-03-21

    The chiral 1D-coordination polymers (CP) {[Ln2(MnLCl)2(NO3)2(dmf)6(H2O)2]·xH2O}n [Ln = Pr (1), Nd (2), Sm (3), and Gd (4)] were synthesized by the reaction of N,N'-bis(4-carboxysalicylidene)cyclohexanediamine (H4L) with [MnCl2·4(H2O)] and [Ln(NO3)3·x(H2O)] in the presence of dmf/pyridine at 90 °C. The polymers consist of manganese-salen-based moieties having carboxylate linkers connected to rare earth atoms in a 1D-chain structure. The polymers are very easily accessible. A one-step synthesis for the ligand and a second step for the preparation of the 1D coordination polymers starting from commercially available material are needed. The solid state structures of 1-4 were established by single-crystal X-ray diffraction. Compounds 1-4 were investigated as heterogeneous catalysts for the sulfoxidation reaction of various alkyl and aryl sulfides. The influence of various solvents and oxidizing agents on the catalytic reaction was examined. It was found that the catalysts were active for more than one reaction cycle without significant loss of activity. For phenylsulfide with 1 mol % of the catalyst 4, a maximum conversion 100% and a chemoselectivity 88% were observed. PMID:26923559

  3. Synthesis and Characterization of DOTA-(amide)4 Derivatives: Equilibrium and Kinetic Behavior of Their Lanthanide(III) Complexes

    OpenAIRE

    Pasha, Azhar; Tircsó, Gyula; Benyó, Enikő Tircsóné; Brücher, Ernő; Sherry, A. Dean

    2007-01-01

    Lanthanide complexes of tetraamide derivatives of DOTA are of interest today because of their application as chemical exchange saturation transfer (CEST) agents for magnetic resonance imaging (MRI). The protonation constants of some simple tetraamide derivatives of DOTA and the stability constants of the complexes formed with some endogenous metal ions, namely Mg2+, Ca2+, Cu2+, Zn2+, and lanthanide(III) ions, have been studied. These complexes were found to be considerably less stable than th...

  4. Chiral diamine-silver(I)-alkene complexes: a quantum chemical and NMR study

    DEFF Research Database (Denmark)

    Kieken, Elsa; Wiest, Olaf; Helquist, Paul; Cucciolito, Maria E.; Flores, Germana; Vitagliano, Aldo; Norrby, Per-Ola

    2005-01-01

    The ability of chiral diamine silver complexes to bind chiral and prochiral alkenes has been analyzed in detail. The stereoselectivity in binding of alkenes to a chiral ethanediamine silver complex has been investigated by NMR. The low-energy conformations of several small model complexes have be...

  5. Lanthanide--humic substances complexation. II. Calibration of humic ion-binding model V.

    Science.gov (United States)

    Sonke, Jeroen E

    2006-12-15

    The experimental complexation of the lanthanides (Sc, Y, and rare earth elements) with Suwannee river fulvic acid, Leonardite coal humic acid, and Elliot soil humic acid is described with Humic Ion-Binding Model V. The fitted intrinsic equilibrium constants for metal-proton exchange, pKMHA, for Eu3+ are similar to previously published experimental fits, and linear free energy relationship (LFER) estimated values. The experimentally observed lanthanide contraction effect in REE-humic complex stability is reflected in the gradual decrease in pKMHA from La to Lu. In Model V, a decrease in pKMHA from La to Lu indicates an increase in complex stability. Fitted pKMHA values for heavy REE are lower than those estimated by LFERs. Consequently, REE fractionation by humic substances complexation could be more pronounced than previously thought. Recommended pKMHA values for lanthanide-fulvic and -humic acid complexation are derived by superimposing the fitted trends in pKMHA for all REE, i.e., the decrease in pKMHA from La to Lu, on the average Eu pKMHA value for all literature datasets. These results will allow modeling assessments of organic matter induced REE fractionation in aquatic environments, taking into account changes in pH, ionic strength, and ion competition. A simulation of dissolved REE speciation in an average world river suggests that organic matter outcompetes carbonate complexation, even under alkaline conditions. PMID:17256484

  6. Synthesis, characterization and luminescent properties of lanthanide complexes with a novel multipodal ligand

    Science.gov (United States)

    Yan, Zhen-Zhong; Hou, Na; Wang, Cong-Min

    2015-02-01

    Solid complexes of lanthanide nitrates with an novel multipodal ligand, 1,2,4,5-tetramethyl-3,6-bis{N,N-bis[((2‧-furfurylaminoformyl)phenoxyl)ethyl]-aminomethyl}-benzene (L) have been synthesized and characterized by elemental analysis, infrared spectra and molar conductivity measurements. At the same time, the luminescent properties of the Sm(III), Eu(III), Tb(III) and Dy(III) nitrate complexes in solid state were investigated. Under the excitation of UV light, these complexes exhibited characteristic emission of central metal ions. The lowest triplet state energy level of the ligand indicates that the triplet state energy level (T1) of the ligand matches better the resonance level of Tb(III) than other lanthanide ions.

  7. Luminescence, non-radiative processes, and quantum yields in lanthanide complexes

    International Nuclear Information System (INIS)

    Full text: The investigation and design of lanthanide complexes as efficient light-conversion devices (LCD) has become an important research theme, being pursued by several groups, for fundamental and applied reasons. Efficient LCD's may find many applications, such as luminescent probes in biomedical assays or thin film electroluminescent devices. In order to optimize the quantum yield and light output of a LCD, several processes must be controlled: (i) the ligand absorption and internal decay processes; (ii) the efficiency of the ligand to metal energy transfer; and (iii) the luminescence efficiency of the metal ion. Also, other aspects such as photostability, volatility and solubility may be critical to many applications and must be considered. In this presentation we will first give an overview of the work which has been done to date on the development and applications of LCD's based on lanthanide complexes. We will then focus on the work of our group, which aims at gaining insight into the factors determining the quantum yields of lanthanide complexes, thus ultimately allowing the design of efficient LCD's. To achieve such a goal we have adopted a strategy based upon both theoretical and experimental approaches. Therefore, we have investigated the solid state photophysical properties (viz. luminescence, quantum yields, and excited state decay times) of a number of new lanthanide complexes, with general formulae Ln(L)3 B (where Ln is Eu3+, Gd3+, or Tb3+; L is a ligand such as a b-diketone, an aminopirazine carboxilic acid derivative, a cyclic ketone, etc.; and B is a second ligand such as 1,10-phenanthroline, bipyridine, etc., and its N-oxide analogs). Moreover, our group has been successfully developing theoretical models to determine the efficiency of the ligand-to-lanthanide ion energy transfer and the luminescence quantum yields of lanthanide complexes. The results show that the quantum yields can be enhanced by an appropriate choice of ligands and are

  8. Lanthanides and trivalent actinides complexation by tripyridyl triazine, applications to liquid-liquid extraction

    International Nuclear Information System (INIS)

    The protonation constants of TPTZ (tripyridyl (2) - 2,4,6 triazine 1,3,5) have been measured: pKa1 = 3.8 and pKa2 = 2.7. (I = 1M, KCl). TPTZ can be autoassociated as (HTPTZ)sub(x)sup(x+) (x=3 or 4). The Am TPTZ3+ formation constant (log β = 4.22) is more stable than the lanthanides ones: log β1 = 2.23/3.16/2.81/3.35/3.11/3.00/2.50/2.43/2.43/2.03./2.00/2.09 and 2.3 respectively for La/Pr/Nd/Sm/Eu/Gd/Tb/Dy/Ho/Er/Tm/Yb and Lu. The selectivity of TPTZ is applied to investigate the groups separation actinides (III)-lanthanides by a liquid-liquid extraction procedure, from nitric acid into several diluents. Acidic extractants dibutylthiophosphoric, di-2 ethylhexyldithiophosphoric, α-bromocapric (H α B Cr10) or dinonylnaphtalensulfonic (HDNNS) acid were used to insure the organic complexes electroneutrality. Am(III) and Cm(III) and lanthanides are extracted into decanol as M(α Br C10)3 and MTPZ (α Br C10)3 this last complex is more stable with actinides (III) than with lanthanides (log Kew = -3,1 and -3,9 respectively). HDNNS-TPTZ mixtures form inverted micelles in t-butylbenzene and can extract the actinides 20 times better than the lanthanides from 0.3 M HNO3. We explained qualitatively and quantitatively the extraction data, by assuming that HDNNS-TPTZ micelles behave like a 3rd phase

  9. Luminescence intensification of lanthanide complexes by silver nanoparticles incorporated in sol-gel matrix

    Institute of Scientific and Technical Information of China (English)

    Renata Reisfeld; Marek Pietraszkiewicz; Tsiala Saraidarov; Viktoria Levchenko

    2009-01-01

    We present how the luminescence of europium RR-2-P-oxides complexes can be increased by interaction of electronic levels of the complex with the radiation field of silver nanopatticles (NPs).The procedure by which silver NPs are formed in a sol-gel polyurethane matrix precursor was elaborated.The formed Ag NPs were combined with Eu complex incorporated in ormocer matrix.The emission spectra of the complexes without silver NPs were compared with spectra of the same complexes with addition of silver NPs.As the result of the interaction of the electronic levels of lanthanide ligands with silver plasmons,dramatic increase of luminescence was observed.

  10. Five chiral Cd(II) complexes with dual chiral components: Effect of positional isomerism, luminescence and SHG response

    International Nuclear Information System (INIS)

    Five chiral Cd(II) complexes with dual chiral components have been synthesized by using a series of (1R,2R)–N1,N2-bis(pyridinylmethyl)cyclohexane-1,2-diamine ligands with different N-positions of pyridyl rings and Cd(NO3)2. The circular dichroism (CD) spectra and second-harmonic generation (SHG) efficiency measurements confirmed that they are of structural chirality in the bulk samples. The luminescent properties indicated that they may have potential applications as optical materials. The formation of discrete mononuclear and binuclear complexes, and one-dimensional chains may be attributed to positional isomerism of the ligands. - Graphical abstract: Five chiral Cd(II) complexes with dual chiral components have been synthesized by using a series of chiral ligands with different N-positions of pyridyl rings. - Highlights: • Five chiral Cd(II) complexes with dual chiral components have been synthesized. • CD spectra and SHG efficiency of the bulk samples have been measured. • The complexes display luminescent properties

  11. Five chiral Cd(II) complexes with dual chiral components: Effect of positional isomerism, luminescence and SHG response

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Lin, E-mail: lcheng@seu.edu.cn [Pharmaceutical Research Center, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, Southeast University, Nanjing 211189 (China); Wang, Jun; Yu, Hai-Yan; Zhang, Xiu-Ying [Pharmaceutical Research Center, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Gou, Shao-Hua, E-mail: sgou@seu.edu.cn [Pharmaceutical Research Center, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, Southeast University, Nanjing 211189 (China); Fang, Lei [Pharmaceutical Research Center, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, Southeast University, Nanjing 211189 (China)

    2015-01-15

    Five chiral Cd(II) complexes with dual chiral components have been synthesized by using a series of (1R,2R)–N{sup 1},N{sup 2}-bis(pyridinylmethyl)cyclohexane-1,2-diamine ligands with different N-positions of pyridyl rings and Cd(NO{sub 3}){sub 2}. The circular dichroism (CD) spectra and second-harmonic generation (SHG) efficiency measurements confirmed that they are of structural chirality in the bulk samples. The luminescent properties indicated that they may have potential applications as optical materials. The formation of discrete mononuclear and binuclear complexes, and one-dimensional chains may be attributed to positional isomerism of the ligands. - Graphical abstract: Five chiral Cd(II) complexes with dual chiral components have been synthesized by using a series of chiral ligands with different N-positions of pyridyl rings. - Highlights: • Five chiral Cd(II) complexes with dual chiral components have been synthesized. • CD spectra and SHG efficiency of the bulk samples have been measured. • The complexes display luminescent properties.

  12. Physical characteristics of lanthanide complexes that act as magnetization transfer (MT) contrast agents

    Science.gov (United States)

    Zhang, Shanrong; Sherry, A. Dean

    2003-02-01

    Rapid water exchange is normally considered a prerequisite for efficient Gd 3+-based MRI contrast agents. Yet recent measures of exchange rates in some Gd 3+ complexes have shown that water exchange can become limiting when such complexes are attached to larger macromolecular structures. A new class of lanthanide complexes that display unusually slow water exchange (bound water lifetimes ( τM298) > 10 μs) has recently been reported. This apparent disadvantage may be taken advantage of by switching the metal ion from gadolinium(III) to a lanthanide that shifts the bound water resonance substantially away from bulk water. Given appropriate water exchange kinetics, one can then alter the intensity of the bulk water signal by selective presaturation of this highly shifted, Ln3+-bound water resonance. This provides the basis of a new method to alter MR image contrast in tissue. We have synthesized a variety of DOTA-tetra(amide) ligands to evaluate as potential magnetization transfer (MT) contrast agents and found that the bound water lifetimes in these complexes are sensitive to both ligand structure (a series of Eu 3+ complexes have τM298 values that range from 1 to 1300 μs) and the identity of the paramagnetic Ln3+ cation (from 3 to 800 μs for a single ligand). This demonstrates that it may be possible either to fine-tune the ligand structure or to select proper lanthanide cation to create an optimal MT agent for any clinical imaging field.

  13. Reversible recruitment and emission of DO3A-derived lanthanide complexes at ligating molecular films on gold.

    Science.gov (United States)

    Lehr, Joshua; Bennett, Jamie; Tropiano, Manuel; Sørensen, Thomas J; Faulkner, Stephen; Beer, Paul D; Davis, Jason J

    2013-02-01

    The recruitment of DO3A-derived lanthanide complexes by ligation to isophthalic acid and catechol-modified gold surfaces, and their resulting sensitization, is reported herein. Predictably pH-dependent surface recruitment is associated with the expected fingerprint europium and terbium emission characteristics. The intensity of the lanthanide luminescence scales exponentially with spacer length, indicating a strong quenching interaction between the lanthanide and the gold surface. The switchable catechol oxidation state provides a means of electrochemically triggering the release of prior ligated complexes. PMID:23320931

  14. Correlation of retention of lanthanide and actinide complexes with stability constants and their speciation

    Energy Technology Data Exchange (ETDEWEB)

    Datta, A.; Sivaraman, N.; Viswanathan, K.S.; Ghosh, Suddhasattwa; Srinivasan, T.G.; Vasudeva Rao, P.R. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Chemistry Group

    2013-03-01

    The present study describes a correlation that is developed from retention of lanthanide and actinide complexes with the stability constant. In these studies, an ion-pairing reagent, camphor-10-sulphonic acid (CSA) was used as the modifier and organic acids such as {alpha}-hydroxy isobutyric acid ({alpha}-HIBA), mandelic acid, lactic acid and tartaric acid were used as complexing reagent for elution. From these studies, a correlation has been established between capacity factor of a metal ion, concentration of ion-pairing reagent and complexing agent with the stability constant of metal complex. Based on these studies, it has been shown that the stability constant of lanthanide and actinide complexes can be estimated using a single lanthanide calibrant. Validation of the method was carried out with the complexing agents such as {alpha}-HIBA and lactic acid. It was also demonstrated that data from a single chromatogram can be used for estimation of stability constant at various ionic strengths. These studies also demonstrated that the method can be applied for estimation of stability constant of actinides with a ligand whose value is not reported yet, e.g., ligands of importance in the lanthanide-actinide separations, chelation therapy etc. The chromatographic separation method is fast and the estimation of stability constant can be done in a very short time, which is a significant advantage especially in dealing with radioactive elements. The stability constant data was used to derive speciation data of plutonium in different oxidation states as well as that of americium with {alpha}-HIBA. The elution behavior of actinides such as Pu and Am from reversed phase chromatographic technique could be explained based on these studies. (orig.)

  15. Polymetallic lanthanide (III) complexes for the design of new luminescent materials

    International Nuclear Information System (INIS)

    The incorporation of f elements in highly organized polymetallic complexes is of great interest in supramolecular chemistry and allows the combination of their nano-scopic size with the magnetic or optical properties of the metal ions. However due to the difficulty in controlling the coordination environment of these ions, the assembly of lanthanide-based polynuclear architectures has lagged behind that of other systems. These factors make the rational design for the construction of supramolecular lanthanide complexes quite challenging. In order to better understand the factors determining the assembly of lanthanide-based polymetallic arrays, we designed two different types of organic ligands, which favor, in one case, formation of infinite polymetallic complexes (coordination polymers), and in the case the assembly of discrete polymetallic architectures. Thus, we show that the use of flexible and multi-dentate picolinate-derivative ligands enables the formation of infinite and luminescent infinite frameworks which display very interesting luminescent properties. Geometry of the ligand has a great influence on the final network architecture. Particularly, implementation of four picolinate units within a tetrapodal ligand results in the controlled assembly of 1-D coordination polymers. Conversely to favor the controlled assembly of discrete polymetallic arrays we use dissymmetric ligands which displays low denticity. Complexation studies of a tridentate 8- hydroxyquinoline-derivative ligand as well as a tetradentate ligand possessing an oxazoline ring are presented. (author)

  16. Quantum chemical prediction of paramagnetic NMR spectra of lanthanide complexes with salicylic acid in water solution

    International Nuclear Information System (INIS)

    17O and 13C paramagnetic NMR (PNMR) shifts have been calculated for Gd complexes with salicylic acid in water solution. These complexes served us as model compounds for simulation of more complicated lanthanide complexes with humic acids. The obtained data demonstrate that paramagnetic NMR spectra are very sensitive to the bonding details of the ligand. Our calculations suggest that formation of Gd(III) complex with salicylic acid in water solution via carboxyl group with uni-dentate coordination is preferable. New experimental studies with the enriched 17O and 13C nuclei of carboxylate groups of the salicylic and humic acids are extremely desirable

  17. THE BIMODAL MOLECULAR WEIGHT DISTRIBUTION OF cis-POLYBUTADIENE POLYMERIZED WITH LANTHANIDE COMPLEX CATALYSTS

    Institute of Scientific and Technical Information of China (English)

    CHENG Rongshi; HU Huizhen; JIANG Liansheng

    1987-01-01

    The variation of the molecular weight and molecular weight distribution of cis-polybutadiene in the course of polymerization catalyzed by lanthanide complex composed of triisobutyl aluminium or diisobutyl aluminium hydride was investigated by osmometry, viscometry and size exclusion chromatography. By analyzing the experimental data, the reasons of the appearance of bimodal molecular weight distribution were elucidated and the possible mechanisms of polymerization were discussed.

  18. Actinides(3)/lanthanides(3) separation by nano-filtration assisted by complexation

    International Nuclear Information System (INIS)

    In France, one of the research trend concerning the reprocessing of spent nuclear fuel consists to separate selectively the very radio-toxic elements with a long life to be recycled (Pu) or transmuted (Am, Cm, Np). The aim of this thesis concerns the last theme about actinides(III)/lanthanides(III) separation by a process of nano-filtration assisted by complexation. Thus, a pilot of tangential membrane filtration was designed and established in a glove box at the ATALANTE place of CEA-Marcoule. Physico-chemical characterisation of the Desal GH membrane (OSMONICS), selected to carry out actinides(III)/lanthanides(III) separation, was realized to determine the zeta potential of the active layer and its resistance to ionizing radiations. Moreover, a parametric study was also carried out to optimize the selectivity of complexation, and the operating conditions of complex retention (influences of the transmembrane pressure, solute concentration, tangential velocity and temperature). Finally, the separation of traces of Am(III) contained in a mixture of lanthanides(III), simulating the real load coming from a reprocessing cycle, was evaluated with several chelating agents such as poly-amino-carboxylic acids according to the solution acidity and the [Ligand]/[Cation(III)] ratio. (author)

  19. Novel lanthanide complexes constructed from 3, 4-dimethoxybenzoic acid: crystal structures, spectrum and thermochemical properties

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Xiao-Xia; Wu, Jun-Chen [Testing and Analysis Center, Hebei Normal University, Shijiazhuang 050024 (China); College of Chemistry & Material Science, Hebei Normal University, Shijiazhuang 050024 (China); Ren, Ning, E-mail: ningren9@163.com [College of Chemical engineering & Material, Handan College, Handan 056005 (China); Zhao, Chun-Li [Raoyang High School of Hebei, Raoyang 053900 (China); Zhang, Jian-Jun, E-mail: jjzhang6@126.com [Testing and Analysis Center, Hebei Normal University, Shijiazhuang 050024 (China); College of Chemistry & Material Science, Hebei Normal University, Shijiazhuang 050024 (China); Zong, Guang-Cai; Gao, Jie [Testing and Analysis Center, Hebei Normal University, Shijiazhuang 050024 (China); College of Chemistry & Material Science, Hebei Normal University, Shijiazhuang 050024 (China)

    2015-09-10

    Graphical abstract: Four novel lanthanide coordination polymers [Ln(3,4-DMOBA){sub 3}(H{sub 2}O){sub 2}]·H{sub 2}O·C{sub 2}H{sub 5}OH (Ln = Sm(1), Tb(2), Dy(3), Ho(4); 3,4-DMOBA = 3, 4-dimethoxybenzoate) have been hydrothermal synthesized and characterized. Single crystal structures indicates 1 D stucture of the title complexes are linked by hydrogen bonds to form a three-dimensional (3-D) structure. Complex 2 exhibits the characteristic emission of Tb{sup 3+} ion({sup 5}D{sub 4} → {sup 7}F{sub 6-3}). The investigation of TG-FTIR and IR spectra of the evolved gases shows uncoordinated water and ethanol molecules tend to lose firstly, and then 3,4-DMOBA ligands begin to decompose. - Highlights: • Four lanthanide coordination polymers were synthesized and characterized. • 1-D chain structures of the title complexes are are linked by hydrogen bonds to form a 3-D structures. • Thermal decomposition processes of the title complexes were studied using TG-FTIR techniques. • IR spectra of evolved gases in thermal decomposition process were obtained and analyzed. - Abstract: Four novel lanthanide complexes [Ln(3,4-DMOBA){sub 3}(H{sub 2}O){sub 2}]·H{sub 2}O·C{sub 2}H{sub 5}OH (Ln = Sm(1), Tb(2), Dy(3), Ho(4); 3,4-DMOBA = 3, 4-dimethoxybenzoate) have been hydrothermal synthesized and characterized. Structural analyses reveal that adjacent lanthanide ions are connected by 3,4-DMOBA ligands adopting bridging bidentate mode to generate one-dimensional (1-D) structure with the uncoordinated water and ethanol molecules. 1-D structures are linked by hydrogen bonds to form a three-dimensional (3-D) structure, which is rarely observed in lanthanide carboxylic acids complexes. Under the radiation of UV light, complex 2 exhibits the characteristic emission of Tb{sup 3+} ion ({sup 5}D{sub 4} → {sup 7}F{sub 6-3}). The thermal decomposition mechanism is investigated by TG-FTIR technology. IR spectra of the evolved gases show that the uncoordinated water and ethanol

  20. Novel lanthanide complexes constructed from 3, 4-dimethoxybenzoic acid: crystal structures, spectrum and thermochemical properties

    International Nuclear Information System (INIS)

    Graphical abstract: Four novel lanthanide coordination polymers [Ln(3,4-DMOBA)3(H2O)2]·H2O·C2H5OH (Ln = Sm(1), Tb(2), Dy(3), Ho(4); 3,4-DMOBA = 3, 4-dimethoxybenzoate) have been hydrothermal synthesized and characterized. Single crystal structures indicates 1 D stucture of the title complexes are linked by hydrogen bonds to form a three-dimensional (3-D) structure. Complex 2 exhibits the characteristic emission of Tb3+ ion(5D4 → 7F6-3). The investigation of TG-FTIR and IR spectra of the evolved gases shows uncoordinated water and ethanol molecules tend to lose firstly, and then 3,4-DMOBA ligands begin to decompose. - Highlights: • Four lanthanide coordination polymers were synthesized and characterized. • 1-D chain structures of the title complexes are are linked by hydrogen bonds to form a 3-D structures. • Thermal decomposition processes of the title complexes were studied using TG-FTIR techniques. • IR spectra of evolved gases in thermal decomposition process were obtained and analyzed. - Abstract: Four novel lanthanide complexes [Ln(3,4-DMOBA)3(H2O)2]·H2O·C2H5OH (Ln = Sm(1), Tb(2), Dy(3), Ho(4); 3,4-DMOBA = 3, 4-dimethoxybenzoate) have been hydrothermal synthesized and characterized. Structural analyses reveal that adjacent lanthanide ions are connected by 3,4-DMOBA ligands adopting bridging bidentate mode to generate one-dimensional (1-D) structure with the uncoordinated water and ethanol molecules. 1-D structures are linked by hydrogen bonds to form a three-dimensional (3-D) structure, which is rarely observed in lanthanide carboxylic acids complexes. Under the radiation of UV light, complex 2 exhibits the characteristic emission of Tb3+ ion (5D4 → 7F6-3). The thermal decomposition mechanism is investigated by TG-FTIR technology. IR spectra of the evolved gases show that the uncoordinated water and ethanol molecules lose in the first step. And then 3,4-DMOBA ligand is decomposed into H2O, CO2 and other gaseous molecules as well as the gaseous

  1. Chiral de Rham complex on Riemannian manifolds and special holonomy

    OpenAIRE

    Ekstrand, Joel; Heluani, Reimundo; Kallen, Johan; Zabzine, Maxim

    2010-01-01

    Interpreting the chiral de Rham complex (CDR) as a formal Hamiltonian quantization of the supersymmetric non-linear sigma model, we suggest a setup for the study of CDR on manifolds with special holonomy. We show how to systematically construct global sections of CDR from differential forms, and investigate the algebra of the sections corresponding to the covariantly constant forms associated with the special holonomy. As a concrete example, we construct two commuting copies of the Odake alge...

  2. Lanthanide perchlorate complexes of quinoline-1-oxide and isoquinoline-2-oxide

    OpenAIRE

    Kalyanasundaram, R; Navaneetham, NS; Soundararajan, S.

    1985-01-01

    Complexes of lanthanide perchlorates with quinoline-1-oxide and isoquinoline-2-oxide have been isolated for the first time characterised by analysis, conductance and IR, NMR and electronic spectoral studies. The complexes of quinoline-1-oxide have the composition $Ln(QNO)_8$$(ClO_4)_3$ where Ln = La, Pr or Nd and $Ln(QNO)_7$ where Ln = Gd, Dy, Ho, Er, Yb. The isoquinoline-2-oxide complexes analyse for the formula $Ln(IsoQNO)_7(ClO_4)_3$ where Ln = La-Yb.

  3. Synthesis and structural studies of some trivalent lanthanide complexes of isonicotinic acid hydrazide

    International Nuclear Information System (INIS)

    Trivalent lanthanides have been found to form complexes with isonicotinic acid hydrazide (INH) of the type M(INH)3X3 [X=Cl, SCN; M=La(III), Pr(III), Nd(III), Sm(III) and Gd(III)]. The complexes have been characterized by elemental analysis, molar conductance, magnetic susceptibility, infrared and electronic spectral studies. The nephelauxetic ratio (β), covalency (δ) and bonding parameter (b1/1) have been calculated from the electronic spectra. Infrared spectral studies reveal that INH acts as a neutral bidentate chelating ligand in all the complexes and that thiocyanate is N-bonded. (author)

  4. Lanthanide metal complex-based membrane electrodes for sensing of biological amino alcohols

    International Nuclear Information System (INIS)

    Electrodes selective for amino alcohols were prepared by incorporating lanthanide tris(β-diketonates) in PVC membranes, which formed 1:1 highly coordinated complexes with amino alcohols. Several electrodes gave near-Nernstian slopes for 2-amino-3-methyl-1-butanol in the linear concentration range of 1.0 x 10-1 to 1.0 x 10-3 M, while the low detection limits of these electrodes were order of ∼10-4 M. Although the observed response profiles were significantly dependent on the natures of the targeted amino alcohols, the electrodes exhibited stable potentiometric signals in the pH range of 6-12 in short time period of 20 s. The related monoalcohol, diol, and zwitterionic amino acid substrates gave no response, indicating that the present type of lanthanide tris(β-diketonates) were applicable in potentiometric sensing of amino alcohols

  5. Preparation of photoluminescent PMMA doped with tris(pyrazol-1-yl)borate lanthanide complexes

    Energy Technology Data Exchange (ETDEWEB)

    Bortoluzzi, Marco, E-mail: markos@unive.it [Dipartimento di Scienze Molecolari e Nanosistemi, Universita Ca' Foscari di Venezia, Dorsoduro 2137, 30123 Venezia (Italy); Paolucci, Gino, E-mail: paolucci@unive.it [Dipartimento di Scienze Molecolari e Nanosistemi, Universita Ca' Foscari di Venezia, Dorsoduro 2137, 30123 Venezia (Italy); Gatto, Mattia; Roppa, Stefania [Dipartimento di Scienze Molecolari e Nanosistemi, Universita Ca' Foscari di Venezia, Dorsoduro 2137, 30123 Venezia (Italy); Enrichi, Francesco [CIVEN, Coordinamento Interuniversitario Veneto per le Nanotecnologie, Via delle Industrie 5, 30175 Marghera (Venezia) (Italy); Ciorba, Serena; Richards, Bryce S. [School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS (United Kingdom)

    2012-09-15

    The neutral homoleptic Ln(III) complex Ln(Tp){sub 3} (Ln=Sm, Eu, Tb, Yb; Tp=hydrotris(pyrazol-1-yl)borate) were used as dopants for the preparation of novel photoluminescent poly(methyl methacrylate) glasses indicated as Ln(Tp){sub 3}-PMMA. The doped polymers containing samarium, europium and terbium derivatives showed emission associated to f-f transitions in the visible range upon excitation with UV light, while a NIR emission was obtained from Yb(Tp){sub 3}-PMMA. The maximum incident wavelength able to induce emissions from the Ln(Tp){sub 3}-doped polymers depends upon the choice of the lanthanide ion. No meaningful antenna-effect was instead observed using dysprosium as metal centre. - Highlights: Black-Right-Pointing-Pointer Polymers doped with photoluminescent lanthanide complexes. Black-Right-Pointing-Pointer Hydrotris(pyrazol-1-yl)borate (Tp) as antenna-ligand for Sm(III), Eu(III), Tb(III) and Yb(III). Black-Right-Pointing-Pointer Emission associated to f-f transitions upon excitation with UV light. Black-Right-Pointing-Pointer No antenna-effect for dysprosium derivative. Black-Right-Pointing-Pointer Photoluminescence excitation spectra are dependent upon the lanthanide ion.

  6. Uranyl-Lanthanide Hetero-metallic Complexes with Cucurbit[6]uril and Perrhenate Ligands

    International Nuclear Information System (INIS)

    The reaction of uranyl and lanthanide nitrates with cucurbit[6]uril (CB6) in the presence of perrhenic acid and under hydrothermal conditions yields the novel hetero-metallic uranyl-lanthanide molecular complexes [UO2Ln(CB6)(ReO4)2(NO3)(H2O)7](ReO4)2 (Ln = Sm, Eu, Gd, Lu). Both metal cations are bound to carbonyl groups of the same CB6 portal, one for UO22+ and two for Ln3+. The uranium atom is also bound to one monodentate perrhenate ion and three aquo ligands, while the lanthanide is bound to one monodentate perrhenate and one nitrate ions, and four aquo ligands. Not only are these complexes rare examples of ReO4- bonding to f element ions, but the perrhenate bound to Ln is included in the CB6 cavity, thus providing the first case of inclusion of a tetrahedral oxo-anion in this macrocycle. (author)

  7. Lanthanide-humic substances complexation. II. Calibration of humic ion-binding model V

    Energy Technology Data Exchange (ETDEWEB)

    Jeroen E. Sonke [CNRS/IRD/Universite Paul Sabatier Toulouse III, Toulouse (France). Laboratoire des Mecanismes et Transferts en Geologie

    2006-12-15

    The experimental complexation of the lanthanides (Sc, Y, and rare earth elements) with Suwannee river fulvic acid, Leonardite coal humic acid, and Elliot soil humic acid is described with Humic Ion-Binding Model V. The fitted intrinsic equilibrium constants for metal-proton exchange, pK{sub MHA}, for Eu{sup 3+} are similar to previously published experimental fits, and linear free energy relationship (LFER) estimated values. The experimentally observed lanthanide contraction effect in REE-humic complex stability is reflected in the gradual decrease in pK{sub MHA} from La to Lu. In Model V, a decrease in pK{sub MHA} from La to Lu indicates an increase in complex stability. Fitted pK{sub MHA} values for heavy REE are lower than those estimated by LFERs. Consequently, REE fractionation by humic substances complexation could be more pronounced than previously thought. Recommended pK{sub MHA} values for lanthanide-fulvic and -humic acid complexation are derived by superimposing the fitted trends in pK{sub MHA} for all REE, i.e., the decrease in pK{sub MHA} from La to Lu, on the average Eu pK{sub MHA} value for all literature datasets. These results will allow modeling assessments of organic matter induced REE fractionation in aquatic environments, taking into account changes in pH, ionic strength, and ion competition. A simulation of dissolved REE speciation in an average world river suggests that organic matter out competes carbonate complexation, even under alkaline conditions. 48 refs., 4 figs., 3 tabs.

  8. New sandwich-type lanthanide complexes based on closed-macrocyclic Schiff base and phthalocyanine molecules.

    Science.gov (United States)

    Gao, Feng; Feng, Xiaowan; Yang, Liu; Chen, Xiaoyu

    2016-04-25

    Two new sandwich-type lanthanide complexes with the general formula [(Pc)2Ln3(L)(OAc)(OCH3)2] (Ln(3+) = Dy(3+) () and Er(3+) ()) were successfully synthesized and structurally characterized based on closed-macrocyclic Schiff base and phthalocyanine molecules. The magnetic properties and structure-property relationship in this multi-decker system were investigated. Interestingly, the corresponding dysprosium complex shows typical single-molecule magnetic behavior with ferromagnetic dipole-dipole interactions and the slow relaxation of magnetization. PMID:27044594

  9. Stability constants of lanthanide(3) ions complexes with 8-hydroxyquinoline and its derivatives

    International Nuclear Information System (INIS)

    The change of successive stability constants of lanthanide ion complexes with 8-hydroxyquinoline and its derivatives: 5,7-dinitro-, 5,7-dichloro-, 5,7-dibromo-, 5,7-diiodo- and halo-5-sulfonic acids: 7-bromine- and 7-iodine-, is considered. Diagrams of lg K dependence of Ln3+ complexes on the number of f-electrons has the most spread form: increase of lg K values with Nsub(f) increase is observed, ''godolinium fracture'' is clearly manifested. When passing from stability constants of the complexes with the ratio of components 1:1 to the complexes with the ratio 1:2 and 1:3 α-coefficient value in the equation for lg K decrease, i. e. contribution of electron number Nsub(f) to stability of the given type complexes decreases. Contributions of the number of f-electrons of lanthanide trivalent ions as well as those of spin and orbital momenta of the main states to the values of stability constants of their complexes with 8-hydroxyquinoline and its derivatives are manifested in a certain regularity

  10. Studies on the extraction of lanthanide complexes with 8-hydroxyquinoline

    International Nuclear Information System (INIS)

    The solvent extraction of Sm(III) and Eu(III) by 8-hydroxyquinoline (HOx) in chloroform from aqueous and polar aqueous-methanol phase has been studied as a function of pH(pHx) and the concentration of HOx or methanol in the organic phase. The extraction equilibrium constants (Kex,1 and Kex,2), two phase stability constants (β3x) for the Sm(Ox)3 and Eu(Ox)3 complexes, pH0.5, pH0.5x and separation factor SEu-Sm have been evaluated. (author). 22 refs, 5 figs, 2 tabs

  11. Fabrication of a lanthanide complex with specific magnetic and optical properties

    International Nuclear Information System (INIS)

    Aiming at control of molecular structure of lanthanide complexes, generally difficult owing to the large coordination number and also to the complexity coming from variation in ionic radius called lanthanide contraction, the authors synthesized a series of the rare earth (from La to Yb) complexes having a redox-active ligand, [Ln(aminoquinone)2(Otf)3] where Otf=CF3SO3-, and investigated the change in magnetic and optical properties with varying central metals. Neutral complexes were prepared by designing the ligand coordinating to metal through three atoms, 2,3-diaminonaphthoquinone neutralized by triethylamine in acetonitrile, further treated with La trifluoromethane-sulfonate. The structure was confirmed by X-ray crystallography with bond length estimated. Coordination structural change with changing central metal was studied in view of ionic radius of metal. One-electron reduction of the ligand was studied with Ln=La, Ga, and Yb, the interaction of the resulting organic radical with f-electron of the metal studied by ESR. Magnetic susceptibility was measured as function of temperature and discussed from the molecular structural view point. (S. Ohno)

  12. Application of Δ- and Λ-Isomerism of Octahedral Metal Complexes for Inducing Chiral Nematic Phases

    Directory of Open Access Journals (Sweden)

    Hisako Sato

    2009-10-01

    Full Text Available The Δ- and Λ-isomerism of octahedral metal complexes is employed as a source of chirality for inducing chiral nematic phases. By applying a wide range of chiral metal complexes as a dopant, it has been found that tris(β-diketonatometal(III complexes exhibit an extremely high value of helical twisting power. The mechanism of induction of the chiral nematic phase is postulated on the basis of a surface chirality model. The strategy for designing an efficient dopant is described, together with the results using a number of examples of Co(III, Cr(III and Ru(III complexes with C2 symmetry. The development of photo-responsive dopants to achieve the photo-induced structural change of liquid crystal by use of photo-isomerization of chiral metal complexes is also described.

  13. AFM reconstruction of complex-shaped chiral plasmonic nanostructures

    CERN Document Server

    Kondratov, Alexey V; Gainutdinov, Radmir V

    2016-01-01

    A significant part of the optical metamaterial phenomena has the plasmonic nature and their investigation requires very accurate knowledge of the fabricated structures shape with a focus on the periodical features. We describe a consistent approach to the shape reconstruction of the plasmonic nanostructures. This includes vertical and tilted spike AFM probes fabrication, AFM imaging and specific post-processing. We studied a complex-shaped chiral metamaterial and conclude that the described post-processing routine extends possibilities of the existing deconvolution algorithms in the case of periodical structures with known rotational symmetry, by providing valuable information about periodical features.

  14. Chiral de Rham complex on special holonomy manifolds

    CERN Document Server

    Ekstrand, Joel; Kallen, Johan; Zabzine, Maxim

    2010-01-01

    Interpreting the chiral de Rham complex (CDR) as a formal Hamiltonian quantization of the supersymmetric non-linear sigma model, we suggest a setup for the study of CDR on manifolds with special holonomy. We discuss classical and partial quantum results. As a concrete example, we construct two commuting copies of the Odake algebra (an extension of the N=2 superconformal algebra) on the space of global sections of CDR of a Calabi-Yau 3-fold. This is the first example of such a vertex subalgebra which is non-linearly generated by a finite number of superfields.

  15. Studies of inclusion complexes between cyclodextrins and polyazamacrocyclic chelates of lanthanide (III) ions

    International Nuclear Information System (INIS)

    The complexes between γ-cyclodextrin and lanthanide (III) chelates of the polyazamacrocycles DOTA (DOTA ≡ 1,4,7,10-tertraazacyclododecane-1,4,7,10-tetraacetate) and DOTP (DOTP ≡ 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetramethylenephosphonate) have been thought out to enhance the potential of such chelates as contrast agents for MRI. Given the actual demand for the design of new contrast agents, we thought it worthwhile to confirm previous results for the equilibrium constant K obtained by one of us by NMR on the DOTP complex, as well as to determine K for a new one with DOTA. Further, we wanted to study and quantify the interactions present in these complexes, with a view to improve them in newly designed complexes. The interactions between γ-cyclodextrin and the lanthanide (III)-polyazamacrocyclic chelates, [Tm(DOTP)]5-, and [Gd(DOTA)]- were then studied by isothermal calorimetry (ITC) and molecular dynamics. The calorimetric experiments can be interpreted by considering that in both cases there is a weak association, characterized by low values for the equilibrium constant as well as for the molar enthalpy change for complex formation, at T=298.15 K. The K value for the complex with DOTP obtained now by ITC is of the same order of magnitude of the one determined previously by NMR. Further, the complex formation seems rather insensitive to the macrocycle, as the values now obtained by ITC for the DOTA complex are very similar to the ones obtained for the DOTP complex. We have also carried out molecular dynamics simulations on these very same inclusion complexes, which provided quantitative data on the interactions present, as well as a plausible explanation for the data obtained, leading to the proposal of possible solutions to improve the modelling of new contrast agents on a host-guest basis

  16. Studies of inclusion complexes between cyclodextrins and polyazamacrocyclic chelates of lanthanide (III) ions

    OpenAIRE

    Henriques, Elsa S.; Bastos, Margarida; Geraldes, Carlos F. G. C.; Ramos, Maria João

    2003-01-01

    The complexes between [gamma]-cyclodextrin and lanthanide (III) chelates of the polyazamacrocycles DOTA (DOTA [reverse not equivalent] 1,4,7,10-tertraazacyclododecane-1,4,7,10-tetraacetate) and DOTP (DOTP [reverse not equivalent] 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetramethylenephosphonate) have been thought out to enhance the potential of such chelates as contrast agents for MRI. Given the actual demand for the design of new contrast agents, we thought it worthwhile to confirm previous ...

  17. Fluorescence of lanthanide(3) complexes with aminopolyacetic acids in aqueous solutions

    International Nuclear Information System (INIS)

    The fluorescence of Eu(3), Gd(3), Tb(3) and Dy(3) ions complexed with aminopolyacetic acids was investigated. The influence of temperature and the dimensions of the ligand molecules and of their electric charge on the intensity of the emission bands is discussed as well as the ratio of the hypersensitive (forbidden) band to the allowed band intensity. On the basis of the fluorescence measurements a simple theoretical model is discussed and certain generalizations concerning the fluorescence of the lanthanides group are derived. (Author)

  18. Homoleptic 2-mercapto benzothiazolate uranium and lanthanide complexes

    International Nuclear Information System (INIS)

    Treatment of [Ln(BH4)3(THF)3] (Ln = Ce, Nd) with 3 and 4 mol equiv of KSBT in tetrahydrofuran (THF) led to the formation of [Ln(SBT)3(THF)] and [K(THF)Ln(SBT)4], respectively. The uranium(IV) compound [U(SBT)4(THF)2] was obtained from U(BH4)4 and was reversibly reduced by sodium amalgam into the corresponding anionic uranium(III) complex. The crystal structures of [Ln(SBT)3(THF)2] (Ln = Ce, Nd), [K(15-crown-5)2][Nd(SBT)4], [U(SBT)4(THF)], and [K(15-crown-5)2][U(SBT)4(py)] show the bidentate coordination mode and the thionate character of the SBT ligand. (authors)

  19. Studies on the extraction of lanthanide complexes with 8-quinolinol

    International Nuclear Information System (INIS)

    The solvent extraction of Dy(3), Er(3), Yb(3) and Lu(3) by 8-quinolinol (HOx) in CHCl3 from aqueous and polar aqueous-methanol phase has been studied as a function of pH(pHx) or the concentration of HOx in the organic phase. The data suggest that the equation for the extraction reaction from the aqueous phase is Ln(H2O)y(aq)3+ + 3HOx(o)↔ LnOx3(o) + 3H(aq)+ + yH2O where: Ln = Dy, Er, Yb. The extraction equilibrium constants of reaction, two-phase stability constants for the DyOx3, ErOx3 and YbOx3 complexes, pH 0.5, pH0.5x and separation factor have been evaluated. Methanol causes a synergistic effect. 3 figs., 1 tab. 33 refs. (author)

  20. Synthesis and resolution of Planar-Chiral Ruthenium-Palladium complexes with ECE pincer ligands

    NARCIS (Netherlands)

    Bonnet, S.A.; Li, J.; Siegler, M.A.M.; von Chrzanowski, L.S.; Spek, A.L.; van Koten, G.; Klein Gebbink, R.J.M.

    2009-01-01

    Feel the pinch! Planar-chiral, cationic, ruthenium-palladium complexes based on 6,1-coordinated ECE pincer ligands are synthesized as racemic mixtures by reacting ECE-palladium complexes and [Ru(C5R5)(MeCN)3]+ arenophiles (R=H or Me). Chiral resolution of the cationic complexes was achieved by using

  1. Characterization of partitioning relevant lanthanide and actinide complexes by NMR spectroscopy

    International Nuclear Information System (INIS)

    In the present work the interaction of N-donor ligands, such as 2,6-Bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine (nPrBTP) and 2,6-Bis(5-(2,2-dimethylpropyl)1H-pyrazol)-3-yl-pyridine (C5-BPP), with trivalent lanthanide and actinide ions was studied. Ligands of this type show a high selectivity for the separation of trivalent actinide ions over lanthanides from nitric acid solutions. However, the reason for this selectivity, which is crucial for future partitioning and transmutation strategies for radioactive wastes, is still unknown. So far, the selectivity of some N-donor ligands is supposed to be an effect of an increased covalency in the actinide-ligand bond, compared to the lanthanide compounds. NMR spectroscopy on paramagnetic metal complexes is an excellent tool for the elucidation of bonding modes. The overall paramagnetic chemical shift consists of two contributions, the Fermi Contact Shift (FCS), due to electron spin delocalisation through covalent bonds, and the Pseudo Contact Shift (PCS), which describes the dipolar coupling of the electron magnetic moment and the nuclear spin. By assessing the FCS share in the paramagnetic shift, the degree of covalency in the metal-ligand bond can be gauged. Several methods to discriminate FCS and PCS have been used on the data of the nPrBTP- and C5-BPP-complexes and were evaluated regarding their applicability on lanthanide and actinide complexes with N-donor ligands. The study comprised the synthesis of all Ln(III) complexes with the exceptions of Pm(III) and Gd(III) as well as the Am(III) complex as a representative of the actinide series with both ligands. All complexes were fully characterised (1H, 13C and 15N spectra) using NMR spectroscopy. By isotope enrichment with the NMR-active 15N in positions 8 and 9 in both ligands, resonance signals of these nitrogen atoms were detected for all complexes. The Bleaneymethod relies on different temperature dependencies for FCS (T-1) and PCS (T-2) that occur upon description

  2. Theoretical prediction of the structure and electronic spectra of lanthanide complexes

    International Nuclear Information System (INIS)

    Full text: The strategy adopted by our group to design complexes of lanthanide ions as efficient light-conversion molecular devices (LCMD) is based upon both experimental and theoretical approaches, investigating a large number of different Eu(III), Tb(III) and Gd(III) complexes. In this paper, we report studies on the complexes Ln(3-NH2pic)3phen, [Eu(III) or Gd(III)], 3-NH2pic = acid 3-amino-2- pyridinecarboxylic and phen 1,10-phenanthroline. The complexes were characterized by elemental analysis, infrared, UV-Visible and NMR and also through spectroscopic measurements of luminescence spectra and lifetime. The triplets and singlets positions for the ligands were obtained from the gadolinium complex spectrum at low temperature (77K). The calculations for the europium complex were conducted through the following procedure: geometry was obtained by optimization with the SMLC/AM1 model implemented in the MOPAC program; and singlets and triplets levels and electronic spectra were computed with the INDO/S-CI technique using the ZINDO program. The coordination polyhedron for the predicted ground state geometry of the europium complex presented a distorted square antiprism structure due to the presence of the negatively charged carboxylic oxygen atoms. The comparison between theoretical (18034 cm-1) and experimental (18868 cm-1) triplet positions shows a good agreement. The electronic spectrum evidence is in good agreement with the experimental one. The ultimate aim of our work is to use these predictive tools to design ligands, which will form stable complexes that will function as efficient 'LCMD'. Such complexes should have strong ligand-centred absorption in the UV region, efficient ligand to lanthanide energy transfer rates and intense metal-centred emission in the visible range: red to Eu(III) and green for Tb(III)

  3. Experimentation and modelling of U, Th, and lanthanides transport in fissured rocks. Influence of complexation

    International Nuclear Information System (INIS)

    A circulation between two drill holes in a granite after hydraulic fracturation (site INAG, le Mayet de Montagne, France) is experimented. UO2(CO3)34- and Th, La, Sm, Eu, Dy and Yb EDTA complexes are injected together. Different amounts of tracers are also inpected successively. Break through curves are similar for Th and Lanthanides, but somewhat different for U that shows increasing tailing. Recovery rates increase with increasing stability of the complex (41.4% for La to 96.7% for Yb in the third run) and with increasing amount of tracer. To account for indications of non linearity, a Freundlich isotherms: F=K.Csup(1/2), C= complexed tracer concentration in the fluid, F= tracers concentration adsorbed on the solid, K= global sorption constant, is used for EDTA tracer sorption. The experiments have demonstrated the importance of complexation and its consequence (non linearity) when experimenting and modelling elements transport

  4. Synthesis, Characterization and Fluorescence of Phenylcarboxymethyl Sulfoxide Complexes with Lanthanide Nitrates

    Institute of Scientific and Technical Information of China (English)

    李文先; 张东凤

    2002-01-01

    Phenylcarboxymethyl Sulfoxide, PhSOCH2COOH(LH), complexes of six lanthanide nitrates: Ln2L2(NO3)4*2LH*nH2O(where Ln=La, Ce, Pr, Nd, Sm, Eu) were synthesized. Elemental analyses, molar conductivities, IR, 1HNMR and TG-DTA measurements were used to characterize the complexes. The results show that the ligand(L) is coordinated to metal ions through two oxygen atoms of the carboxyl group and one oxygen atom of the sulfoxide moieties. Neutral ligang (LH)is coordinated to two metal ions through two oxygen atoms of carboxyl group as an asymmetrical bridging bidentate. The fluorescence spectra of Eu3+ complex indicates that there is no inversion symmetry at the site of Eu3+ ion, but the emission intensity of fluorescence is quite good.The solubility of the complexes is very good in water.

  5. Application of lanthanide complexes for the purification of di-isobutyl-sulfoxide

    International Nuclear Information System (INIS)

    A new procedure for the purification of sulfoxides based on the selective precipitation of their complexes with class (a) metallic ions is reported. A commercial sample of di-isobutylsulfoxide containing about 5 - 10% of the corresponding sulfone was purified by precipitation with lanthanide perchlorates from alcoholic solutions. The recovery of the sulfoxide from the solid complex was accomplished by dissolving the complex in water and extracting the sulfoxide with chloroform. Alternatively the aqueous solution of the complex was passed successively through columns containing strongly acidic cation-exchanger resin in the H-cycle and strongly basic anionic-exchanger in the OH-cycle. T.L.C. homogeneous sulfoxide was obtained simply by evaporation of the solvent at reduced pressure. (Author)

  6. Complexation of Lanthanides with Nitrate at Variable Temperatures: Thermodynamics and Coordination Modes

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Linfeng; Tian, Guoxin

    2008-12-10

    Complexation of neodymium(III) with nitrate was studied at variable temperatures (25, 40, 55 and 70 C) by spectrophotometry and microcalorimetry. The NdNO{sub 3}{sup 2+} complex is weak and becomes slightly stronger as the temperature is increased. The enthalpy of complexation at 25 C was determined by microcalorimetry to be small and positive, (1.5 {+-} 0.2) kJ {center_dot} mol{sup -1}, in good agreement with the trend of the stability constant at variable temperatures. Luminescence emission spectra and lifetime of Eu(III) in nitrate solutions suggest that inner-sphere and bidentate complexes form between trivalent lanthanides (Nd{sup 3+} and Eu{sup 3+}) and nitrate in aqueous solutions. Specific Ion Interaction approach (SIT) was used to obtain the stability constants of NdNO{sub 3}{sup 2+} at infinite dilution and variable temperatures.

  7. Study of the factors supporting the selective complexation of the trivalent lanthanide and actinide ions; Etude des facteurs favorisant la complexation selective des ions lanthanides et actinides trivalents

    Energy Technology Data Exchange (ETDEWEB)

    Mehdoui, T

    2005-09-15

    In order to obtain clear-cut information on the factors which favour the discrimination between trivalent actinides and lanthanides, we investigated the complexation of the tris(cyclopentadienyl) Ce(III) and U(III) compounds, (RCp)3M (R = tBu, SiMe3), with a series of monocyclic azines with distinct Lewis basicity and reduction potential. Coordination of pyrazine and 4,4' and 2,2'-bipyridines on the (RCp)3M complexes has also been studied. Of major interest is the reversible oxidation of the (RCp)3U species into the uranium(IV) [(RCp)3U]2(pyz) complexes by pyrazine. The presence of cooperativity in the binding of the cyclopentadienyl groups by U(III), due to late appearance of back-bonding, leads to a greater stabilization of the uranium(III) complexes. Complexation of the species Cp*2MI (M = Ce, U) by 2,2'-bipyridine, phenanthroline and ter-pyridine affords the adducts [Cp*2M(L)]I. For L = bipy and terpy, these compounds are reduced into Cp*2M(L). The magnetic data for [Cp*2M(terpy)]I and Cp*2M(terpy) are consistent with Ce(III) and U(III) species, with the formulation Cp*2MIII(terpy). An electron transfer reaction between these species was observed in NMR. Reactions of the [Cp*2M(terpy)]I and Cp*2M(terpy) complexes with H and H{sup +} donor reagents lead to a clear differentiation of these trivalent ions. We studied the coordination of the stable N-heterocyclic carbene and isonitrile molecules on (RCp)3M and Cp*2MI; competition reactions and comparison of the crystal structures of the carbene compounds reveal the much better affinity of the NHC and tBuNC ligands for the 5f rather than for the 4f ion. (authors)

  8. Lanthanide metal-organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Peng (ed.) [Nankai Univ., Tianjin (China). Dept. of Chemistry

    2015-03-01

    This book contains the following nine chapters: lanthanide metal-organic frameworks: syntheses, properties, and potential applications (Stephen Fordham, Xuan Wang, Mathieu Bosch, Hong-Cai Zhou); 2. chiral lanthanide metal-organic frameworks (Weisheng Liu, Xiaoliang Tang); 3. Porous lanthanide metal-organic frameworks for gas storage and separation (Bin Li, Banglin Chen); 4. Luminescent lanthanide metal-organic frameworks (Xue-Zhi Song, Shu-Yan Song, Hong-Jie Zhang); 5. Metal-organic frameworks based on lanthanide clusters (Lian Chen, Feilong Jiang, Kang Zhou, Mingyan Wu, Maochun Hong); 6. metal-organic frameworks with d-f cyanide bridges: structural diversity, bonding regime, and magnetism (Marilena Ferbinteanu, Fanica Cimpoesu, Stefania Tanase); 7. transition-lanthanide heterometal-organic frameworks: synthesis, structures, and properties (Wei Shi, Ke Liu, Peng Cheng); 8: MOFs of uranium and the actinides (Juan Su, Jiesheng Chen); 9. Nanostructured and/or nanoscale lanthanide metal-organic frameworks (Zhonghao Zhang, Zhiping Zheng).

  9. Lanthanide metal-organic frameworks

    International Nuclear Information System (INIS)

    This book contains the following nine chapters: lanthanide metal-organic frameworks: syntheses, properties, and potential applications (Stephen Fordham, Xuan Wang, Mathieu Bosch, Hong-Cai Zhou); 2. chiral lanthanide metal-organic frameworks (Weisheng Liu, Xiaoliang Tang); 3. Porous lanthanide metal-organic frameworks for gas storage and separation (Bin Li, Banglin Chen); 4. Luminescent lanthanide metal-organic frameworks (Xue-Zhi Song, Shu-Yan Song, Hong-Jie Zhang); 5. Metal-organic frameworks based on lanthanide clusters (Lian Chen, Feilong Jiang, Kang Zhou, Mingyan Wu, Maochun Hong); 6. metal-organic frameworks with d-f cyanide bridges: structural diversity, bonding regime, and magnetism (Marilena Ferbinteanu, Fanica Cimpoesu, Stefania Tanase); 7. transition-lanthanide heterometal-organic frameworks: synthesis, structures, and properties (Wei Shi, Ke Liu, Peng Cheng); 8: MOFs of uranium and the actinides (Juan Su, Jiesheng Chen); 9. Nanostructured and/or nanoscale lanthanide metal-organic frameworks (Zhonghao Zhang, Zhiping Zheng).

  10. Elucidating the radical kinetics involved in the radiolytic destruction of lanthanide-complexed DTPA

    International Nuclear Information System (INIS)

    The reprocessing of nuclear fuels to extract the remaining actinides is one of the most important strategies for viable nuclear power in the future, as geologic waste disposal of high-level radioactive waste could have considerable negative impacts on the environment. As many of these strategies are based on solvent extraction processes, our aim is to establish the radiolytic stability of the component extraction ligands. The oxidative stability of the lanthanide metal-complexed extraction ligand DTPA (diethylenetriaminepentaacetic acid) has been investigated through its reaction rate constant with the hydroxyl radical under TALSPEAK acidic pH conditions, both for the free ligand and complexed with Eu3+, Lu3+ and Gd3+. Specific rate constants were obtained over a range of pH conditions using thiocyanate competition kinetics. The rate constants for the complexed metals are seen to be greater than the corresponding values determined for only the DTPA protonated ligands at these pHs. (author)

  11. NMR studies of lanthanide (III) nitrate complexes in CMPO/TBP systems

    International Nuclear Information System (INIS)

    We have studied the TRUEX process, which partitions actinides from HLLW (high level liquid wastes) for minimization of environmental load during the management and disposal of HLLW. In the TRUEX process, CMPO is used as an extractant and TBP as a phase modifier. In this study, coordination properties of light lanthanides (Ln) complexes in the CMPO/TBP systems were investigated by NMR measurements, leading to a deeper understanding of the extraction mechanism of these elements in the TRUEX process. We clarified the structure of the Ln complexes, their changes with CMPO concentration, and the effect of TBP on the Ln complexes in the CMPO/TBP systems. We will use these fundamental data to optimize and improve the TRUEX process. (author)

  12. Lanthanide-cyclodextrin complexes as probes for elucidating optical purity by NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wenzel, T.J.; Bogyo, M.S.; Lebeau, E.L. (Bates College, Lewiston, ME (United States))

    1994-06-01

    A multidentate ligand is bonded to cyclodextrins by the reaction of diethylenetriaminepentaacetic dianhydride with 6-mono- and 2-mono(ethylenediamine) derivatives of cyclodextrin. Adding Dy(III) to the cyclodextrin derivatives enhances the enantiomeric resolution in the [sup 1]H NMR spectra of carbionoxamine maleate, doxylamine succinate, pheniramine maleate, propranolol hydrochloride, and tryptophan. The enhancement is more pronounced with the secondary derivative. The Dy(III)-induced shifts can be used to elucidate the geometry of cyclodextrin-substrate inclusion complexes. Lanthanide-induced shifts are reported for complexes of aspartame, tryptophan, propranolol, and 1-anilino-8-naphthalenesulfonate with cyclodextrins, and the relative magnitudes of the shifts agree with previously reported structures of the complexes. 37 refs., 9 figs., 5 tabs.

  13. Synthesis, Characterization, and Reactivity of Amine Bis(phenolato) Cyclopentadienyl Lanthanide Complexes

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    (C5H5)3Ln(THF) reacted with amine bis(phenol) LH2[L=Me2NCH2CH2N{CH2-(2-O-C6H2-But-3-Me-5)}2] in a 1:1 molar ratio in THF to generate the amine bis(phenolato) cyclopentadienyl lanthanide complexes LLn(C5H5)(THF)·(THF)n (Ln=La (1), n=0; Ln=Sm(2), n=1) in high yields. Complexes 1 and 2 were fully characterized by elemental analysis, NMR (for 1) and IR spectra, and X-ray structural determination. The crystal data of complex 1 are monoclinic, P21/c space group, a=1.1595(1) nm, b=1.8588(2) nm, c=1.6647(1) nm, β= 98.490(2)°, V=3.5486(5) nm3, Z=4, Dc=1.338 mg·m-3, μ=1.240 mm-1, F(000)=1488, R=0.0249, wR=0.0568. The crystal data of complex 2 are monoclinic, P21/c space group, a=0.9692(1) nm, b=1.4583(2) nm, c=2.8192(3) nm, β=96.805(2)°, V=3.9584(7) nm3, Z=4, Dc=1.340 mg·m-3, μ=1.524 mm-1, F(000)=1668, R=0.0346, wR=0.0756. The attempts failed to synthesize the amine bis(phenolate) lanthanide alkoxides by the reactions of complexes 1 and 2 with alcohols. The preliminary results revealed that complex 1 can initiate ε-caprolactone polymerization.

  14. Acetato-bridged dinuclear lanthanide complexes with single molecule magnet behaviour for the Dy2 species.

    Science.gov (United States)

    Zhang, Haixia; Lin, Shuang-Yan; Xue, Shufang; Wang, Chao; Tang, Jinkui

    2014-04-28

    Five dinuclear lanthanide complexes with formula [Ln2L2(OAc)4(MeOH)a(H2O)b] · cMeOH · dH2O (a = 2, b = 0, c = 2, d = 0, Ln = Sm (1), Gd (2), Dy (3); a = 0, b = 2, c = 4, d = 2, Ln = Tm (4)) and [Yb2L2(OAc)4(MeOH)2]·[Yb2L2(OAc)4(H2O)2] · 2H2O (5) (HL = (E)-N'-(2-hydroxybenzylidene)-2-mercaptonicotinohydrazide), have been synthesized and their crystal structures and magnetic properties are reported. All five complexes are centrosymmetric, showing a similar dinuclear core with two lanthanide ions in each complex being bridged by acetate groups in the η(1):η(2):μ2 mode. The various coordination modes of acetate groups result in two kinds of coordination geometries for Ln ions with the ones in complexes 1-4 and the Yb2 in 5 being nine-coordinated with a mono-capped square antiprism geometry, while the Yb1 ions in the other part of complex 5 are eight-coordinated with a triangular dodecahedron geometry. Magnetic susceptibility studies reveal that complex 3 shows single molecule magnet behaviour with an energy barrier of 39.1 K. In addition, comparison of the structural parameters among the similar Dy2 SMMs with a η(1):η(2):μ2 coordination mode of carboxylate groups reveals the significant role played by coordination geometry in modulating the relaxation dynamics of SMMs. PMID:24599563

  15. Lanthanides(III)/Actinides(III) separation by nano-filtration-complexation

    International Nuclear Information System (INIS)

    The aim of this work is to evaluate the lanthanides (III) separation by nano-filtration complexation according to the pH (1.0-4.0) with poly-amino-carboxylic acids as complexing agent. The experimental Ln(III) complex rejections were then compared to Ln(III)-Ligand system speciation calculated using the protonation and thermodynamic stability constants. Some differences were revealed for lower (pH 1.0) and higher (pH 4.0) Ln(III) complex rejections. These differences of the Ln(III) complex rejections could be explained by a combination of both steric exclusion and surface force interactions. At pH 1.0, the initial experimental rejection of the free Ln(III) reaches 6% in absence of complexation because the membrane is positively charged. In order to limit the escape in Ln(III) complexes at pH 4.0, the influence of the operating parameters was studied. At pH 5.8 and for an operational pressure of 3 bars, a complex concentration of 0.4 mM, a tangential velocity of 145 mm.s-1 and a temperature of 15 deg C, the Gd(III) complex rejection reached more than 99% and thus the total Gd(III) complex in the feed is rejected. (authors)

  16. Synthesis and Thermal Behaviour of Lanthanide Complexes of 4′[(Cholesteryloxy)Carbonyl]—Benzo—15—Crown—5

    Institute of Scientific and Technical Information of China (English)

    KoenBinnemans; BilgiCuendogan

    2002-01-01

    Lanthanide complexes of a steroid-substituted benzocrown ether were synthesised.The metal-to-ligand ratio of the metal complexes is1:1,The ligand4′[(Cholesteryloxy)Carbonyl]-Benzo-15-Crown-5 is a monotropicliquid crystal,displaying a cholesteric mesophase.The lanethanide complexes with nitate counter-ions form a highly viscous mesophase,decomposing at the clearing point ,The transition temperatures change as a function of the lanthanide ion.The corresponding lanthanide complexes with dodecylsulphate(DOS)counter-ions do not form a mesophase,In both cases ,the metal complexes have a much lower melting point than the parent ligand.

  17. Radiochemical extraction of lanthanide thiocyanate complexes with bis-2-ethylhexyl sulphoxide

    International Nuclear Information System (INIS)

    The extraction of lanthanides (Ln) such as Nd(III), Eu(III) and Er(III) from thiocyanate solutions by bis-2-ethylhexyl sulphoxide (B2EHSO) in benzene has been studied by tracer techniques. For comparison, extraction studies have been carried out with di-n-octyl sulphoxide (DOSO) and tri-octyl phosphine oxide (TOPO). Extraction studies have also been carried out with mixtures of B2EHSO and DOSO or TOPO. A relatively small synergistic enhancement has been observed with a mixture of extractants, which may be due to the formation of more stable mixed-ligand complexes. The extraction data have been analysed by both graphical and theoretical methods taking into account aqueous phase speciation and all plausible complexes extracted into the organic phase. The equilibrium constants of the extracted species were determined by non-linear regression analysis. (orig.)

  18. Formation constants of some ternary lanthanide complexes with o-phenanthroline and aliphatic amino acids

    International Nuclear Information System (INIS)

    The values of formation constants of ternary complexes may be influenced by direct or indirect cooperative effects between the two ligands simultaneously bonded to the metal ion. In the case of lanthanide(III) metal ions the variation in formation constant values over the Ln(III) series may also be affected by the occurrence of tetrad effect or double-double effect. The present communication is intended to report the trends in formation constants of the ternary Ln(III) complexes of the type [Ln(III) phen.L], where Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy or Er; phen=o-phenanthroline; L=glycine, α-alanine, valine or leucine. (author). 13 refs., 1 tab

  19. Sub-monolayer film growth of a volatile lanthanide complex on metallic surfaces

    Directory of Open Access Journals (Sweden)

    Hironari Isshiki

    2015-12-01

    Full Text Available We deposited a volatile lanthanide complex, tris(2,2,6,6-tetramethyl-3,5-heptanedionatoterbium(III, onto metal surfaces of Cu(111, Ag(111 and Au(111 in vacuum and observed well-ordered sub-monolayer films with low temperature (5 K scanning tunneling microscopy. The films show a distorted three-fold symmetry with a commensurate structure. Scanning tunneling spectroscopy reveals molecular orbitals delocalized on the ligands of the molecule. Our results imply that this complex can be transferred onto the metal substrates without molecular decomposition or contamination of the surface. This new rare-earth-based class of molecules broadens the choice of molecular magnets to study with scanning tunneling microscopy.

  20. A complex-polarization-propagator protocol for magneto-chiral axial dichroism and birefringence dispersion

    DEFF Research Database (Denmark)

    Cukras, Janusz; Kauczor, Joanna; Norman, Patrick;

    2016-01-01

    A computational protocol for magneto-chiral dichroism and magneto-chiral birefringence dispersion is presented within the framework of damped response theory, also known as complex polarization propagator theory, at the level of time-dependent Hartree–Fock and time-dependent density functional th...... circular dichroism. The additional information content yielded by the magneto-chiral phenomena, as well as their potential experimental detectability for the selected species, is discussed....

  1. Solvent phase characterization of lanthanide and americium complexes with malonamide and ter-pyridine ligands. Comparison with single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Den Auwer, C.; Grigoriev, M.S.; Charbonnel, M.C.; Presson, M.T. [CEA/VALRHO - site de Marcoule, Dept. de Recherche en Retraitement et en Vitrification, DRRV, 30 - Marcoule (France); Den Auwer, C. [Laboratoire pour l' Utilisation du Rayonnement Electromagnetique (LURE), Paris-11 Univ., 91 - Orsay (France); Grigoriev, M.S. [Institute of Physical Chemistry, Russian Academy of Sciences, Moscow (Russian Federation)

    2000-07-01

    This work presents our latest results on the coordination polyhedron of the tetranitrate lanthanide complexes with aza and carboxy ligands. Structures in the solid state have been determined by X-ray single crystal diffraction and solution studies have been carried out by X-ray Absorption Spectroscopy at the cation L{sub III} edge. Comparison is made with the Am cation. (authors)

  2. Solvent phase characterization of lanthanide and americium complexes with malonamide and ter-pyridine ligands. Comparison with single crystals

    International Nuclear Information System (INIS)

    This work presents our latest results on the coordination polyhedron of the tetranitrate lanthanide complexes with aza and carboxy ligands. Structures in the solid state have been determined by X-ray single crystal diffraction and solution studies have been carried out by X-ray Absorption Spectroscopy at the cation LIII edge. Comparison is made with the Am cation. (authors)

  3. Structural variability in uranyl-lanthanide hetero-metallic complexes with DOTA and oxalato ligands

    International Nuclear Information System (INIS)

    Four novel 4f-5f hetero-metallic complexes could be obtained from the reaction of uranyl and lanthanide nitrates with DOTA (H4L) under hydrothermal conditions. In all cases, as in the previous examples reported, additional oxalato ligands are formed in situ. Variations in the stoichiometry of the final products and the presence of hydroxo ions in some cases appear to result in a large structural variability. In the two isomorphous complexes [(UO2)2Ln2(L)2(C2O4)] with Ln = Sm(1) or Eu(2), the lanthanide ion is located in the N4O4 site and is also bound to a carboxylate oxygen atom from a neighbouring unit, to give zigzag chains which are further linked to one another by [(UO2)2(C2O4)]2+ di-cations, resulting in the formation of a 3D framework. In [(UO2)4Gd2(L)2(C2O4)3(H2O)6].2H2O (3), 2D bilayer subunits of the 'double floor' type with uranyl oxalate pillars are assembled into a 3D framework by other, disordered uranyl ions. [(UO2)2Gd(L)(C2O4)(OH)].H2O (4) is a 2D assembly in which cationic {[(UO2)2(C2O4)(OH)]+}n chains are linked to one another by the [Gd(L)]- groups. The most notable feature of this compound is the environment of the 4f ion, which is eight-coordinate and twisted square anti-prismatic (TSA'), instead of nine-coordinate mono-capped square anti-prismatic (SA), as generally observed in DOTA complexes of gadolinium(III) and similarly-sized ions. (author)

  4. H4octapa: highly stable complexation of lanthanide(III) ions and copper(II).

    Science.gov (United States)

    Kálmán, Ferenc Krisztián; Végh, Andrea; Regueiro-Figueroa, Martín; Tóth, Éva; Platas-Iglesias, Carlos; Tircsó, Gyula

    2015-03-01

    The acyclic ligand octapa(4-) (H4octapa = 6,6'-((ethane-1,2-diylbis((carboxymethyl)azanediyl))bis(methylene))dipicolinic acid) forms stable complexes with the Ln(3+) ions in aqueous solution. The stability constants determined for the complexes with La(3+), Gd(3+), and Lu(3+) using relaxometric methods are log KLaL = 20.13(7), log KGdL = 20.23(4), and log KLuL = 20.49(5) (I = 0.15 M NaCl). High stability constants were also determined for the complexes formed with divalent metal ions such as Zn(2+) and Cu(2+) (log KZnL = 18.91(3) and log KCuL = 22.08(2)). UV-visible and NMR spectroscopic studies and density functional theory (DFT) calculations point to hexadentate binding of the ligand to Zn(2+) and Cu(2+), the donor atoms of the acetate groups of the ligand remaining uncoordinated. The complexes formed with the Ln(3+) ions are nine-coordinated thanks to the octadentate binding of the ligand and the presence of a coordinated water molecule. The stability constants of the complexes formed with the Ln(3+) ions do not change significantly across the lanthanide series. A DFT investigation shows that this is the result of a subtle balance between the increased binding energies across the 4f period, which contribute to an increasing complex stability, and the parallel increase of the absolute values of the hydration free energies of the Ln(3+) ions. In the case of the [Ln(octapa)(H2O)](-) complexes the interaction between the amine nitrogen atoms of the ligand and the Ln(3+) ions is weakened along the lanthanide series, and therefore the increased electrostatic interaction does not overcome the increasing hydration energies. A detailed kinetic study of the dissociation of the [Gd(octapa)(H2O)](-) complex in the presence of Cu(2+) shows that the metal-assisted pathway is the main responsible for complex dissociation at pH 7.4 and physiological [Cu(2+)] concentration (1 μM). PMID:25692564

  5. DISTRIBUTION OF LANTHANIDE AND ACTINIDE ELEMENTS BETWEEN BIS-(2-ETHYLHEXYL)PHOSPHORIC ACID AND BUFFERED LACTATE SOLUTIONS CONTAINING SELECTED COMPLEXANTS

    Energy Technology Data Exchange (ETDEWEB)

    Rudisill, Tracy S.; Diprete, David P.; Thompson, Major C.

    2013-04-15

    With the renewed interest in the closure of the nuclear fuel cycle, the TALSPEAK process is being considered for the separation of Am and Cm from the lanthanide fission products in a next generation reprocessing plant. However, an efficient separation requires tight control of the pH which likely will be difficult to achieve on a large scale. To address this issue, we measured the distribution of lanthanide and actinide elements between aqueous and organic phases in the presence of complexants which were potentially less sensitive to pH control than the diethylenetriaminepentaacetic (DTPA) used in the process. To perform the extractions, a rapid and accurate method was developed for measuring distribution coefficients based on the preparation of lanthanide tracers in the Savannah River National Laboratory neutron activation analysis facility. The complexants tested included aceto-, benzo-, and salicylhydroxamic acids, N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), and ammonium thiocyanate (NH{sub 4}SCN). The hydroxamic acids were the least effective of the complexants tested. The separation factors for TPEN and NH{sub 4}SCN were higher, especially for the heaviest lanthanides in the series; however, no conditions were identified which resulted in separations factors which consistently approached those measured for the use of DTPA.

  6. Distribution Of Lanthanide And Actinide Elements Between BIS-(2-Ethylhexyl)Phosphoric Acid And Buffered Lactate Solutions Containing Selected Complexants

    International Nuclear Information System (INIS)

    With the renewed interest in the closure of the nuclear fuel cycle, the TALSPEAK process is being considered for the separation of Am and Cm from the lanthanide fission products in a next generation reprocessing plant. However, an efficient separation requires tight control of the pH which likely will be difficult to achieve on a large scale. To address this issue, we measured the distribution of lanthanide and actinide elements between aqueous and organic phases in the presence of complexants which were potentially less sensitive to pH control than the diethylenetriaminepentaacetic (DTPA) used in the process. To perform the extractions, a rapid and accurate method was developed for measuring distribution coefficients based on the preparation of lanthanide tracers in the Savannah River National Laboratory neutron activation analysis facility. The complexants tested included aceto-, benzo-, and salicylhydroxamic acids, N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), and ammonium thiocyanate (NH4SCN). The hydroxamic acids were the least effective of the complexants tested. The separation factors for TPEN and NH4SCN were higher, especially for the heaviest lanthanides in the series; however, no conditions were identified which resulted in separations factors which consistently approached those measured for the use of DTPA

  7. Synthesis and spectral studies of some lanthanide complexes with tridentate thiosemicarbazone ligand

    International Nuclear Information System (INIS)

    Lanthanide complexes of the type ((Cl)2Ln(L)(H2O)4) and ((Cl)Ln(L)2(H2O)3) (where Ln= Nd(III), Gd(III), Sm(III) and Y(III), L= Schiff base ligand; salicylidene-thiosemicarbazide (stscH)) were synthesized and characterized by various physico-chemical techniques. The complexes were found to be coloured solid and were highly soluble in methanol, ethanol, DMF and DMSO. These complexes have been characterized by elemental (Ln, C, H, N, S and Cl) analysis and spectral (IR, 1H- and 13C-NMR) data, whereas the structure of the complexes has been tentatively determined by FAB-MS spectral studies. X-ray powder diffraction of one of the complex was recorded on Rigaku Model D/Max-2200 PC using Cu-Kα1 radiation (λ = 1.5406 Å). The crystallite size of the complex ((Cl)2Gd(L)(H2O)4) is 193.04 Å. (author)

  8. Theoretical study of the structure and reactivity of lanthanide and actinide based organometallic complexes; Etude theorique de la structure et de la reactivite de complexes organometalliques de lanthanides et d'actinides

    Energy Technology Data Exchange (ETDEWEB)

    Barros, N

    2007-06-15

    In this PhD thesis, lanthanide and actinide based organometallic complexes are studied using quantum chemistry methods. In a first part, the catalytic properties of organo-lanthanide compounds are evaluated by studying two types of reactions: the catalytic hydro-functionalization of olefins and the polymerisation of polar monomers. The reaction mechanisms are theoretically determined and validated, and the influence of possible secondary non productive reactions is envisaged. A second part focuses on uranium-based complexes. Firstly, the electronic structure of uranium metallocenes is analysed. An analogy with the uranyl compounds is proposed. In a second chapter, two isoelectronic complexes of uranium IV are studied. After validating the use of DFT methods for describing the electronic structure and the reactivity of these compounds, it is shown that their reactivity difference can be related to a different nature of chemical bonding in these complexes. (author)

  9. Solvent extraction of the lanthanide elements, scandium, uranium and thorium using tetracycline as complexing agent

    International Nuclear Information System (INIS)

    The scope of the work is to extend the study of the solvent extraction behaviour to all the 15 lanthanide elements as well as to uranium and thorium and to study the application of the system tetracycline-benzyl alcohol for the separation of the mentioned elements. pH dependence of the extraction have been determined. The effect of the presence of a supporting electrolyte (NaCl) on the extraction as well as the effect of ageing of the extractant solution on its extractant properties were studied. The variation of distribution ratio with metal concentration was examined in order to verify whether or not polynuclear complexes were present in the conditions under which the work was performed. In the first case discontinuous counter-current technique was used. In the second case a single step solvent extraction procedure was applied. (T.G.)

  10. Complex formation of the lanthanides and actinides in lower oxidation states

    International Nuclear Information System (INIS)

    The coordination chemistry of the lanthanides (ln) and actinides (An) in lower oxidation states is discussed, including the hydration-solvation properties of Ln2+ and An2+ in aqueous and aqueous-ethanolic solutions and the formation of complexes with the tetraphenylborate ion and crown ethers. Some physicochemical properties of a number of novel compounds with crown ethers are reported. In this paper the difference in the properties of Ln2+ and An2+ with an fnd0 and fn-1d1 configuration and the ability of the fn-1 d1 compounds to form mixed condensed clusters with Gd2Cl3 are discussed. The properties of Ln and An elements in various oxidation states are compared with those of elements of other groups in the periodic table

  11. Influence of metal ion hydrolysis on the determination of complex stability constants as shown by lanthanide complexes of α-amino acids

    International Nuclear Information System (INIS)

    The conventional potentiometric methods for the determination of stability constants disregard the hydrolysis as a competing reaction for complex formation of cations, such as lanthanides. Two different ways for recording the metal hydrolysis are shown. It is assumed on appropriate conditions that only the first complex is formed. (author)

  12. Chiral holmium complex-catalyzed Diels-Alder reaction of silyloxyvinylindoles: stereoselective synthesis of hydrocarbazoles.

    Science.gov (United States)

    Harada, Shinji; Morikawa, Takahiro; Nishida, Atsushi

    2013-10-18

    The catalytic and asymmetric cycloaddition between 3-[1-(silyloxy)vinyl]indoles and electron-deficient olefins gave substituted hydrocarbazoles in up to 99% yield and 94% ee. This reaction was catalyzed by a novel chiral holmium(III) complex. Alkylation of the cycloadduct gave a tricyclic compound with four continuous chiral centers, one of which was a quaternary carbon. PMID:24079531

  13. Stability constants of mixed ligand complexes of lanthanide(III) and yttrium(III) with complexone and substituted salicylic acids

    International Nuclear Information System (INIS)

    Salicylic acid and substituted salicylic acids are potential antimicrobial agents. Binary complexes of salicylic acid and its substituted derivatives with lanthanide(III) and yttrium(III) metal ions have been reported. There are reports on the ternary metal complexing equilibria with some lanthanide(III) and yttrium(III) metal ions involving aminopolycarboxylic acid as one ligand and salicylic acid (SA) and other related compounds as the second ligands. Ethylene glycol bis(2-aminoethylether)- N, N, N', N'-tetraacetic acid (EGTA) is an important member of aminopolycarboxylic acid and finds many applications in medicine and biology. Recently, few ternary complexes have been reported using EGTA as ligand. In view of biological importance of simple and mixed ligand complexes EGTA, SA and DNSA (3,5-dinitrosalicylic acid), a systematic study has been undertaken for the determination of stability constant and the results are reported. (author). 6 refs., 1 fig., 2 tabs

  14. Anion Effects on Lanthanide(III) Tetrazole-1-acetate Dinuclear Complexes Showing Slow Magnetic Relaxation and Photofluorescent Emission.

    Science.gov (United States)

    Lu, Ying-Bing; Jiang, Xiao-Ming; Zhu, Shui-Dong; Du, Zi-Yi; Liu, Cai-Ming; Xie, Yong-Rong; Liu, Liang-Xian

    2016-04-18

    Three types of lanthanide complexes based on the tetrazole-1-acetic acid ligand and the 2,2'-bipyridine coligand were prepared and characterized by single-crystal X-ray diffraction, IR spectroscopy, and elemental analyses; the formulas of these complexes are [Ln2(1-tza)4(NO3)2(2,2'-bipy)2] (Ln = Sm (1), Eu (2), Gd (3), Tb (4), Dy (5)), [Dy2(1-tza)4Cl2(2,2'-bipy)2] (6), and [Yb2(1-tza)4(NO3)2(2,2'-bipy)2] (7) (1-tza = tetrazole-1-acetate and 2,2'-bipy = 2,2'-bipyridine). They are dinuclear complexes possessing similar structures but different lanthanide(III) ion coordination geometries because of the distinction of peripheral anions (such as NO3(-) and Cl(-)) and the effect of lanthanide contraction. The variable-temperature magnetic susceptibilities of 1-6 were measured. Both Dy(III) complexes (5 and 6) display field-induced single-molecule magnet behaviors. Ab initio calculations revealed that the Dy(III) complex 6 possesses a more anisotropic Dy(III) ion in comparison to that in 5. The room-temperature photoluminescence spectra of Sm(III) (1), Eu(III) (2), Tb(III) (4), and Dy(III) (5 and 6) complexes exhibit strong characteristic emissions in the visible region, whereas the Yb(III) (7) complex shows near-infrared (NIR) luminescence. PMID:27023680

  15. Chiral PEPPSI Complexes: Synthesis, Characterization, and Application in Asymmetric Suzuki–Miyaura Coupling Reactions

    KAUST Repository

    Benhamou, Laure

    2014-01-13

    PEPPSI complexes incorporating chiral N-heterocyclic carbene (NHC) ligands based on 2,2-dimethyl-1-(o-substituted aryl)propan-1-amines were synthesized. Two complexes, with one saturated and one unsaturated NHC ligand, were structurally characterized. The chiral PEPPSI complexes were used in asymmetric Suzuki-Miyaura reactions, giving atropisomeric biaryl products in modest to good enantiomeric ratios. © 2013 American Chemical Society.

  16. Synthesis, Structural Characterization, and Chiroptical Studies of Bidentate Salen-Type Lanthanide (III) Complexes.

    Science.gov (United States)

    Berardozzi, Roberto; Pescitelli, Gennaro; Di Pietro, Sebastiano; Resta, Claudio; Ballistreri, Francesco P; Pappalardo, Andrea; Tomaselli, Gaetano A; Di Bari, Lorenzo

    2015-12-01

    The salen-type ligand prepared with (R,R) diphenylethan-1,2-diamine and salicylaldehyde provides stable and inert complexes KLnL2 upon simple reaction with lanthanide halides or pseudohalides LnX3 (Ln = Tb(3+) -Lu(3+) ; X = Cl(-) or TfO(-) ) of its potassium salt. All the complexes were completely characterized through nuclear magnetic resonance (NMR), electronic circular dichroism (ECD) in the UV and some (Er(3+) , Tm(3+) , Yb(3+) ) also with Near-IR ECD (NIR-ECD) and luminescence (Tb(3+) , Tm(3+) ). Careful analysis of the NMR shifts demonstrated that the complexes are isostructural in solution and afforded an accurate geometry. This was further confirmed by means of Density Functional Theory (DFT) optimization of the Lu(3+) complex, and by comparing the ligand-centered experimental and time-dependent TD-DFT computed UV-ECD spectra. As final validation, we used the NIR-ECD spectrum of the Yb(3+) derivative calculated by means of Richardson's equations. The excellent match between calculated and experimental ECD spectra confirm the quality of the NMR structure. PMID:26422601

  17. Near-IR luminescent lanthanide complexes with 1,8-diaminoanthraquinone-based chromophoric ligands.

    Science.gov (United States)

    Stacey, Oliver J; Ward, Benjamin D; Amoroso, Angelo J; Pope, Simon J A

    2016-04-12

    Three new chromophoric anthraquinone-based multidentate ligands have been synthesised in a step-wise manner from 1,8-dichloroanthraquinone. The ligands each comprise two dipicolyl amine units and react with trivalent lanthanide ions to form monometallic complexes of the form [Ln(L)](OTf)3 as indicated by MS studies and elemental analyses. Supporting DFT studies show that the monometallic species are highly favoured (>1000 kJ mol(-1)) over the formation of a 2 : 2 dimetallic congener. Both ligands and complexes absorb light efficiently (ε ∼ 10(4) M(-1) cm(-1)) in the visible part of the spectrum, with λabsca. 535-550 nm through an intramolecular charge transfer (ICT) transition localised on the substituted anthraquinone unit. In all cases the complexes show a fluorescence band at ca. 675 nm due to the ICT emitting state. The corresponding Nd(iii), Yb(iii) and Er(iii) complexes also reveal sensitised near-IR emission characteristic of each ion following excitation of the ICT visible absorption band at 535 nm. PMID:26974664

  18. Tuning a Lanthanide Complex To Be Responsive to the Environment in Solution.

    Science.gov (United States)

    Golkowski, Ryan T; Settineri, Nicholas S; Zhao, Xikang; McMillin, David R

    2015-12-01

    The f-f emissions of lanthanide-ion complexes have predictable emission energies and many practical applications, but the emitting states are generally impervious to the surroundings. This investigation explores ligand- and metal-centered emission processes for a series of mixed-ligand complexes of composition M(X-T)(NO3)3, where the metal ion is europium, gadolinium, terbium, or lutetium, and X-T denotes the tridentate ligand 2,2':6',2″-terpyridine (H-T), 4'-phenyl-2,2':6',2″-terpyridine (Ph-T), or 4'-pyrrolidin-N-yl-2,2':6',2″-terpyridine (pyrr-T). The presence of the pyrrolidinyl substituent imparts intraligand charge-transfer (ILCT) character to the ligand-based excited states and reduces the energy gap between the singlet and the triplet excited states. An enhanced rate of intersystem crossing results in a lutetium complex with a relatively small fluorescence quantum yield (0.15%) and a gadolinium complex with an impressive phosphorescence yield of 9.6% in deaerated solution. The Tb(pyrr-T)(NO3)3 system is unique because the relatively low-energy triplet ILCT state equilibrates with the emissive f-f state. The result is a truly remarkable f-f emission signal that is sensitive to the polarity of the local environment as well as the presence of dioxygen. PMID:26571330

  19. Complexes of (EtO)2P(O)CH2P(O)(OEt)2 with lanthanide nitrates

    International Nuclear Information System (INIS)

    The preparation of complexes of (EtO)2P(O)CH2P(O)(OEt)2 = L, with lanthanide nitrates is described. Stable complexes with composition LnL2(NO3)3 can be isolated for Ln = La-Eu and fully characterised. For LnGd-Lu solid compounds could not be isolated. Conductivity and 31P NMR spectroscopy indicate structural changes in solution between the lighter and heavier lanthanides and, whilst electro-spray mass spectrometry confirms a dramatic difference in behaviour with complexes of the heavier lanthanides readily decomposing via loss of EtNO3, other experiments show that this does not occur under the conditions of complex formation. The single crystal X-ray structures for Ln = La and Sm show the nitrates and OEt groups to be in close proximity. The changes in spectroscopic properties correlate well with the difficulties in isolating the complexes of heavier metals, and are possibly due to the formation of dimeric complexes rather than loss of ethyl nitrate. (authors)

  20. Relaxation process and phase transition of lanthanide liquid crystalline complexes by photoacoustic spectroscopy

    Institute of Scientific and Technical Information of China (English)

    LI Junjia; YANG Yuetao; LIU Xiaojun; ZHANG Shuyi; ZHANG Zhongning

    2008-01-01

    Lanthanide-containing liquid crystals exhibiting smectic A phase close to room temperature were obtained. Photoacoustic (PA) spectroscopy was used to study the spectral properties and phase transitions of liquid crystalline metal complexes. It was found that PA intensity of the ligand had a relationship with the probability of nonradiative transitions, which increased in the order of Eu(tta)3L2complexes were studied in depth from two aspects: radiative and non-radiative processes, combining with their fluorescence spectra. Phase transitions of europium(III) and erbium(III) complexes, in the temperature range of 383-358 K, could be clearly monitored by both PA amplitude and PA phase signals. As the temperature crossed the transition point, PA amplitude showed a minimum and PA phase a maximum. The results indicated that PA technique could serve as a new tool for investigating the physicochemical properties of liquid crystals containing metal ions.

  1. Lipophilic ternary complexes in liquid-liquid extraction of trivalent lanthanides

    Energy Technology Data Exchange (ETDEWEB)

    Lumetta, Gregg J.; Levitskaia, Tatiana G.; Latesky, Stanley; Henderson, Renesha V.; Edwards, Emilio A.; Braley, Jenifer C.; Sinkov, Sergey I.

    2012-03-01

    The formation of ternary complexes between lanthanide ions [Nd(III) or Eu(III)], octyl(phenyl)-N,N-diisobutyl-carbamoylmethylphosphine oxide (CMPO), and bis-(2-ethylhexyl)phosphoric acid (HDEHP) was probed by liquid-liquid extraction and spectroscopic techniques. Equilibrium modeling of data for the extraction of Nd(III) or Eu(III) from lactic acid media into n-dodecane solutions of CMPO and HDEHP indicates the predominant extracted species are of the type [Ln(AHA){sub 2}(A)] and [Ln(CMPO)(AHA){sub 2}(A)], where Ln = Nd or Eu and A represents the DEHP{sup -} anion. FTIR (for both Eu and Nd) and visible spectrophotometry (in the case of Nd) indicate the formation of the [Ln(CMPO)(A){sup 3}] complexes when CMPO is added to n-dodecane solutions of the LnA{sub 3} compounds. Both techniques indicate a stronger propensity of CMPO to complex Nd(III) versus Eu(III).

  2. Synthesis, Characterization, Luminescence and Biological Activity of Two Lanthanide Complexes Involving Mixed Ligands

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Deyun; Guo, Haifu; Qin, Liang [Zhaoqing Univ., Zhaoqing (China); Xu, Jun [Jinan Univ., Guangzhou (China)

    2013-09-15

    Two new isostructural dinuclear complexes, Ln{sub 2}(4-cpa){sub 6}(bpy){sub 2} (Ln = Eu (1); Tb (2), 4-cpa = 4-chlorophenyl-acetate, bpy = 2,2'-bipyridine), have been hydrothermally synthesized and characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis (TGA), powder X-ray diffraction and single-crystal X-ray diffraction. The lanthanide ions are bridged by two bidentate and two terdentate carboxylate groups to give centrosymmetric dimers with Ln···Ln separations of 3.967(2) and 3.956(3) A, respectively. Each metal atom is nine-coordinate and exhibits a distorted tricapped trigonal prismatic geometry. Three-dimensional fluorescence spectra show that both 1 and 2 emit bright red and green luminescence at room temperature, with long lifetimes of up to 0.369 ms (at 614 nm) and 0.432 ms (at 543 nm), respectively. Moreover, poor luminescence efficiency has been noted for complex 2. The 4-Hcpa ligand and complexes 1-2 have been screened for their phytogrowth-inhibitory activities against Brassica napus L. and Echinochloa crusgalli L., and the results are compared with the activity of quizalofop-P-ethyl.

  3. SYNTHESIS AND SPECTRAL-LUMINESCENT PROPERTIES OF CALIX[4]ARENES MODIFIED WITH CARBOXYLIC, PHTHALIMIDE AND AMINOETHOXY-GROUPS, AND THEIR LANTHANIDE-CONTAINING COMPLEXES

    OpenAIRE

    Fadeyev, Y. M.; Snurnikova, O. V.; Lukyanenko, O. P.; Alyeksyeyeva, O. O.; Rusakova, N. V.

    2015-01-01

    p-tert-Butylcalix[4]arene derivatives modified with carboxylic, phthalimide and aminoethoxy-groups on the lower rim as well as their lanthanide (ytterbium and lutetium) complexes were synthesized. Spectral-luminescent properties of obtained compounds were analyzed.

  4. Preparation for Supramolecular Complexes of Chiral Diols BDPDD, DMBDPD and BINOL with Some Prochiral Compounds

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Interaction between chiral diols BDPDD, DMBDPD and BINOL with prochiral compounds was examined and some new supramolecular complexes were prepared. It was found that these chiral hosts could include prochiral guests,α,β-unsaturated compounds or piper- azinedione derivatives to give inclusion crystals in different molar ratio. Formations of these supramolecular complexes were characterized by the data of IR and 1H NMR spectra.

  5. A chiral 6-membered N-heterocyclic carbene copper(I) complex that induces high stereoselectivity.

    Science.gov (United States)

    Park, Jin Kyoon; Lackey, Hershel H; Rexford, Matthew D; Kovnir, Kirill; Shatruk, Michael; McQuade, D Tyler

    2010-11-01

    A chiral 6-membered annulated N-heterocyclic (6-NHC) copper complex that catalyzes β-borylations with high yield and enantioselectivity was developed. The chiral 6-NHC copper complex is easy to prepare on the gram scale and is very active, showing 10,000 turnovers at 0.01 mol % of catalyst without significant decrease of enantioselectivity and with useful reaction rates. PMID:20919706

  6. Study of the factors supporting the selective complexation of the trivalent lanthanide and actinide ions

    International Nuclear Information System (INIS)

    In order to obtain clear-cut information on the factors which favour the discrimination between trivalent actinides and lanthanides, we investigated the complexation of the tris(cyclopentadienyl) Ce(III) and U(III) compounds, (RCp)3M (R = tBu, SiMe3), with a series of monocyclic azines with distinct Lewis basicity and reduction potential. Coordination of pyrazine and 4,4' and 2,2'-bipyridines on the (RCp)3M complexes has also been studied. Of major interest is the reversible oxidation of the (RCp)3U species into the uranium(IV) [(RCp)3U]2(pyz) complexes by pyrazine. The presence of cooperativity in the binding of the cyclopentadienyl groups by U(III), due to late appearance of back-bonding, leads to a greater stabilization of the uranium(III) complexes. Complexation of the species Cp*2MI (M = Ce, U) by 2,2'-bipyridine, phenanthroline and ter-pyridine affords the adducts [Cp*2M(L)]I. For L = bipy and terpy, these compounds are reduced into Cp*2M(L). The magnetic data for [Cp*2M(terpy)]I and Cp*2M(terpy) are consistent with Ce(III) and U(III) species, with the formulation Cp*2MIII(terpy). An electron transfer reaction between these species was observed in NMR. Reactions of the [Cp*2M(terpy)]I and Cp*2M(terpy) complexes with H and H+ donor reagents lead to a clear differentiation of these trivalent ions. We studied the coordination of the stable N-heterocyclic carbene and isonitrile molecules on (RCp)3M and Cp*2MI; competition reactions and comparison of the crystal structures of the carbene compounds reveal the much better affinity of the NHC and tBuNC ligands for the 5f rather than for the 4f ion. (authors)

  7. A complex-polarization-propagator protocol for magneto-chiral axial dichroism and birefringence dispersion.

    Science.gov (United States)

    Cukras, Janusz; Kauczor, Joanna; Norman, Patrick; Rizzo, Antonio; Rikken, Geert L J A; Coriani, Sonia

    2016-05-21

    A computational protocol for magneto-chiral dichroism and magneto-chiral birefringence dispersion is presented within the framework of damped response theory, also known as complex polarization propagator theory, at the level of time-dependent Hartree-Fock and time-dependent density functional theory. Magneto-chiral dichroism and magneto-chiral birefringence spectra in the (resonant) frequency region below the first ionization threshold of R-methyloxirane and l-alanine are presented and compared with the corresponding results obtained for both the electronic circular dichroism and the magnetic circular dichroism. The additional information content yielded by the magneto-chiral phenomena, as well as their potential experimental detectability for the selected species, is discussed. PMID:27118603

  8. Nanoparticles speckled by ready-to-conjugate lanthanide complexes for multimodal imaging

    Science.gov (United States)

    Biju, Vasudevanpillai; Hamada, Morihiko; Ono, Kenji; Sugino, Sakiko; Ohnishi, Takashi; Shibu, Edakkattuparambil Sidharth; Yamamura, Shohei; Sawada, Makoto; Nakanishi, Shunsuke; Shigeri, Yasushi; Wakida, Shin-Ichi

    2015-09-01

    Multimodal and multifunctional contrast agents receive enormous attention in the biomedical imaging field. Such contrast agents are routinely prepared by the incorporation of organic molecules and inorganic nanoparticles (NPs) into host materials such as gold NPs, silica NPs, polymer NPs, and liposomes. Despite their non-cytotoxic nature, the large size of these NPs limits the in vivo distribution and clearance and inflames complex pharmacokinetics, which hinder the regulatory approval for clinical applications. Herein, we report a unique method that combines magnetic resonance imaging (MRI) and fluorescence imaging modalities together in nanoscale entities by the simple, direct and stable conjugation of novel biotinylated coordination complexes of gadolinium(iii) to CdSe/ZnS quantum dots (QD) and terbium(iii) to super paramagnetic iron oxide NPs (SPION) but without any host material. Subsequently, we evaluate the potentials of such lanthanide-speckled fluorescent-magnetic NPs for bioimaging at single-molecule, cell and in vivo levels. The simple preparation and small size make such fluorescent-magnetic NPs promising contrast agents for biomedical imaging.

  9. Inorganic pigments doped with tris(pyrazol-1-yl)borate lanthanide complexes: A photoluminescence study

    Energy Technology Data Exchange (ETDEWEB)

    Gheno, Giulia, E-mail: giulia.gheno@unive.it [Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari di Venezia, Dorsoduro 2137, 30123 Venezia (Italy); Bortoluzzi, Marco; Ganzerla, Renzo [Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari di Venezia, Dorsoduro 2137, 30123 Venezia (Italy); Enrichi, Francesco [CIVEN, Coordinamento Interuniversitario Veneto per le Nanotecnologie, Via delle Industrie 5, 30175 Marghera, Venezia (Italy)

    2014-01-15

    The inorganic pigments malachite, Egyptian blue, Ercolano blue and chrome yellow have been doped with the neutral homoleptic Ln(III) complex Ln(Tp){sub 3} (Ln=Eu, Tb; Tp=hydrotris(pyrazol-1-yl)borate) in the presence of arabic gum or acrylic emulsion as binders, in order to obtain photoluminescent materials of interest for cultural heritage restoration. The doped pigments have shown emissions associated to f–f transitions in the visible range upon excitation with UV light. Thermal and UV-light ageings have been carried out. In all the cases the photoluminescent behaviour is maintained, but in the cases of acrylic-based paints emission spectra and lifetimes are strongly influenced by thermal treatments. The choice of binder and pigments influences the photoluminescent behaviour of the corresponding film paints. -- Highlights: • Inorganic pigments doped with photoluminescent lanthanide complexes. • Hydrotris(pyrazol-1-yl)borate (Tp) as antenna-ligand for Eu(III) and Tb(III). • Emission associated to f–f transitions upon excitation with UV light. • Photoluminescence of paints influenced by the choice of binder and pigments. • Photoluminescence after ageing depending upon the type of binder.

  10. Inorganic pigments doped with tris(pyrazol-1-yl)borate lanthanide complexes: A photoluminescence study

    International Nuclear Information System (INIS)

    The inorganic pigments malachite, Egyptian blue, Ercolano blue and chrome yellow have been doped with the neutral homoleptic Ln(III) complex Ln(Tp)3 (Ln=Eu, Tb; Tp=hydrotris(pyrazol-1-yl)borate) in the presence of arabic gum or acrylic emulsion as binders, in order to obtain photoluminescent materials of interest for cultural heritage restoration. The doped pigments have shown emissions associated to f–f transitions in the visible range upon excitation with UV light. Thermal and UV-light ageings have been carried out. In all the cases the photoluminescent behaviour is maintained, but in the cases of acrylic-based paints emission spectra and lifetimes are strongly influenced by thermal treatments. The choice of binder and pigments influences the photoluminescent behaviour of the corresponding film paints. -- Highlights: • Inorganic pigments doped with photoluminescent lanthanide complexes. • Hydrotris(pyrazol-1-yl)borate (Tp) as antenna-ligand for Eu(III) and Tb(III). • Emission associated to f–f transitions upon excitation with UV light. • Photoluminescence of paints influenced by the choice of binder and pigments. • Photoluminescence after ageing depending upon the type of binder

  11. Novel Lanthanide Complexes of Ciprofloxacin: Synthesis, Characterization, Crystal Structure and in vitro Antibacterial Activity Studies

    Institute of Scientific and Technical Information of China (English)

    LI,Jia-Bin; YANG,Pin; GAO,Fei; HAN,Gao-Yi; YU,Kai-Bei

    2001-01-01

    Novel lanthanide coordinatlon compounds with ciprofloxacin (CPFX), including eleven complexes Ln(CPFX)2Cl(H2O)n (Ln= Pr,Nd,Sm,Eu,Gd,To,Dy,Ho,Er,Tm, Yb; n =7,8, 9) and crystalline [Ce(CPFX)2(H2O)4]Cl· (H2O)3.25(C2H5- OH)0.25, were synthesized. The crystal is of triclinic space group Pi with a= 1.3865(2) nm, b = 1.3899(3) nm, c = 1.6505(2) nm, α= 92.73(1)°, β= 114.39(1)°, γ= 115.55 (1)°, Z = 2 and R = 0.0449.FT-IR, electronic spectroscopy and X-ray diffraction were employed to show that the lan thanide ion, which displays an eight-coordinate structure, is chelated by 3-carboxyl and 4-keto oxygen donors of CPFX and two six- membered chelate rings are formed. Test of in vitro antibacterial activity against E. coli, P. aeruginosa and S. aureus indicated that the in vitro antibacterial activity of the ligand can be improved by complexation with Ce(Ⅲ).

  12. Synthesis, X-ray crystal structure, DNA binding and Nuclease activity of lanthanide(III) complexes of 2-benzoylpyridine acetylhydrazone

    Indian Academy of Sciences (India)

    KARREDDULA RAJA; AKKILI SUSEELAMMA; KATREDDI HUSSAIN REDDY

    2016-08-01

    Lanthanide(III) complexes of general formula [La(BPAH)₂(NO₃)₃] and [Ce(BPAH)₂(NO₃)(H₂O)₂] 2NO₃.H₂O (where, BPAH = 2-benzoylpyridine acetyl hydrazone), were synthesized and characterized by elemental analysis, molar conductance, IR spectroscopy and single crystal X-ray diffraction and Hirschfeld studies. The central metal ion is 12-coordinate in lanthanum complex and 10-coordinated in the cerium complex. The coordination polyhedra around the lanthanum and cerium were found to have distorted icosahedron and distorted bicapped square antiprism respectively. DNA binding and nuclease activity of these complexes were also investigated in the present work.

  13. Evidence of different stoichiometries for the limiting carbonate complexes of lanthanides(3); Mise en evidence d'un changement de stoechiometrie du complexe carbonate limite au sein de la serie des lanthanides(3)

    Energy Technology Data Exchange (ETDEWEB)

    Philippini, V

    2007-12-15

    Two stoichiometries have been proposed by different laboratories to interpret measurements on the limiting carbonate complexes of An{sup 3+} and Ln{sup 3+} cations. The study of the solubility of double carbonates (AlkLn(CO{sub 3}){sub 2},xH{sub 2}O) in concentrated carbonate solutions at room temperature and high ionic strengths has shown that on the one hand the lightest lanthanides (La and Nd) form Ln(CO{sub 3}){sub 4}{sup 5-} whereas the heaviest (Eu and Dy) form Ln(CO{sub 3}){sub 3}{sup 3-} in the studied chemical conditions, and on the other hand, that the kinetics of precipitation of double carbonates depends on the alkali metal and the lanthanide ions. The existence of two stoichiometries for the limiting carbonate complexes was confirmed by capillary electrophoresis hyphenated to an inductively coupled plasma mass spectrometer (CE-ICP-MS), used to extend the study to the whole series of lanthanides (except Ce, Pm and Yb). Two behaviours have been put forward comparing the electrophoretic mobilities: La to Tb form Ln(CO{sub 3}){sub 4}{sup 5-} while Dy to Lu form Ln(CO{sub 3}){sub 3}{sup 3-}. Measurements by time resolved laser fluorescence spectroscopy (TRLFS) on Eu(III) indicate small variations of the geometry of Eu(CO{sub 3}){sub 3}{sup 3-} complex, specially with Cs{sup +}. Although analogies are currently used among the 4f-block trivalent elements, different aqueous speciations are evidenced in concentrated carbonate solutions across the lanthanide series. (author)

  14. Chirality at metal and helical ligand folding in optical isomers of chiral bis(naphthaldiminato)nickel(II) complexes.

    Science.gov (United States)

    Enamullah, Mohammed; Quddus, Mohammad Abdul; Hasan, Mohammad Rezabul; Pescitelli, Gennaro; Berardozzi, Roberto; Makhloufi, Gamall; Vasylyeva, Vera; Janiak, Christoph

    2016-01-14

    Enantiopure bis[{(R or S)-N-1-(Ar)ethyl-2-oxo-1-naphthaldiminato-κ(2)N,O}]nickel(ii) complexes {Ar = C6H5 ( or ), p-OMeC6H4 ( or ), and p-BrC6H4 ( or )} are synthesized from the reactions between (R or S)-N-1-(Ar)ethyl-2-oxo-1-naphthaldimine and nickel(ii) acetate. Circular-dichroism spectra and their density-functional theoretical simulation reveal the expected mirror image relationship between the enantiomeric pairs / and / in solution. CD spectra are dominated by the metal-centered Λ- or Δ-chirality of non-planar four-coordinated nickel, this latter being in turn dictated by the ligand chirality. Single crystal structure determination for and shows that there are two symmetry-independent molecules (A and B) in each asymmetric unit that give a Z' = 2 structure. Two asymmetric and chiral bidentate N^O-chelate Schiff base ligands coordinate to the nickel atom in a distorted square planar N2O2-coordination sphere. The conformational difference between the symmetry-independent molecules arises from the "up-or-down" folding of the naphthaldiminato ligand with respect to the coordination plane, which creates right- (P) or left-handed (M) helical conformations. Overall, the combination of ligand chirality, chirality at the metal and ligand folding gives rise to discrete metal helicates of preferred helicity in a selective way. Cyclic voltammograms (CV) show an oxidation wave at ca. 1.30 V for the [Ni(L)2]/[Ni(L)2](+) couple, and a reduction wave at ca. -0.35 V for the [Ni(L)2]/[Ni(L)2](-) couple in acetonitrile. PMID:26619269

  15. Aromatic Lateral Substituents Influence the Excitation Energies of Hexaaza Lanthanide Macrocyclic Complexes: A Wave Function Theory and Density Functional Study.

    Science.gov (United States)

    Rabanal-León, Walter A; Murillo-López, Juliana A; Páez-Hernández, Dayán; Arratia-Pérez, Ramiro

    2015-09-24

    The high interest in lanthanide chemistry, and particularly in their luminescence, has been encouraged by the need of understanding the lanthanide chemical coordination and how the design of new luminescent materials can be affected by this. This work is focused on the understanding of the electronic structure, bonding nature, and optical properties of a set of lanthanide hexaaza macrocyclic complexes, which can lead to potential optical applications. Here we found that the DFT ground state of the open-shell complexes are mainly characterized by the manifold of low lying f states, having small HOMO-LUMO energy gaps. The results obtained from the wave function theory calculations (SO-RASSI) put on evidence the multiconfigurational character of their ground state and it is observed that the large spin-orbit coupling and the weak crystal field produce a strong mix of the ground and the excited states. The electron localization function (ELF) and the energy decomposition analysis (EDA) support the idea of a dative interaction between the macrocyclic ligand and the lanthanide center for all the studied systems; noting that, this interaction has a covalent character, where the d-orbital participation is evidenced from NBO analysis, leaving the f shell completely noninteracting in the chemical bonding. From the optical part we observed in all cases the characteristic intraligand (IL) (π-π*) and ligand to metal charge-transfer (LMCT) bands that are present in the ultraviolet and visible regions, and for the open-shell complexes we found the inherent f-f electronic transitions on the visible and near-infrared region. PMID:26325624

  16. Thermal and spectroscopic studies on solid ibuprofen complexes of lighter trivalent lanthanides

    Energy Technology Data Exchange (ETDEWEB)

    Gálico, D.A.; Holanda, B.B.C.; Guerra, R.B.; Legendre, A.O.; Rinaldo, D. [UNESP – Univ Estadual Paulista, Faculdade de Ciências, Departamento de Química, São Paulo CEP 17033-260 (Brazil); Treu-Filho, O. [UNESP – Univ Estadual Paulista, Instituto de Química, São Paulo CEP 14800-900 (Brazil); Bannach, G., E-mail: gilbert@fc.unesp.br [UNESP – Univ Estadual Paulista, Faculdade de Ciências, Departamento de Química, São Paulo CEP 17033-260 (Brazil)

    2014-01-10

    Highlights: • Lighter trivalent lanthanide complexes of ibuprofen have been synthesized. • The TG-FTIR allowed the identification of propane as the gas evolved during the thermal decomposition of the neodymium compound. • The thermal analysis provided information about the composition, dehydration, thermal behavior and thermal decomposition of the samples. • The theoretical and experimental spectroscopic studies suggest that the carboxylate group of ibuprofen is coordinated to the metals by a bidentate bond. - Abstract: Solid-state compounds of general formula Ln(L){sub 3}, in which L is ibuprofen and Ln stands for trivalent La, Ce, Pr, Nd, Sm and Eu, have been synthesized. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), X-ray powder diffractometry (DRX), complexometry, Fourier-transformed infrared spectroscopy (FTIR) and thermogravimetry coupled to Fourier-transformed infrared spectroscopy (TG-FTIR) were used to characterize these compounds. The results provided information concerning the chemical composition, dehydration, coordination modes of the ligands, crystallinity of the samples, thermal behavior and thermal decomposition of the compounds. The theoretical and experimental spectroscopic studies suggest that ibuprofen coordinates through the carboxylate group as a chelating ligand.

  17. Thermal and spectroscopic studies on solid ibuprofen complexes of lighter trivalent lanthanides

    International Nuclear Information System (INIS)

    Highlights: • Lighter trivalent lanthanide complexes of ibuprofen have been synthesized. • The TG-FTIR allowed the identification of propane as the gas evolved during the thermal decomposition of the neodymium compound. • The thermal analysis provided information about the composition, dehydration, thermal behavior and thermal decomposition of the samples. • The theoretical and experimental spectroscopic studies suggest that the carboxylate group of ibuprofen is coordinated to the metals by a bidentate bond. - Abstract: Solid-state compounds of general formula Ln(L)3, in which L is ibuprofen and Ln stands for trivalent La, Ce, Pr, Nd, Sm and Eu, have been synthesized. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), X-ray powder diffractometry (DRX), complexometry, Fourier-transformed infrared spectroscopy (FTIR) and thermogravimetry coupled to Fourier-transformed infrared spectroscopy (TG-FTIR) were used to characterize these compounds. The results provided information concerning the chemical composition, dehydration, coordination modes of the ligands, crystallinity of the samples, thermal behavior and thermal decomposition of the compounds. The theoretical and experimental spectroscopic studies suggest that ibuprofen coordinates through the carboxylate group as a chelating ligand

  18. Tetrad effect in free energy changes of mixed ligand lanthanide-phenanthrdine-amino acid complexes

    International Nuclear Information System (INIS)

    The presence of tetrad effect has been investigated in the free energy changes accompanying the formation of lanthanide(III) mixed ligand complexes of the type [Ln(III). phen. L], where Ln(III)=La3+, Ce3+, Pr3+, Nd3+. Sm3+, Eu3+, Gd3+, Tb3+, Dy3+ or Er3+; phen= o-phenanthroline; L=histidine, β-phenyl alanine or tryptophan. The free energy changes Δ Gsub(MAL)sup(MA) have been computed from the formation constants log Ksub(MAL)sup(MA) determined pH-metrically by using, the Irving-Rossotti approach at 25degC and at ionic strength, I=0.2(mol dm-3, KNO3). The presence of tetrad effect has been demonstrated by Δ Gsub(MAL)sup(MA) vs 4fsup(n) plots, straight line approximation method, differential plot method and inclined W systematics. The magnitude of the effect has been found to lie in the sequence 4f7>4f3 - 4f4 ∼ 4f10 which constitutes an experimental evidence in favour of inter-electronic repulsion theory of tetrad effect. (author). 23 refs., 4 figs

  19. Separation and direct UV detection of complexed lanthanides, thorium and uranyl ions with 2-thenoyltrifluoroacetone by using capillary zone electrophoresis

    International Nuclear Information System (INIS)

    Separation and detection of lanthanides, thorium and uranyl ions by capillary zone electrophoresis in the presence of 2-thenoyltrifluoroacetone (HTTA) as UV-absorbing complexing agent were investigated. The separation of positively charged complexes is partially improved by using a competing ligand in buffer with HTTA for metal ions. When 2-hydroxyisobutyric acid (HIBA) is used as competing ligand, complete separation of thorium, uranyl and lanthanides ions were observed. Some separation parameters such as pH value, the concentration of carrier electrolyte, applied voltage, the concentration of ligand in buffer and the temperature were also optimized. Under the selected conditions, the complete separation of thorium and uranyl from each other and from lanthanides was accomplished in only 12 min using 1 mmol/L HTTA, 50 mmol/L HIBA, 5 mmol/L NaNO3, 5 % methanol with a pH 5.2 at a capillary temperature of 25 deg C. Direct photometric detection at 210 nm using a voltage of 25 kV and an electrokinetic injection (100 mm for 6 s) were used. (author)

  20. Mechanistic insights into the luminescent sensing of organophosphorus chemical warfare agents and simulants using trivalent lanthanide complexes.

    Science.gov (United States)

    Dennison, Genevieve H; Johnston, Martin R

    2015-04-20

    Organophosphorus chemical warfare agents (OP CWAs) are potent acetylcholinesterase inhibitors that can cause incapacitation and death within minutes of exposure, and furthermore are largely undetectable by the human senses. Fast, efficient, sensitive and selective detection of these compounds is therefore critical to minimise exposure. Traditional molecular-based sensing approaches have exploited the chemical reactivity of the OP CWAs, whereas more recently supramolecular-based approaches using non-covalent interactions have gained momentum. This is due, in part, to the potential development of sensors with second-generation properties, such as reversibility and multifunction capabilities. Supramolecular sensors also offer opportunities for incorporation of metal ions allowing for the exploitation of their unique properties. In particular, trivalent lanthanide ions are being increasingly used in the OP CWA sensing event and their use in supramolecular sensors is discussed in this Minireview. We focus on the fundamental interactions of simple lanthanide systems with OP CWAs and simulants, along with the development of more elaborate and complex systems including those containing nanotubes, polymers and gold nanoparticles. Whilst literature investigations into lanthanide-based OP CWA detection systems are relatively scarce, their unique and versatile properties provide a promising platform for the development of more efficient and complex sensing systems into the future. PMID:25649522

  1. Modeling of synthesis of borohydride lanthanides with auto initiations

    International Nuclear Information System (INIS)

    The mechanism of process of synthesis of lanthanide borohydrides interaction of lanthanide chlorides with sodium borohydride was investigated. The formation of dual-lanthanide complex with sodium borohydride was considered. The oscillatory nature of synthesis and initiation role of the lanthanide borohydride was shown. Polynomial for programmed synthesis of lanthanide borohydrides was composed.

  2. Thermodynamic study on the complexation of Trivalent actinide and lanthanide cation by N-donor ligands in homogeneous conditions; Etude thermodynamique de la complexation des ions actinide (III) et lanthanide (III) par des ligands polyazotes en milieu homogene

    Energy Technology Data Exchange (ETDEWEB)

    Miguirditchian, M

    2004-07-01

    Polydentate N-donor ligands, alone or combined with a synergic acid, may selectively extract minor actinides(III) from lanthanide(III) ions, allowing to develop separation processes of long-live radioelements. The aim of the researches carried out during this thesis was to better understand the chemical mechanisms of the complexation of f-elements by Adptz, a tridentate N-donor ligand, in homogeneous conditions. A thermodynamic approach was retained in order to estimate, from an energetic point of view, the influence of the different contributions to the reaction, and to acquire a complete set of thermodynamic data on this reaction. First, the influence of the nature of the cation on the thermodynamics was considered. The stability constants of the 1/1 complexes were systematically determined by UV-visible spectrophotometry for every lanthanide ion (except promethium) and for yttrium in a mixed solvent methanol/water in volume proportions 75/25%. The thermodynamic parameters ({delta}H{sup 0} {delta}{sup S}) of complexation were estimated by the van't Hoff method and by micro-calorimetry. The trends of the variations across the lanthanide series are compared with similar studies. The same methods were applied to the study of three actinide(III) cations: plutonium, americium and curium. The comparison of these values with those obtained for the lanthanides highlights the increase of stability of these complexes by a factor of 20 in favor of the actinide cations. This gap is explained by a more exothermic reaction and is associated, in the data interpretation, to a higher covalency of the actinide(III)-nitrogen bond. Then, the influence of the change of solvent composition on the thermodynamic of complexation was studied. The thermodynamic parameters of the complexation of europium(III) by Adptz were determined for several fractions of methanol. The stability of the complex formed increases with the percentage of methanol in the mixed solvent, owing to an

  3. Controlled chiral electrochromism of polyoxometalates incorporated in supramolecular complexes.

    Science.gov (United States)

    Zhang, Bin; Guan, Weiming; Zhang, Simin; Li, Bao; Wu, Lixin

    2016-04-01

    A three-component supramolecular system was constructed by combining host-guest recognition and electrostatic interaction for realization of induced circular dichroism of achiral polyanionic clusters in aqueous solution, while the induced chiral heteropoly blue was built and switched off by controlling the redox of the inorganic component via electrochemistry. PMID:27002653

  4. Pentamethylcyclopentadienyl and bis(trimethylsilyl)amido complexes of the di- and trivalent lanthanides

    International Nuclear Information System (INIS)

    The reaction of the divalent iodides YbI2 and EuI2 with NaN(SiMe3)2 has provided pentane-soluble, monomeric derivatives of the divalent lanthanides. These compounds are isolated as the solvated species Eu[N(SiMe3)2]2L2 (L = thf or 1,2-dme), Yb[N(SiMe3)2]2(thf)15 and Yb[N(SiMe3)2]2L2 (L = 1,2-dme or OEt2), or as the sodium salts NaM[N(SiMe3)2]3 (M = Eu or Yb). The pentamethylcyclopentadienyl ligand has been used to obtain trivalent derivatives of the type (C5Me5)2MCl2M'L/sub x/ (M = Nd, Sm or Yb; M' = Li or Na; L = OEt2 or tmed) or (C5Me5)2MCl(thf) (M = Nd or Yb). These compounds undergo metathesis reactions. The interaction of NaC5Me5 with EuCl3 yields only the divalent (C5Me5)2EuL (L = thf or OEt2). Analogous compounds of ytterbium are obtained by reaction of YbI2 with NaC5Me5 in thf or OEt2. The ytterbium amine complexes are weakly paramagnetic, apparently due to charge transfer from ytterbium to the aromatic rings. The divalent phosphine complexes (C5Me5)2ML (M = Eu or Yb; L = dmpe or dmpm) are also described. Crystallographic data are summarized

  5. Di-n-amyl L-tartrate-boric acid complex chiral selector in situ synthesis and its application in chiral nonaqueous capillary electrophoresis.

    Science.gov (United States)

    Wang, Li-Juan; Hu, Shao-Qiang; Guo, Qiao-Ling; Yang, Geng-Liang; Chen, Xing-Guo

    2011-03-01

    A chiral selector, di-n-amyl L-tartrate-boric acid complex, was in situ synthesized by the reaction of di-n-amyl L-tartrate with boric acid in a nonaqueous background electrolyte (BGE) using methanol as the medium. And a new method of chiral nonaqueous capillary electrophoresis (NACE) was developed with the complex as the chiral selector. It has been demonstrated that the chiral selector is suitable for the enantioseparation of some β-blockers and β-agonists in NACE. Some chiral analytes that could not be resolved in aqueous microemulsion electrokinetic chromatography (MEEKC) with the same chiral selector obtained baseline resolutions in the NACE system. The enantioseparation mechanism was considered to be ion-pair principle and the nonaqueous system was more favorable for the ion-pair formation which is quite useful for the chiral recognition. The addition of a proper concentration of triethylamine into the BGE to control the apparent pH (pH*) enhanced the enantiomeric discrimination. In order to achieve a good enantioseparation, the effects of di-n-amyl L-tartrate and boric acid concentration, triethylamine concentration, applied voltage, as well as capillary length were investigated. Under the optimum conditions, all of the tested chiral analytes including six β-blockers and five β-agonists were baseline resolved. PMID:21276972

  6. In situ synthesis of di-n-butyl l-tartrate-boric acid complex chiral selector and its application in chiral microemulsion electrokinetic chromatography.

    Science.gov (United States)

    Hu, Shaoqiang; Chen, Yonglei; Zhu, Huadong; Zhu, Jinhua; Yan, Na; Chen, Xingguo

    2009-11-01

    A novel procedure for in situ assembling a complex chiral selector, di-n-butyl l-tartrate-boric acid complex, by the reaction of di-n-butyl l-tartrate with boric acid in a running buffer was reported and its application in the enantioseparation of beta-blockers and structural related compounds by chiral microemulsion electrokinetic chromatography (MEEKC) has been demonstrated. In order to achieve a good enantioseparation, the effect of dibutyl l-tartrate and sodium tetraborate concentration, surfactant identity and concentration, cosurfactant, buffer pH and composition, organic modifiers, as well as applied voltage and capillary length were investigated. Ten pairs of enantiomers that could not be separated with only dibutyl l-tartrate, obtained good chiral separation using the complex chiral selector; among them, seven pairs could be baseline resolved under optimized experimental conditions. The fixation of chiral centers by the formation of five-membered rings, and being oppositely charged with basic analytes were thought to be the key factors giving the complex chiral selector a superior chiral recognition capability. The effect of the molecular structure of analytes on enantioseparation was discussed in terms of molecular interaction. PMID:19782374

  7. Electroluminescent and photophysical properties of near-infrared luminescent lanthanide(III) monoporphyrinate complexes and pendant polymers

    Science.gov (United States)

    Cunningham, Garry Brian

    The photoluminescent and electroluminescent properties of substituted lanthanide monoporphyrinate complexes were investigated. The lanthanide complexes consisted of a lanthanide (Yb3+) coordinated to a substituted porphyrin, 5,10,15,20-tetraphenylporphyrin (TPP), 5,10,15,20-tetrakis(3,4, 5-trimethoxyphenyl)porphyrin(TMPP), 5,10,15,20-tetra(4-pyridyl)porphyrin (TPyP), or 5,10,15,20-tetra(4(2'-ethylhexyloxy)porphyrin (TPP_OEH) and a capping ligand, L. The capping ligand was either an tris-pyrazoylborate (TP), (cyclopentadienyl)tris(diethoxyphosphito-P)cobaltate (L(OEt)3) or quinolinato (Q) anion. The complexes were synthesized to influence the electronic properties of the complex. The optical absorption and emission of these complexes resembled previously studied lanthanide porphyrin complexes, with photoluminescent yields ranging from 0.01 to 0.04. Electroluminescence was observed for the porphyrin complexes blended into polystyrene. External quantum efficiencies were typically 10-4, suggesting that changes to the porphyrin structure have little effect on the electronic nature of the complex. Blending the electron transporting AlQ3 into the device improved the external quantum efficiencies by an order of magnitude, suggesting that carrier transport is the culprit for poor device performance. Conjugated polyacetylenes containing a Zinc porphyrin pendant were synthesized by an insertion type polymerization using [Rh(NBD)Cl]2. The homopolymer (poly(ZnETPP) and copolymers of ethynyl benzene (poly(ZnETPP)-co-(PE)), an oxadiazole containing group (poly(ZnETPP)-co-(PEOXAD), or 1-ethynyl-3,5-trifluoromethylbenzene (poly(ZnETPP)-co-(3,5CF3PE) were synthesized. The optical properties were studied and it was found that the homopolymer exhibited excitonic coupling due to the overlap of the porphyrin pendants. Substitution of other co-monomers reduced this coupling allowing the return of typical ZnTPP optical properties. Neither absorption nor emission from the polyacetylene

  8. Synthesis, spectral and thermal studies of some lanthanide(III) complexes of 4-[N-(benzalidene) amino] antipyrine thiosemicarbazone

    International Nuclear Information System (INIS)

    A new series of sixteen lanthanide(III) complexes of 4[N-(benzalidene) amino] antipyrine thiosemicarbazone (BAAPTS) with the general composition LnX3.n(BAAPTS) (X =Cl-, n = 2; X = NO-3, n = 1; Ln = La, Pr, Nd, Sm, Gd, Tb, Dy and Ho) have been synthesized and characterized by chemical analysis, conductance, molar weight, magnetic moments measurements, infrared and electronic spectra. The ligand BAAPTS behaves as neutral tridentate (N, N, S) ligand. The probable coordination number is nine in these complexes. (author)

  9. Complexes of (III) lanthanides isothiocyanate and (III) yttrium with 2,6-lutidine-n-oxide (2,6-LNO)

    International Nuclear Information System (INIS)

    The preparation and characterization of the complexes of yttrium and some lanthanides isothiocyanate with 2,6-lutidine-N-oxide (2,6-LNO) are described. The ligand employed in the synthesis of the compounds were prepared by the reaction of 2,6-lutidine with hydrogen peroxide in glacial acetic acid. The complexes were prepared using the relation 1:3 salt-ligand. Their characterization was made by elemental analysis, electrolytic conductance measurements, X-ray powder patterns, infrared spectra, electronic absorption spectra of the neodymium and fluorescence spectra of the europium compounds. (author)

  10. A quantum chemistry study of actinide(III) and lanthanide(III) complexes with tridentate nitrogen ligands

    International Nuclear Information System (INIS)

    The structure and bonding in large complexes of actinide(III) and lanthanide(III) with tridentate N-donor ligands and water molecules have been investigated through quantum chemistry calculations in order to characterize the nature of the lanthanide-ligand and actinide-ligand bonds. Calculations have been performed using relativistic density functional theory on [M(L)(H2O)6]3+, [M(L)(H2O)5Cl]2+ and [M(H2O)9]3+ clusters where M = La, Ce, Nd, U, Pu, Am or Cm and L = 2,2':6'2''ter-pyridine (Terpy) or 2,6-bis(5,6-di-methyl-1,2,4-triazine-3-yl)pyridine (MeBtp). The calculated evolution of the M-L bond as a function of the cation shows that lanthanide-ligand distances decrease with the diminution of the ionic radius, whereas the actinide-ligand distances increase from uranium to americium and are shorter than Ln-N distances. These trends are explained by the presence of covalent effects in the metal-ligand decreasing in the order U > Pu > Am ≅ Cm ≅ Ln. (author)

  11. Trivalent lanthanide and actinide extraction by functionalized calixarenes study of the structure of complexes in solution by nuclear magnetic resonance

    International Nuclear Information System (INIS)

    The behaviour of different lanthanides and actinides with respect to their complexation by various ligands (in particular functionalized calixarenes) carrying acetamide-phosphine oxide groups (CMPO calixarenes) has been studied. These calixarenes allow the selective extraction of light lanthanides. A size effect of the cations has been evidenced. The substituents present on the lower and upper edges of the calixarene influence the extraction and its selectiveness. Studies of experimental conditions improvement have been carried out. It is shown that the de-extraction of trivalent cations extracted by CMPO calixarenes is possible using a very low concentration nitric acid solution. This requires the use of a chlorinated or alcoholic diluent. Transport experiments using this re-extraction phase slightly acidified have shown identical separation properties to those detected in liquid-liquid extraction. Nuclear magnetic resonance (NMR) is a spectroscopic method used to identify some structural parameters in solution. The NMR nuclei relaxation theory allows to link different physical data to the relaxation time of the nuclei of a molecule. The influence of the presence of paramagnetic lanthanide and actinide cations on different nuclei of the CMPO calixarene molecule has been studied. The determination of their respective relaxation time can lead to the average distances between the cation and these nuclei. This work has led to the determination of the correlation times and to a first evaluation of the average position of the cations. (J.S.)

  12. Transfer hydrogenation reactions catalyzed by chiral half-sandwich Ruthenium complexes derived from Proline

    Indian Academy of Sciences (India)

    ARUN KUMAR PANDIA KUMAR; ASHOKA G SAMUELSON

    2016-09-01

    Chiral ruthenium half-sandwich complexes were prepared using a chelating diamine made from proline with a phenyl, ethyl, or benzyl group, instead of hydrogen on one of the coordinating arms. Three of these complexes were obtained as single diastereoisomers and their configuration identified by X-ray crystallography. The complexes are recyclable catalysts for the reduction of ketones to chiral alcohols in water. A ruthenium hydride species is identified as the active species by NMR spectroscopy and isotopic labelling experiments.Maximum enantio-selectivity was attained when a phenyl group was directly attached to the primary amine on the diamine ligand derived from proline.

  13. Synthesis of racemic and chiral BEDT-TTF derivatives possessing hydroxy groups and their achiral and chiral charge transfer complexes

    Directory of Open Access Journals (Sweden)

    Sara J. Krivickas

    2015-09-01

    , θ21 and two kinds of α’-types, and their electrical conductivities of charge transfer complexes based upon the racemic and enantiopure (S,S-2, and (R,R-2 donors originates not only from the chirality, but also the introduced intermolecular hydrogen bonds involving the hydroxymethyl groups, perchlorate anion, and the included solvent H2O.

  14. Core–shell Ag@SiO2 nanoparticles of different silica shell thicknesses: Preparation and their effects on photoluminescence of lanthanide complexes

    International Nuclear Information System (INIS)

    Highlights: • Ag@SiO2 nanoparticles of different silica shell thicknesses were prepared via the Stöber process. • Sm and Dy complexes with benzoate, 1,10-phenanthroline and 2,2′-bipyridine were synthesized. • The complex-doped Ag@SiO2 composites show stronger luminescent intensities than pure complexes. • The luminescent intensities of the composites strongly depend on the SiO2 shell thickness. - Abstract: Three kinds of almost spherical core–shell Ag@SiO2 nanoparticles of different silica shell thicknesses (10, 25 and 80 nm) were prepared via the Stöber process. The Ag core nanoparticles were prepared by reducing silver nitrate with sodium citrate. The size, morphology and structure of core–shell Ag@SiO2 nanoparticles were characterized by transmission electron microscopy. Subsequently, eight kinds of lanthanide complexes with benzoate, 1,10-phenanthroline and 2,2′-bipyridine were synthesized. The composition of the lanthanide complexes was characterized by elemental analysis, IR and UV spectra. Finally, lanthanide complexes were attached to the surface of Ag@SiO2 nanoparticles to form lanthanide-complex-doped Ag@SiO2 nanocomposites. The results show that the complex-doped Ag@SiO2 nanocomposites display much stronger luminescence intensities than the lanthanide complexes. Furthermore, the luminescence intensities of the lanthanide-complex-doped Ag@SiO2 nanocomposites with SiO2 shell thickness of 25 nm are stronger than those of the nanocomposites with SiO2 shell thickness of 10 and 80 nm

  15. Core–shell Ag@SiO{sub 2} nanoparticles of different silica shell thicknesses: Preparation and their effects on photoluminescence of lanthanide complexes

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jie; Li, Yuan; Chen, Yingnan; Wang, Ailing; Yue, Bin; Qu, Yanrong; Zhao, Yongliang; Chu, Haibin, E-mail: chuhb@imu.edu.cn

    2015-11-15

    Highlights: • Ag@SiO{sub 2} nanoparticles of different silica shell thicknesses were prepared via the Stöber process. • Sm and Dy complexes with benzoate, 1,10-phenanthroline and 2,2′-bipyridine were synthesized. • The complex-doped Ag@SiO{sub 2} composites show stronger luminescent intensities than pure complexes. • The luminescent intensities of the composites strongly depend on the SiO{sub 2} shell thickness. - Abstract: Three kinds of almost spherical core–shell Ag@SiO{sub 2} nanoparticles of different silica shell thicknesses (10, 25 and 80 nm) were prepared via the Stöber process. The Ag core nanoparticles were prepared by reducing silver nitrate with sodium citrate. The size, morphology and structure of core–shell Ag@SiO{sub 2} nanoparticles were characterized by transmission electron microscopy. Subsequently, eight kinds of lanthanide complexes with benzoate, 1,10-phenanthroline and 2,2′-bipyridine were synthesized. The composition of the lanthanide complexes was characterized by elemental analysis, IR and UV spectra. Finally, lanthanide complexes were attached to the surface of Ag@SiO{sub 2} nanoparticles to form lanthanide-complex-doped Ag@SiO{sub 2} nanocomposites. The results show that the complex-doped Ag@SiO{sub 2} nanocomposites display much stronger luminescence intensities than the lanthanide complexes. Furthermore, the luminescence intensities of the lanthanide-complex-doped Ag@SiO{sub 2} nanocomposites with SiO{sub 2} shell thickness of 25 nm are stronger than those of the nanocomposites with SiO{sub 2} shell thickness of 10 and 80 nm.

  16. Peptide-lanthanide cation equilibria in aqueous phase. I. Bound shifts for L-carnosine-praseodymium complexes

    Science.gov (United States)

    Mossoyan, J.; Asso, M.; Benlian, D.

    L-Carnosine complexes of Pr 3+ were characterized in aqueous solution by 1H NMR and potentiometric titration. A rigorous treatment of chemical shifts and pH variation data with lanthanide concentration is presented. Two different forms of the peptide ligand, forming simultaneously two complexes, were taken into account. At low pH values the cation is only coordinated at the carboxylate site of the ligand in a weak complex ( β2 = 6) whereas in neutral solution a stronger complex ( β1 = 37) is present as a consequence of the deprotonation of the imidazole ring. The computation of induced bound shifts † 2 and Δ1 for resonating nuclei of the peptide in both forms yields consistent figures. These provide the experimental basis for a conformational model which is usually not obtainable for labile complexes with low stability constants.

  17. Effect of γ-radiation on the IR spectra of lanthanide 8-hydroxyquinoline complexes

    International Nuclear Information System (INIS)

    IR absorption spectra of eight lanthanide elements chelated with 8-hydroxyquinoline were measured before and after gamma irradiation with different doses (25-850 MR). It was found that the rate of decrease K of M-O and C-O absorption bands depend on the chelated cation. A mechanism based on the target theory is proposed. (author)

  18. Complexes of Y, La, and lanthanides with m-aminobenzoic acid

    International Nuclear Information System (INIS)

    m-Aminobenzoates of Y, La and lanthanides prepared in the reaction of the hydroxides of metal with m-aminobenzoic acid in solution have the general formula Ln(m-C6H4NH2COO)3.nH2O where n = 4 for Ho, Tm, n = 5 for Y, Sm, Dy, Er, Lu, and n = 6 for La, Nd, Eu, Gd, Tb, Yb. The water molecules in the hydrated compounds are in the outer coordination sphere. On heating in air at 350-410K dehydration occurs and anhydrous m-aminobenzoates Ln(m-C6H4NH2COO)3 are formed. On the basis of the IR spectra it was found that the metal in hydrated m-aminobenzoate of lanthanides is simultaneously coordinated through amino- and carboxyl groups whereas in anhydrous m-aminobenzoates of lanthanides only trough the bidentate carboxyl group. From X-ray analysis it was stated that the hydrated m-aminobenzoates of lanthanides are isostructural in the whole range Y, La-Lu. (Author)

  19. Structure and potential applications of amido lanthanide complexes chelated by bifunctional b-diketiminate ligand

    Czech Academy of Sciences Publication Activity Database

    Olejník, R.; Padělková, Z.; Fridrichová, A.; Horáček, Michal; Merna, J.; Růžička, A.

    2014-01-01

    Roč. 759, JUN 2014 (2014), s. 1-10. ISSN 0022-328X R&D Projects: GA ČR GAP106/10/0924 Institutional support: RVO:61388955 Keywords : Bifunctional b-diketiminates * lanthanides * hydroamination Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.173, year: 2014

  20. Dynamic localization of electronic excitation in photosynthetic complexes revealed with chiral two-dimensional spectroscopy

    Science.gov (United States)

    Fidler, Andrew F.; Singh, Ved P.; Long, Phillip D.; Dahlberg, Peter D.; Engel, Gregory S.

    2014-02-01

    Time-resolved ultrafast optical probes of chiral dynamics provide a new window allowing us to explore how interactions with such structured environments drive electronic dynamics. Incorporating optical activity into time-resolved spectroscopies has proven challenging because of the small signal and large achiral background. Here we demonstrate that two-dimensional electronic spectroscopy can be adapted to detect chiral signals and that these signals reveal how excitations delocalize and contract following excitation. We dynamically probe the evolution of chiral electronic structure in the light-harvesting complex 2 of purple bacteria following photoexcitation by creating a chiral two-dimensional mapping. The dynamics of the chiral two-dimensional signal directly reports on changes in the degree of delocalization of the excitonic states following photoexcitation. The mechanism of energy transfer in this system may enhance transfer probability because of the coherent coupling among chromophores while suppressing fluorescence that arises from populating delocalized states. This generally applicable spectroscopy will provide an incisive tool to probe ultrafast transient molecular fluctuations that are obscured in non-chiral experiments.

  1. Microwave assisted synthesis, spectroscopic, electrochemical and DNA cleavage studies of lanthanide(III) complexes with coumarin based imines

    Science.gov (United States)

    Kapoor, Puja; Fahmi, Nighat; Singh, R. V.

    2011-12-01

    The present work stems from our interest in the synthesis, characterization and biological evaluation of lanthanide(III) complexes of a class of coumarin based imines which have been prepared by the interaction of hydrated lanthanide(III) chloride with the sodium salts of 3-acetylcoumarin thiosemicarbazone (ACTSZH) and 3-acetylcoumarin semicarbazone (ACSZH) in 1:3 molar ratio using thermal as well as microwave method. Characterization of the ligands as well as the metal complexes have been carried out by elemental analysis, melting point determinations, molecular weight determinations, magnetic moment, molar conductance, IR, 1H NMR, 13C NMR, electronic, EPR, X-ray powder diffraction and mass spectral studies. Spectral studies confirm ligands to be monofunctional bidentate and octahedral environment around metal ions. The redox behavior of one of the synthesized metal complex was investigated by cyclic voltammetry. Further, free ligands and their metal complexes have been screened for their antimicrobial as well as DNA cleavage activity. The results of these findings have been presented and discussed.

  2. The self-aggregation of chiral threonine-linked porphyrins and their zinc(Ⅱ) complexes

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The self-aggregation of chiral threonine-linked porphyrins and their zinc(Ⅱ) complexes in water-alcohol system and water-alcohol-NaCl system has been studied by circular dichroism (CD),UV-Vis absorption spectra and fluorescence spectra methods.The experiment results indicate that chiral threonine-linked porphyrins and their zinc(Ⅱ) complexes have two different kinds of aggregates in water-alcohol system and water-alcohol-NaCl system.And the porphyrins may form highly organized and orientated aggregates in water-alcohol-NaCl system.The aggregates in water-alcohol-NaCl system may have helical structures.

  3. Non-linear sigma models via the chiral de Rham complex

    CERN Document Server

    Ekstrand, Joel; Kallen, Johan; Zabzine, Maxim

    2009-01-01

    We propose a physical interpretation of the chiral de Rham complex as a formal Hamiltonian quantization of the supersymmetric non-linear sigma model. We show that the chiral de Rham complex on a Calabi-Yau manifold carries all information about the classical dynamics of the sigma model. Physically, this provides an operator realization of the non-linear sigma model. Mathematically, the idea suggests the use of Hamiltonian flow equations within the vertex algebra formalism with the possibility to incorporate both left and right moving sectors within one mathematical framework.

  4. A novel CMPO-functionalized task specific ionic liquid: synthesis, extraction and spectroscopic investigations of actinide and lanthanide complexes.

    Science.gov (United States)

    Mohapatra, Prasanta K; Kandwal, Pankaj; Iqbal, Mudassir; Huskens, Jurriaan; Murali, Mallekav S; Verboom, Willem

    2013-04-01

    A novel CMPO (carbamoylmethylphosphine oxide) based task specific ionic liquid (TSIL) with an NTf(2)(-) counter anion was synthesized and evaluated for actinide/lanthanide extraction from acidic feed solutions using several room temperature ionic liquids (RTILs). The extraction data were compared with those obtained with CMPO in the same set of RTILs and also in the molecular diluent, n-dodecane. The extracted species were analyzed by the conventional slope analysis method and the extraction followed an ion-exchange mechanism. The nature of bonding in the extracted complexes was investigated by various spectroscopic techniques such as FT-IR and UV-visible spectroscopy. PMID:23403959

  5. Chiral Recognition in Neutral and Ionic Molecular Complexes

    Science.gov (United States)

    Sen, Ananya; Bouchet, Aude; Lepere, Valeria; Le Barbu-Debus, Katia; Zehnacker-Rentien, Anne

    2013-06-01

    The behaviour of chiral molecules in the gas phase have been studied. The two pseudoenantiomers of Quinine, have been put intact in the gas phase using laser ablation and characterized using different spectroscopic techniques such as REMPI, LIF, IR-UV double resonance. VCD measurements have been performed in solution. From this comparative study one can conclude that the pseudoenantiomers behave differently both in gas phase and in solution. Ananya Sen, Aude Bouchet, Valeria Lepère, Katia Le Barbu-Debus, D. Scuderi, F. Piuzzi, and A. Zehnacker-Rentien, J. Phys. Chem. A, 2012, 116 (32), pp 8334-8344

  6. Lanthanide Complexes with Cucurbit[n]urils (n=5, 6, 7) and Perrhenate Ligands: New Examples of Encapsulation of Perrhenate Anions

    International Nuclear Information System (INIS)

    The reaction of lanthanide nitrates with cucurbit[n]urils (CBn, n = 5, 6, 7) under hydrothermal conditions in the presence of perrhenic acid and, for some of them, other reactants such as KNO3 yielded 14 new complexes which were crystallographically characterized and present some original features. Four of the five complexes with CB5 are capsules closed by a lanthanide ion (Ce, Sm, Gd) on one side and potassium on the other and have an encapsulated bridging nitrate ion, but the fifth is a mono-dimensional polymer with both bidentate portals of CB5 complexed to ytterbium. All eight CB6 complexes (Ce, Pr, Sm, Gd, Yb, Lu) and the single ytterbium complex of CB7 (the first lanthanide complex of CB7 to be characterized) involve perrhenate encapsulation, in a form which is either bridging the lanthanide ions coordinated at each tridentate portal, or terminal when the CB is bidentate and the cation is further from the portal, or even non-coordinating in one case. The orientation of the cation in the cavity varies depending upon its coordination mode, as well as the nature of the shortest contacts in the cavity. Some original architectures are described, in particular a sinuous chain, ribbon like assembly in a cerium complex of CB6 and a novel samarium-CB6 sandwich complex. The ubiquitous encapsulation of ReO4- in CB6 and CB7 may open new perspectives for the investigation of anion complexation by these macrocycles. (author)

  7. Synthesis and characterisation of lanthanide nicotinates and their mixed complexes using dimethylglyoxime, salicylaldoxime and pyridine-2-aldoxime as secondary ligands

    International Nuclear Information System (INIS)

    Simple complexes of the type Ln(L)3 and mixed complexes of the type Ln(L)3(L').nH2O where Ln = Y(III), La(III), Pr(III), Nd(III), Sm(III), Gd(III) and Dy(III), L = nicotinic acid, L' = dimethylglyoxime, salicylaldoxime, pyridine-2-aldoxime and n = 2 or 3 have been prepared and characterised by a study of elemental analysis, electronic spectra, infrared spectra, thermoanalytical and conductivity measurements. The nmr spectra of La(II), Pr(III) and Dy(III) nicotinates and their mixed complexes have been recorded to elucidate the changes in chemical shift observed by these ions. A coordination number six and eight is suggested for the several lanthanide ions in simple and mixed complexes respectively. (author). 17 refs., 5 tabs

  8. Comparison of Theory and Observations of the Chirality of Filaments within a Dispersing Activity Complex

    Science.gov (United States)

    Mackay, D. H.; Gaizauskas, V.; van Ballegooijen, A. A.

    2000-12-01

    We investigate the origin of the hemispheric pattern of filaments and filament channels by comparing theoretical predictions with observations of the chirality of filament channels within a dispersing activity complex. Our aim is to determine how the chirality of each specific channel arises so that general principles underlying the hemispheric pattern can be recognized. We simulate the field lines representing the filaments in the activity complex by applying a model of global flux transport to an initial magnetic configuration. The model combines the surface effects of differential rotation, meridional flows, and supergranular diffusion along with a magnetofrictional relaxation method in the overlying corona. The simulations are run with and without injecting axial magnetic fields at polarity inversion lines in the dispersing activity complex for four successive solar rotations. When the initial magnetic configuration, based on synoptic magnetic maps, is set to a potential field at the beginning of each rotation, the simulations poorly predict the chirality of the filament channels and filaments. The cases that predict the correct chirality correspond to an initial polarity inversion line, which is north-south the wrong chirality arises when the initial polarity inversion lines lie east-west. Results improve when field-line connectivities at low latitudes are retained and allowed to propagate to higher latitudes without resetting the field to a potential configuration between each rotation. When axial flux emergence exceeding 1×1019 Mx day-1 is included at the location of each filament, an excellent agreement is obtained between the theory and observations. In additon to predicting the correct chirality in all cases, axial flux emergence allows more readily the production of inverse-polarity dipped field lines needed to support filamentary mass. An origin for the hemispheric pattern as a result of the combined effects of flux transport, axial flux emergence, and

  9. Asymmetric Michael Reaction of Malononitrile Catalyzed by Chiral Ru(Ⅱ) Complex and Achiral Base

    Institute of Scientific and Technical Information of China (English)

    MA Ya-Ping; XING Zhi-Kui; ZHU Jin; CUI Xin; CUN Lin-Feng; DENG Jin-Gen

    2003-01-01

    @@ Michael addition reactions represent one of the most important carbon-carbon bond forming reactions in modern synthetic organic chemistry. [1 ~3] We achieved catalytic enantioselective Michael addition reactions of malononitrile with chiral vicinal diamine-Ru(Ⅱ) complex in the presence of achiral base. High yields and moderate ee were observed.

  10. Study of the selectivity of poly-nitrogenous extracting molecules in the complexation of actinides (III) and lanthanides (III) in solution in anhydrous pyridine

    International Nuclear Information System (INIS)

    The aim of this work is to better understand the factors which contribute to the separation of lanthanides(III) and actinides(III). Polydentate nitrogenous molecules present an interesting selectivity. A thermodynamic study of the complexation in pyridine of lanthanide and uranium by the bipyridine ligand (bipy) has been carried out. The formation constants and the thermodynamic values of the different complexes have been determined. It has been shown that the bipy complexes formation is controlled by the enthalpy and unfavored by the entropy. The conductometry has revealed too a significant difference in the uranium and lanthanides complexation by the bipyridine ligand. The use of the phenanthroline ligand induces a better complexation of the metallic ions but the selectivity is not improved. On the other hand, the decrease of the basicity and the increase of the ligand denticity (for instance in the case of the use of ter-pyridine) favour the selectivity without improving the complexation. The selectivity difference for the complexation of actinides(III) and lanthanides(III) by the different studied ligands (independent systems) has been confirmed by experiments of inter-metals competition. (O.M.)

  11. Chiral linker-bridged bis-N-heterocyclic carbenes: design, synthesis, palladium complexes, and catalytic properties.

    Science.gov (United States)

    Zhang, Dao; He, Yu; Tang, Junkai

    2016-08-01

    A series of chiral bis(benzimidazolium) salts 10-19 with (1R,2R)-cyclohexene, (1R,2R)-diphenylethylene and (aR)-binaphthylene linkers have been designed and synthesized in 30-94% yield. Ten chiral bis(NHC) palladium complexes 20-28 have been synthesized and characterized by NMR, HRMS, elemental analysis and further confirmed by X-ray single crystal analysis. These bis(NHC)-Pd complexes showed obviously different catalytic properties in the asymmetric Suzuki-Miyaura coupling reactions. The (1R,2R)-cyclohexene-bridged bis(NHC)-Pd complex, (R,R)-23, achieved the highest yield of 90%, while complex (aR)-28, with a binaphthylene linker, showed the best enantioselectivity of 60 ee%. The structural analysis of these complexes suggested that such difference of catalytic performance has a close relationship with their coordination surroundings around metal centres. PMID:27230553

  12. Lanthanide single molecule magnets

    CERN Document Server

    Tang, Jinkui

    2015-01-01

    This book begins by providing basic information on single-molecule magnets (SMMs), covering the magnetism of lanthanide, the characterization and relaxation dynamics of SMMs, and advanced means of studying lanthanide SMMs. It then systematically introduces lanthanide SMMs ranging from mononuclear and dinuclear to polynuclear complexes, classifying them and highlighting those SMMs with high barrier and blocking temperatures – an approach that provides some very valuable indicators for the structural features needed to optimize the contribution of an Ising type spin to a molecular magnet. The final chapter presents some of the newest developments in the lanthanide SMM field, such as the design of multifunctional and stimuli-responsive magnetic materials as well as the anchoring and organization of the SMMs on surfaces. In addition, the crystal structure and magnetic data are clearly presented with a wealth of illustrations in each chapter, helping newcomers and experts alike to better grasp ongoing trends and...

  13. Lanthanide single molecule magnets

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Jinkui; Zhang, Peng [Chinese Academy of Sciences, Changchun (China). Changchun Inst. of Applied Chemistry

    2015-10-01

    This book begins by providing basic information on single-molecule magnets (SMMs), covering the magnetism of lanthanide, the characterization and relaxation dynamics of SMMs and advanced means of studying lanthanide SMMs. It then systematically introduces lanthanide SMMs ranging from mononuclear and dinuclear to polynuclear complexes, classifying them and highlighting those SMMs with high barrier and blocking temperatures - an approach that provides some very valuable indicators for the structural features needed to optimize the contribution of an Ising type spin to a molecular magnet. The final chapter presents some of the newest developments in the lanthanide SMM field, such as the design of multifunctional and stimuli-responsive magnetic materials as well as the anchoring and organization of the SMMs on surfaces. In addition, the crystal structure and magnetic data are clearly presented with a wealth of illustrations in each chapter, helping newcomers and experts alike to better grasp ongoing trends and explore new directions.

  14. Multicolor emission from terpyridine-lanthanide ion complexes encapsulated in nanocomposite silica/poly(ethylene glycol) sol-gel matrices

    Energy Technology Data Exchange (ETDEWEB)

    Bekiari, Vlasoula; Lianos, Panagiotis

    2003-01-15

    Complex formation between Terpyridine and trivalent metal cations, namely In{sup 3+}, Eu{sup 3+} and Tb{sup 3+} have been studied in different environments. Blue, green and red emission can be obtained from Terpyridine-Europium ion complexes, stabilized by poly(ethylene glycol) (PEG) oligomers in nanocomposite organic/inorganic matrices, by single Near-UV excitation in the ligand absorption band. Nanocomposite matrices have been synthesized by the sol-gel method. Single color, efficient photoluminescence can be also obtained by varying matrix composition. This behavior is the result of combination of three different physicochemical mechanisms: complex formation between Terpyridine and metal cations in coordination with PEG; ligand cis-trans or trans-trans transformations; and energy transfer from excited ligand to lanthanide ions.

  15. Secret Lanthanides

    OpenAIRE

    Sturza, CM

    2014-01-01

    Abstract Lanthanides are a group of 15 chemical elements which, together with their salts, have come to be used in the last decade as homoeopathic remedies. The effective introduction of lanthanides and their salts into the clinical use, as homoeopathic remedies was based on the idea of Jan Scholten, MD to relate their physicochemical properties shown in the periodic table of elements to their homoeopathic potential. The lanthanides and their salts were prepared as homoeopathic remedies by Ph...

  16. Chiral benzamidinate ligands in rare-earth-metal coordination chemistry.

    Science.gov (United States)

    Benndorf, Paul; Kratsch, Jochen; Hartenstein, Larissa; Preuss, Corinna M; Roesky, Peter W

    2012-11-01

    The treatment of the recently reported potassium salt (S)-N,N'-bis-(1-phenylethyl)benzamidinate ((S)-KPEBA) and its racemic isomer (rac-KPEBA) with anhydrous lanthanide trichlorides (Ln = Sm, Er, Yb, Lu) afforded mostly chiral complexes. The tris(amidinate) complex [{(S)-PEBA}(3)Sm], bis(amidinate) complexes [{Ln(PEBA)(2)(μ-Cl)}(2)] (Ln = Sm, Er, Yb, Lu), and mono(amidinate) compounds [Ln(PEBA)(Cl)(2)(thf)(n)] (Ln = Sm, Yb, Lu) were isolated and structurally characterized. As a result of steric effects, the homoleptic 3:1 complexes of the smaller lanthanide atoms Yb and Lu were not accessible. Furthermore, chiral bis(amidinate)-amido complexes [{(S)-PEBA}(2)Ln{N(SiMe(3))(2)}] (Ln = Y, Lu) were synthesized by an amine-elimination reaction and salt metathesis. All of these chiral bis- and tris(amidinate) complexes had additional axial chirality and they all crystallized as diastereomerically pure compounds. By using rac-PEBA as a ligand, an achiral meso arrangement of the ligands was observed. The catalytic activities and enantioselectivities of [{(S)-PEBA}(2)Ln{N(SiMe(3))(2)}] (Ln = Y, Lu) were investigated in hydroamination/cyclization reactions. A clear dependence of the rate of reaction and enantioselectivity on the ionic radius was observed, which showed higher reaction rates but poorer enantioselectivities for the yttrium compound. PMID:23015310

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

    Institute of Scientific and Technical Information of China (English)

    K. Mohanan; R. Aswathy; L.P. Nitha; Niecy Elsa Mathews; B. Sindhu Kumari

    2014-01-01

    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.

  18. Chiral copper(II) complex based on natural product rosin derivative as promising antitumour agent.

    Science.gov (United States)

    Fei, Bao-Li; Huang, Zhi-Xiang; Xu, Wu-Shuang; Li, Dong-Dong; Lu, Yang; Gao, Wei-Lin; Zhao, Yue; Zhang, Yu; Liu, Qing-Bo

    2016-07-01

    To evaluate the biological preference of chiral drug candidates for molecular target DNA, the synthesis and characterization of a chiral copper(II) complex (2) of a chiral ligand N,N'-(pyridin-2-ylmethylene) dehydroabietylamine (1) was carried out. The interactions of 1 and 2 with salmon sperm DNA were investigated by viscosity measurements, UV, fluorescence and circular dichroism (CD) spectroscopic techniques. Absorption spectral, emission spectral and viscosity analysis reveal that 1 and 2 interacted with DNA through intercalation and 2 exhibited a higher DNA binding ability. In the absence/presence of ascorbic acid, 1 and 2 cleaved supercoiled pBR322 DNA by single-strand and 2 displayed stronger DNA cleavage ability. In addition, in vitro cytotoxicity of 1 and 2 against HeLa, SiHa, HepG-2 and A431 cancer cell lines study show that they exhibited effective cytotoxicity against the tested cell lines, notably, 2 showed a superior cytotoxicity than the widely used drug cisplatin under identical conditions, indicating it has the potential to act as effective anticancer drug. Flow cytometry analysis indicates 2 produced death of HeLa cancer cells through an apoptotic pathway. Cell cycle analysis demonstrates that 2 mainly arrested HeLa cells at the S phase. The study represents the first step towards understanding the mode of the promising chiral rosin-derivative based copper complexes as chemotherapeutics. PMID:27088508

  19. Effect of molecular structure of tartrates on chiral recognition of tartrate-boric acid complex chiral selectors in chiral microemulsion electrokinetic chromatography.

    Science.gov (United States)

    Hu, Shao-Qiang; Chen, Yong-Lei; Zhu, Hua-Dong; Shi, Hai-Jun; Yan, Na; Chen, Xing-Guo

    2010-08-20

    Eight l-tartrates and a d-tartrate with different alcohol moieties were used as chiral oils to prepare chiral microemulsions, which were utilized in conjunction with borate buffer to separate the enantiomers of beta-blockers or structurally related compounds by the chiral microemulsion electrokinetic chromatography (MEEKC) method. Among them, six were found to have a relatively good chiral separation performance and their chiral recognition effect in terms of both enantioselectivity and resolution increases linearly with the number of carbon atoms in the alkyl group of alcohol moiety. The tartrates containing alkyl groups of different structures but the same number of carbon atoms, i.e. one of straight chain and one of branched chain, provide similar enantioseparations. The trend was elucidated according to the changes in the difference of the steric matching between the molecules of two enantiomers and chiral selector. Furthermore, it was demonstrated for the first time that a water insoluble solid compound, di-i-butyl l-tartrate (mp. 73.5 degrees C), can be used as an oil to prepare a stable microemulsion to be used in the chiral MEEKC successfully. And a critical effect of the microemulsion for chiral separation, which has never been reported before, was found in this experiment, namely providing a hydrophobic environment to strengthen the interactions between the chiral selector and enantiomers. PMID:20638068

  20. Using remote substituents to control solution structure and anion binding in lanthanide complexes

    DEFF Research Database (Denmark)

    Tropiano, Manuel; Blackburn, Octavia A.; Tilney, James A.;

    2013-01-01

    of the molecule, at a substantial distance from the binding pocket. Herein, we explore these remote substituent effects and explain the observed behaviour through discussion of the way in which remote substituents can influence and control the global structure of a molecule through their demands upon...... conformational space. Peripheral modifications to a binuclear lanthanide motif derived from α,α'-bis(DO3 Ayl)-m-xylene are shown to result in dramatic changes to the binding constant for isophthalate. In this system, the parent compound displays considerable conformational flexibility, yet can be assumed to bind...

  1. Syntheses, spectroscopic study and X-ray crystallography of some new phosphoramidates and lanthanide(III) complexes of N-(4-nitrobenzoyl)-N',N''-bis(morpholino)phosphoric triamide

    Czech Academy of Sciences Publication Activity Database

    Gholivand, K.; Mostaanzadeh, H.; Kovaľ, Tomáš; Dušek, Michal; Erben, M.F.; Stoeckli-Evans, H.; Della Védova, C.O.

    2010-01-01

    Roč. 66, Part 4 (2010), s. 441-450. ISSN 0108-7681 Grant ostatní: AVČR(CZ) Praemium Academiae Institutional research plan: CEZ:AV0Z10100521 Keywords : phosphoramidates * lanthanide(III) complexes * NMR * IR spectroscopy * x-ray crystallography Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.829, year: 2010

  2. Homodinuclear lanthanide {Ln2} (Ln = Gd, Tb, Dy, Eu) complexes prepared from an o-vanillin based ligand: luminescence and single-molecule magnetism behavior.

    Science.gov (United States)

    Bag, Prasenjit; Rastogi, Chandresh Kumar; Biswas, Sourav; Sivakumar, Sri; Mereacre, Valeriu; Chandrasekhar, Vadapalli

    2015-03-01

    Four dinuclear lanthanide complexes [Gd2 (H2L)2 (µ-piv)2 (piv)2]·2CHCl3 (1), [Tb2 (H2L)2 (µ-piv)2 (piv)2]·2CHCl3 (2), [Dy2 (H2L)2 (µ-piv)2 (piv)2]·2CHCl3 (3) and [Eu2 (H2L)2 (µ-piv)2 (piv)2]·2CHCl3 (4) were synthesized by the reaction of appropriate Ln(III) chloride salts and a multidentate ligand, 2,2'-(2-hydroxy-3-methoxy-5-methylbenzylazanediyl)diethanol (H3L) in the presence of pivalic acid. 1-4 are neutral and are held by two monoanionic, [H2L](-) ligands. The two lanthanide ions are doubly bridged to each other via two phenolate oxygen atoms. Both the lanthanide ions are nine coordinated and possess a distorted capped square antiprism geometry. Photophysical studies reveal that Tb(3+) (2) and Dy(3+) (3) complexes display strong ligand-sensitized lanthanide-characteristic emission. The Tb(3+) complex (2) shows a very high overall quantum yield of 76.2% with a lifetime of 1.752 ms. Magnetic studies reveal single-molecule magnet behavior for 3 which shows in its ac susceptibility studies a two-step slow relaxation yielding two effective relaxation energy barriers of ΔE = 8.96 K and 35.51 K. PMID:25641498

  3. Microwave assisted synthesis, spectroscopic, thermal, and antifungal studies of some lanthanide(Ⅲ) complexes with a heterocyclic bishydrazone

    Institute of Scientific and Technical Information of China (English)

    K. Mohanan; B. Sindhu Kumari; G. Rijulal

    2008-01-01

    A bishydrazone formed by the condensation of isatinmonohydrazone and salicylaldehyde reacted with lanthanide(Ⅲ) chloride to form complexes of the type [Ln(HISA)2Cl3], where, Ln=La(Ⅲ), ce(Ⅲ), Pr(Ⅲ), Nd(Ⅲ), Sin(Ⅲ), Eu(Ⅲ), or Gd(Ⅲ) and HISA=[(2-hydroxybenzaldehyde)-3-isatin]bishydrazone. Both reactions were carried out under microwave conditions. The ligand and the metal complexes were characterized on the basis of elemental analysis, molar conductance, magnetic susceptibility measurements, UV visible, infrared, far infrared, and proton NMR spectral data. The ligand acted as neutral tridentate, coordinating through the carbonyl oxygen, azomethine nitrogen, and phenolic oxygen without deprotonation. The ligand and lanthanum(Ⅲ) complex were subjected to X-ray diffraction studies. The X-ray diffraction pattern of ligand exhibited its crystalline nature and that of the lanthanum(Ⅲ) complex indicated its amorphous character. The thermal decomposition behaviour of the complex, [La(HISA)2Cl3], was examined in the temperature range of 40-800 ℃ using TG, DTG, and DTA. The ligand and the metal complexes were screened for their antifungal activities.

  4. Chiral photochemistry

    CERN Document Server

    Inoue, Yoshihisa

    2004-01-01

    Direct Asymmetric Photochemistry with Circularly Polarized Light, H. RauCoherent Laser Control of the Handedness of Chiral Molecules, P. Brumer and M. ShapiroMagnetochiral Anisotropy in Asymmetric Photochemistry, G.L.J.A.RikkenEnantiodifferentiating Photosensitized Reactions, Y. InoueDiastereodifferentiating Photoreactions, N. Hoffmann and J.-P. PeteChirality in Photochromism, Y. Yokoyama and M. SaitoChiral Photochemistry with Transition Metal Complexes, S. Sakaki and T. HamadaTemplate-Induced Enantioselective Photochemical Reactions in S

  5. Ruthenium and rhodium complexes with chiral P-donor ligands as catalysts of enantioselective hydrogenation of ketoesters

    International Nuclear Information System (INIS)

    The use of ruthenium(II) and rhodium(III) complexes with chiral P-donor ligands as catalysts of asymmetric hydrogenation of α-, β- and γ-ketoesters is considered. The attention is focused on highly enantioselective processes.

  6. The chiral de Rham complex and quantum non-linear sigma models

    International Nuclear Information System (INIS)

    In [J. Ekstrand, R. Heluani, J. Kaellen, M. Zabzine, Adv. Theor. Math. Phys. 13 (2009) 1221-1254; J. Ekstrand, R. Heluani, J. Kaellen, M. Zabzine, (arXiv:1003.4388 [hep-th])], the interpretation of the chiral de Rham complex as a formal quantization of 2d non-linear sigma models in the Hamiltonian framework was suggested and used to compute symmetry algebras for quantum models with non-flat target spaces. Here we review the construction.

  7. The chiral de Rham complex and quantum non-linear sigma models

    Energy Technology Data Exchange (ETDEWEB)

    Kaellen, J. [Department of Physics and Astronomy, Division of Theoretical Physics, Uppsala University, Box 516, SE-751 20 Uppsala (Sweden)

    2011-07-15

    In [J. Ekstrand, R. Heluani, J. Kaellen, M. Zabzine, Adv. Theor. Math. Phys. 13 (2009) 1221-1254; J. Ekstrand, R. Heluani, J. Kaellen, M. Zabzine, (arXiv:1003.4388 [hep-th])], the interpretation of the chiral de Rham complex as a formal quantization of 2d non-linear sigma models in the Hamiltonian framework was suggested and used to compute symmetry algebras for quantum models with non-flat target spaces. Here we review the construction.

  8. Structural study of the uranyl and rare earth complexation functionalized by the CMPO; Etude structurale de la complexation de l'uranyle et des ions lanthanides par des calixarenes fonctionnalises par le CMPO

    Energy Technology Data Exchange (ETDEWEB)

    Cherfa, S

    1998-12-10

    In view of reducing the volume of nuclear waste solutions, a possible way is to extract simultaneously actinide and lanthanide ions prior to their ulterior separation.. Historically, the two extractant families used for nuclear waste reprocessing are the phosphine oxides and the CMPO (Carbamoyl Methyl Phosphine Oxide). For a better understanding of the complexes formed during extraction, we undertook structural studies of the complexes formed between uranyl and lanthanide (III) ions and the two classes of ligands cited above. These studies have been performed by X-ray diffraction on single crystals. Recently, a new type of extractants of lanthanide (III) and actinide (III) ions has been developed. When the Organic macrocycle called calixarene (an oligomeric compound resulting from the poly-condensation of phenolic units) is functionalized by a CMPO ligand, the extracting power, in terms of yield and selectivity towards lightest lanthanides, is greatly enhanced compared to the one measured for the single CMPO. Our X-ray diffraction studies allowed us to characterise, in terms of stoichiometry and monodentate or bidentate coordination mode of the CMPO functions, the complexes of calix[4]arene-CMPO (with four phenolic units) with lanthanide nitrates and uranyl. These different steps of characterisation enabled us to determine the correlation between the structures of the complexes and both selectivity and exacerbation of the extracting power measured in the liquid phase. (author)

  9. The structure determination of uranocene and the first COT lanthanide complexes

    International Nuclear Information System (INIS)

    This paper results from my introductory talk at the symposium 'Frontiers of Organo-f-Element Chemistry'. Although my active research in organo-actinide and -lanthanide chemistry ended early in my career, it led to an interest in actinide coordination chemistry that continues to this day; I am a member of the actinide research group of the Chemical Sciences Division of the Lawrence Berkeley National Laboratory. My remarks will be somewhat personal and are intended to provide a perspective on the history of this field, but I hope to connect it to what has become a new and very active area of research; this class of compounds is now associated with what are essentially quantum confined multiconfigurational molecules. (authors)

  10. Thermal decomposition of lanthanides (III) and yttrium (III) solid complexes from ethyl ene diamine tetraacetic acid

    International Nuclear Information System (INIS)

    Solid state compounds of lanthanides (III) and yttrium derived from ethyl ene diamine tetraacetic acid were prepared from respective basic carbonates, that were neutralized with EDTA stoichiometry quantities. Complexometry with EDTA, thermogravimetry (TG), differential thermal analysis (DTA) and X-ray diffraction have been used in the study of these compounds. The results of complexometry with EDTA as well as TG and DTA curves bed to the stoichiometry of these compounds the following general formula is obeyed: H[Ln(EDTA]. n H2 O. X-ray powder patterns of these compounds permitted to establish two isomorphous series. The DTA ant TG curves allowed us to study the dehydration process, the thermal stability and thermal decomposition of these compounds. (C.G.C.)

  11. Synthesis, crystal structures, luminescence and magnetic properties of lanthanide complexes containing the 1,8-bis(2-hydroxy-benzamide)-3,6-di-oxa-octane ligand

    Energy Technology Data Exchange (ETDEWEB)

    Winnie, Po-Wan Lai; Wing-Tak, Wong [Hong Kong Univ., Dept. of Chemistry, P.R. (China); Wing-Tak, Wong [PKU-PKU Joint Lab. on Rare Earth Materials, Pekin University, Beijing (China); Billy King-Fai, Li; Kwok-Wai, Cheah [Hong Kong Baptist University, Dept. of Physics, Hong Kong, P.R. (China)

    2002-05-01

    The reaction of 1,8-bis(2-hydroxy-benzamide)-3,6-di-oxa-octane (H{sub 2}L) with lanthanide nitrates in MeCN afforded new binuclear lanthanide complexes (Ln=La-Nd, Sm-Yb or Y, 1-13) in high yields, and the molecular structures of 1 and 2 were established by X-ray crystallography. A photophysical study of the ligand H{sub 2}L and of the binuclear complexes (Ln=Nd, Sm, Eu, Tb and Dy) has been performed and the quenching effect of coordinated water molecules was observed. The H{sub 2}L and Tb complex exhibit an up-conversion process under OPO excitation at 660 nm. The magnetic properties of Pr and Gd complexes are also reported. (authors)

  12. A Simple Method for Drawing Chiral Mononuclear Octahedral Metal Complexes

    Science.gov (United States)

    Mohamadou, Aminou; Haudrechy, Arnaud

    2008-01-01

    Octahedral transition-metal complexes are involved in a number of reactions and octahedral coordination geometry, frequently observed for metallic centers, includes important topographical stereochemistry. Depending on the number and nature of different ligands, octahedral coordination units with at least two different monodentate ligands give…

  13. Spontaneous Resolution and Carbonation of Chiral Benzyllithium Complexes

    DEFF Research Database (Denmark)

    Lennartson, Anders; Sundberg, Jonas; Wiklund, Tove; Hilmersson, Göran; Håkansson, Mikael

    2010-01-01

    CO2, but the bulk product was racemic. It is unclear whether the lack of selectivity originates during crystallisation or carbonation. In order to investigate this, similar complexes displaying Si or S atoms in the α-position were prepared and structurally characterized: [Li(tmsb)(tmpda)] (tmsb = 1...

  14. Synthesis, chemistry, and catalytic activity of complexes of lanthanide and actinide metals in unusual oxidation states and coordination environments. Progress report, February 1, 1981-January 31, 1982

    International Nuclear Information System (INIS)

    The objectives of this research project are: (1) to demonstrate experimentally that the lanthanide and actinide metals have a more extensive chemistry than is presently known; (2) to develop a better understanding of the special features of the f orbital elements which will allow the design of f orbital complexes possessing unique chemical and physical properties; (3) to provide a basis for seeking unusual catalytic transformations involving these elements; and (4) to synthesize and explore the chemical and physical properties of mixed metal complexes which contain both lanthanide and transition metals. During the past year progress was made in each area. Some of the specific results are: (1) the first activation of CO by an organolanthanide complex was demonstrated; (2) the first, crystallograhically characterized, molecular lanthanide hydride complexes, the bridged dimers, [(C5H4R)2LnH(THF)]2 (R=H, CH3; Ln=Lu, Er, Y), were synthesized by hydrogenolysis of the appropriate (C5H4R)2Ln(C(CH3)3)(THF) complex; (3) [(C5H5)2(THF)ErH]2 was found to catalyze the homogeneous hydrogenation of alkynes; (4) the first trimetallic organolanthanide complex was synthesized; (5) the first polyhydridic organolanthanide complex was synthesized; (6) U(III) hydride was found to catalytically activate molecular hydrogen in alkene and alkyne hydrogenation reactions

  15. Lanthanides in the frame of Molecular Magnetism

    Science.gov (United States)

    Gatteschi, D.

    2014-07-01

    Molecular magnetism is producing new types of materials which cover up to date aspects of basic science together with possible applications. This article highlights recent results from the point of view of lanthanides which are now intensively used to produce single molecule magnets, single chain and single ion magnets. After a short introduction reminding the main steps of development of molecular magnetism, the basic properties of lanthanides will be covered highlighting important features which are enhanced by the electronic structure of lanthanides, like spin frustration and chirality, anisotropy and non collinear axes in zero and one dimensional materials. A paragraph of conclusions will discuss what has been done and theperspectives to be expected.

  16. Factors Affecting the Efficiency of Excited-States Interactions of Complexes between Some Visible Light-Emitting Lanthanide Ions and Cyclophanes Containing Spirobiindanol Phosphonates

    Directory of Open Access Journals (Sweden)

    M. S. Attia

    2007-01-01

    Full Text Available The efficiency of excited-states interactions between lanthanide ions Tb3+ and Eu3+ and some new cyclophanes (I, II, and III has been studied in different media. High luminescence quantum yield values for terbium and europium complexes in DMSO and PMMA were obtained. The photophysical properties of the green and red emissive Tb3+ and Eu3+ complexes have been elucidated, respectively.

  17. Study of the selectivity of poly-nitrogenous extracting molecules in the complexation of actinides (III) and lanthanides (III) in solution in anhydrous pyridine; Etude de la selectivite de molecules extractantes polyazotees dans la complexation des actinides (III) et des lanthanides (III) en solution dans la pyridine anhydre

    Energy Technology Data Exchange (ETDEWEB)

    Riviere, Ch

    2000-10-05

    The aim of this work is to better understand the factors which contribute to the separation of lanthanides(III) and actinides(III). Polydentate nitrogenous molecules present an interesting selectivity. A thermodynamic study of the complexation in pyridine of lanthanide and uranium by the bipyridine ligand (bipy) has been carried out. The formation constants and the thermodynamic values of the different complexes have been determined. It has been shown that the bipy complexes formation is controlled by the enthalpy and unfavored by the entropy. The conductometry has revealed too a significant difference in the uranium and lanthanides complexation by the bipyridine ligand. The use of the phenanthroline ligand induces a better complexation of the metallic ions but the selectivity is not improved. On the other hand, the decrease of the basicity and the increase of the ligand denticity (for instance in the case of the use of ter-pyridine) favour the selectivity without improving the complexation. The selectivity difference for the complexation of actinides(III) and lanthanides(III) by the different studied ligands (independent systems) has been confirmed by experiments of inter-metals competition. (O.M.)

  18. Carbamoylphosphine oxide complexes of trivalent lanthanide cations: role of counterions, ligand binding mode, and protonation investigated by quantum mechanical calculations.

    Science.gov (United States)

    Boehme, C; Wipff, G

    2002-02-25

    We present a quantum mechanical study of carbamoylphosphine oxide (CMPO) complexes of MX(3) (M(3+) = La(3+), Eu(3+), Yb(3+); X(-) = Cl(-), NO(3)(-)) with a systematic comparison of monodentate vs bidentate binding modes of CMPO. The per ligand interaction energies Delta E increase from La(3+) to Yb(3+) and are higher with Cl(-) than with NO(3)(-) as counterions, as a result of steric strain in the first coordination sphere with the bidentate anions. The energy difference between monodentate (via phosphoryl oxygen) and bidentate CMPO complexes is surprisingly small, compared to Delta E or to the binding energy of one solvent molecule. Protonation of uncomplexed CMPO takes place preferably at the phosphoryl oxygen O(P), while in the Eu(NO(3))(3)CMPOH(+) complex carbonyl (O(C)) protonation is preferred and O(P) is bonded to the metal. A comparison of uranyl and lanthanide nitrate complexes of CMPO shows that the interaction energies Delta E of the former are lower. Finally, the effect of grafting CMPO arms at the wide rim of a calix[4]arene platform is described. The results are important for our understanding of cation binding and extraction by potentially bidentate CMPO, diamide, and diphosphoryl types of ligands. PMID:11849072

  19. Ligand-assisted capillary electrophoresis separations of the lanthanides

    International Nuclear Information System (INIS)

    Capillary electrophoresis is used with simple organic ligands added to the electrolyte matrix to achieve separation of the individual lanthanide cations. Results for acetate (AC-) and malonate (MA-) yield good resolution for the lighter lanthanides, but not the heavier lanthanides. In contrast, α-hydroxyisobutyrate (HIB-) gives complete resolution for all of the lanthanide cations. These results are related to the complexation chemistry between the lanthanides and the ligands across the lanthanide series. In addition, preliminary results for lanthanide separations using AC- in mixed methanol:water solvent systems are provided. The presence of methanol improves resolution but slows the separation. (author)

  20. Complexes of (EtO){sub 2}P(O)CH{sub 2}P(O)(OEt){sub 2} with lanthanide nitrates

    Energy Technology Data Exchange (ETDEWEB)

    Lees, A.M.J.; Platt, A.W.G. [Staffordshire Univ., School of Sciences, College Road, Stoke-on-Trent (United Kingdom); Kresinski, A. [Kingston Univ., School of Chemical and Pharmaceutical Sciences (United Kingdom)

    2004-12-01

    The preparation of complexes of (EtO){sub 2}P(O)CH{sub 2}P(O)(OEt){sub 2} = L, with lanthanide nitrates is described. Stable complexes with composition LnL{sub 2}(NO{sub 3}){sub 3} can be isolated for Ln = La-Eu and fully characterised. For LnGd-Lu solid compounds could not be isolated. Conductivity and {sup 31}P NMR spectroscopy indicate structural changes in solution between the lighter and heavier lanthanides and, whilst electro-spray mass spectrometry confirms a dramatic difference in behaviour with complexes of the heavier lanthanides readily decomposing via loss of EtNO{sub 3}, other experiments show that this does not occur under the conditions of complex formation. The single crystal X-ray structures for Ln = La and Sm show the nitrates and OEt groups to be in close proximity. The changes in spectroscopic properties correlate well with the difficulties in isolating the complexes of heavier metals, and are possibly due to the formation of dimeric complexes rather than loss of ethyl nitrate. (authors)

  1. Synthesis, characterization and antibacterial activity of new complexes of some lanthanide ions with 15-crown-5 and 18-crown-6

    Directory of Open Access Journals (Sweden)

    Hussein Al-Amery

    2016-05-01

    Full Text Available Complexes of some lanthanide picrates (Ln3+ = Pr3+, Nd3+ and Dy3+ with 15-crown-5 and 18-crown-6 were synthesized and characterized by elemental analysis, ICP-AES, FTIR, 1H-NMR, 13C-NMR and UV-Visible spectrophotometric methods, thermal analysis (TGA & DTG, magnetic susceptibility , molar conductance and melting points. Also an in-vitro study on pathogenic gram positive (Staphylococcus aureus and pathogenic gram negative bacteria (Escherichia coli, Salmonella and pseudomonas aeruginosa was performed and the results were compared to those of a broad spectrum antibiotic (Chloramphinicol. The complexes of 15-crown-5 have the general formula [Ln(15C52(Pic]Pic2.nH2O where (Ln3+ = Nd3+ and Dy3+, (Pic = Picrate anion and (n = 2 or 4 except for Pr3+ complex which has the formula [Pr(15C5]Pic3.H2O , the 18-crown-6 complexes have the general formula [Ln(18C6]Pic3 where (Ln3+ = Pr3+ and Nd3+ except for Dy3+ complex which has the formula [Dy(18C6(Pic]Pic2.3H2O. In 15-crown-5 complexes both Nd3+ and Dy3+ were coordinated with two 15-crown-5 ligands and one picrate anion through its phenolic oxygen and the oxygen of it’s ortho nitro group, except for Pr3+ which was coordinated with only one 15-crown-5 ligand leaving three picrate anions as counter ions. In 18-crown-6 complexes both Pr3+ and Nd3+ were coordinated with one 18-crown-6 ligand leaving all the three picrate anions as counter ions outside the coordination sphere, except for the Dy3+ complex which was coordinated with one 18-crown-6 ligand and one picrate anion.

  2. Catalytic Asymmetric Coupling of 2-Naphthols by Chiral Tridentate Oxovanadium(IV) Complexes

    Institute of Scientific and Technical Information of China (English)

    HON; Sang-Wen

    2001-01-01

    A series of chiral oxovanadium(IV) complexes derived from tridentate N-3,5-substituted-, N-3,4-benzo-and N-5,6-benzo-salicylidene-α-amino acids can serve as efficient catalysts for the enantioselective oxidative couplings of various 3-, 6-, and 7-substituted 2-naphthols under O2. The best scenario involves the use of a vanadyl complex arising from 2-hydroxy-l-naphthaldehyde and valine (or phenylalanine) in CCl4, leading to BINOLs in good yields (75-100%) and with enantioselectivities of up to 68%.……

  3. Catalytic Asymmetric Coupling of 2-Naphthols by Chiral Tridentate Oxovanadium(IV) Complexes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ A series of chiral oxovanadium(IV) complexes derived from tridentate N-3,5-substituted-, N-3,4-benzo-and N-5,6-benzo-salicylidene-α-amino acids can serve as efficient catalysts for the enantioselective oxidative couplings of various 3-, 6-, and 7-substituted 2-naphthols under O2. The best scenario involves the use of a vanadyl complex arising from 2-hydroxy-l-naphthaldehyde and valine (or phenylalanine) in CCl4, leading to BINOLs in good yields (75-100%) and with enantioselectivities of up to 68%.

  4. Quantum mechanics and molecular dynamics simulations of complexation of alkaline-earth and lanthanide cations by poly-amino-carboxylate ligands

    International Nuclear Information System (INIS)

    Molecular dynamics (MD) simulations on lanthanide(III) and alkaline-earth(II) complexes with poly-amino-carboxylates (ethylene-diamino-tetra-acetate EDTA4-, ethylene-diamino-tri-acetate-acetic acid EDTA(H)3-, tetra-aza-cyclo-dodecane-tetra-acetate DOTA4-, methylene-imidine-acetate MIDA2-) are reported. First, a consistent set of Lennard-Jones parameters for La3+, Eu3+ and Lu3+ cations has been derived from free energy calculations in aqueous solution. Observed differences in hydration free energies, coordination distances and hydration numbers are reproduced. Then, the solution structures of 1:1 complexes of alkaline-earth and/or lanthanide cations with EDTA4-, EDTA(H)3-, DOTA4- and 1:2 complexes of lanthanide cations with MIDA2- were studied by MD in water. In addition, free energy calculations were performed to study, for each ligand, the relative thermodynamic stabilities of complexes with Ca2+ vs Sr2+ and vs Ba2+ on the one hand, and with La3+ vs Eu3+ and vs Lu3+ on the other hand. Model does not take into account explicitly polarization and charge transfer. However, the results qualitatively agree with experimental complexation data (structure and selectivities). (author)

  5. Synthesis and characterization of lanthanide complexes of 1-phenyl-3-methyl-5-hydroxy-4-pyrazolyl-phenyl ketone-2'-picolinoyl hydrazone

    International Nuclear Information System (INIS)

    The ligand, 1-phenyl-3-methyl-5-hydroxy-4-pyrazolyl phenyl ketone 2'-picolinoyl hydrazone (HL) is prepared by condensation of 1-phenyl-3- methyl-4-benzoyl-5-pyrazolone with 2-picolinic acid hydrazide. Seven complexes of lanthanides with HL of the type [Ln(HL)3].2H2O (where Ln=trivalent lanthanides such as La, Ce, Nd, Sm, Gd, Dy and Er) have been synthesized and characterized by complexometric titration of lanthanoid ions, elemental analysis, molar conductance, IR, 1H NMR, electronic spectral studies and TGA analysis IR spectra and thermogram shows the presence of two water moieties outside the coordination sphere and are non-electrolytic in nature. The complexes appear to be nine-coordinated and ligand act as a tridentate ligand. (author)

  6. Configuration-averaged open shell ab initio method for crystal field levels and magnetic properties of lanthanide(III) complexes

    CERN Document Server

    Heuvel, Willem Van den; Soncini, Alessandro

    2015-01-01

    We present an ab initio methodology dedicated to the determination of the electronic structure and magnetic properties of ground and low-lying excited states, i.e., the crystal field levels, in lanthanide(III) complexes. Currently, the most popular and successful ab initio approach is the CASSCF/RASSI-SO method, consisting of the optimization of multiple complete active space self-consistent field (CASSCF) spin eigenfunctions, followed by full diagonalization of the spin--orbit coupling (SOC) Hamiltonian in the basis of the CASSCF spin states featuring spin-dependent orbitals. Based on two simple observations valid for Ln(III) complexes, namely: (i) CASSCF 4f atomic orbitals are expected to change very little when optimized for different multiconfigurational states belonging to the 4f-electronic configuration, (ii) due to strong SOC the total spin is not a good quantum number, we propose here an efficient ab initio strategy which completely avoids any multiconfigurational calculation, by optimizing a unique s...

  7. Tetranuclear lanthanide (III) complexes containing dimeric subunits: single-molecule magnet behavior for the Dy4 analogue.

    Science.gov (United States)

    Chandrasekhar, Vadapalli; Das, Sourav; Dey, Atanu; Hossain, Sakiat; Sutter, Jean-Pascal

    2013-10-21

    The reaction of the lanthanide(III) salts [Dy(III), Tb(III), and Gd (III)] with a hetero donor chelating ligand N'-(2-hydroxy-3-methoxybenzylidene)-6-(hydroxymethyl) picolinohydrazide (LH3) and pivalic acid (PivH) in the presence of tetra-n-butylammonium hydroxide (TBAH) afforded the tetranuclear Ln(III) coordination compounds, [Ln4(LH)2(LH2)2(μ2-η(1)η(1)Piv)2(η(1)Piv)4]·2CHCl3 [Ln = Dy(1), Tb(2), and Gd(3)]. The molecular structure of these complexes reveals that the tetranuclear derivatives are composed of two dinuclear subunits which are interconnected through the coordination action of the picolinoyl hydrazine ligand. Within each subunit two different types of Ln(III) ions are present. One of these is eight-coordinate in a distorted triangular dodecahedral geometry while the other is nine-coordinate in a distorted spherical capped square antiprism geometry. Alternating current (ac) susceptibility measurements of complex 1 reveal a frequency- and temperature-dependent two step out-of-phase signals under 1kOe DC field which is characteristic of a single-molecule magnet (SMM) behavior. Analysis of the magnetic data afforded the anisotropic barriers and relaxation times: Δ/kB = 62.6 K, τ0 = 8.7 × 10(-7) s; Δ/kB = 26.3 K, τ0 = 1.26 × 10(-6) s for the slow and fast relaxations respectively. PMID:24111517

  8. Synthesis and characterization of a tetranuclear copper(Ⅱ) complex with a chiral Schiff base ligand

    Institute of Scientific and Technical Information of China (English)

    Hua Xiang; Long Jiang; Huan-Yong Li; Xiao-Dan Zheng; YU Li

    2013-01-01

    The title complex l-[CuⅡ4(Hvap)2(vap)2(MeOH)2](ClO4)2 1 has been synthesized and characterized by EA,IR,TGA,solid-state CD spectra and X-ray single-crystal analyses (I-H2vap:a Schiff base ligand derived from the condensation of o-vanillin and 1-2-amino-3-phenyl-1-propanol).Complex 1 crystallizes in monoclinic system,chiral space group P21 with a=10.4257(18),b=21.695(4),c=15.721(3) (A),β =94.443(3)°,V=3545.1 (11) (A)3,Z =2,Cu4C7oH78N4O22Cl2,Mr =1652.42,Dc =1.548 g/cm3,F(0 0 0) =1704 and μ(MoKα) =1.338 mm-1.The final R =0.0682 and wR =0.1420 for 6170 observed reflections with I > 2σ(Ⅰ) and R =0.1775 and wR =0.1830 for all data.The structure of complex 1 contains a boat-shaped {Cu4O4} motif.The solid-state CD spectra confirm the chiral nature of complex 1.

  9. Synthesis, thermodynamic properties and antibacterial activities of lanthanide complexes with 3,5-dimethoxybenzoic acid and 1,10-phenanthroline

    International Nuclear Information System (INIS)

    Graphical abstract: Four novel complexes ([Ln(3,5-DmeoxBA)3(phen)]2 (Ln = Tb(1), Dy(2), Er(3), Yb(4); 3,5-DmeoxBA = 3,5-dimethoxybenzoic acid; phen = 1,10-phenanthroline))were synthesized and characterized by elemental analysis, IR and TG/DSC-FTIR technology. Heat capacities of the four complexes were measured by differential scanning calorimetry (DSC). The antibacterial action of the four complexes on bacteria and fungus such as Escherichia coli, Staphylococcus aureus and Candida albicans were studied by filter paper approach. - Highlights: • Four novel complexes ([Ln(3,5-DmeoxBA)3(phen)]2 were synthesized and characterized. • The thermal decomposition processes of the title complexes were studied using the TG/DSC–FTIR coupling techniques. • The heat capacities of the complexes were measured by (DSC). • The antibacterial action of the four complexes on Escherichia coli, Staphylococcus aureus and Candida albicans were studied. - Abstract: Four lanthanide complexes with a general formula [Ln(3,5-DmeoxBA)3(phen)]2 (Ln = Tb(1), Dy(2), Er(3), Yb(4); 3,5-DmeoxBA = 3,5-dimethoxybenzoic acid; phen = 1,10-phenanthroline) were synthesized and characterized by elemental analysis, infrared spectra (IR), and thermogravimetric, differential scanning calorimetry techniques, combined with Fourier transform infrared (TG/DSC–FTIR) technology. The thermal decomposition processes of the four complexes were investigated by TG/DSC–FTIR techniques. Heat capacities were measured by DSC. The values of the experimental heat capacities were fitted to a polynomial equation with the least-squares method. Based on the fitted polynomial, the smoothed heat capacities and thermodynamic functions (HT − H298.15K), (ST − S298.15K), and (GT − G298.15K) were calculated. The antibacterial action of the four complexes on bacteria and fungus such as Escherichia coli, Staphylococcus aureus and Candida albicans were studied by filter paper approach. The luminescent properties of the

  10. Synthesis, thermodynamic properties and antibacterial activities of lanthanide complexes with 3,5-dimethoxybenzoic acid and 1,10-phenanthroline

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jun-Ru [Testing and Analysis Center, Hebei Normal University, Shijiazhuang 050024 (China); College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024 (China); Ren, Shu-Xia [Material Science and Engineering School, Shijiazhuang Tiedao University, Shijiazhaung 050043 (China); Ren, Ning [Department of Chemistry, Handan College, Handan 056005 (China); Zhang, Jian-Jun, E-mail: jjzhang6@126.com [Testing and Analysis Center, Hebei Normal University, Shijiazhuang 050024 (China); College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024 (China); Zhang, Da-Hai [Department of Chemistry, Handan College, Handan 056005 (China); Wang, Shu-Ping [College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024 (China)

    2013-11-20

    Graphical abstract: Four novel complexes ([Ln(3,5-DmeoxBA){sub 3}(phen)]{sub 2} (Ln = Tb(1), Dy(2), Er(3), Yb(4); 3,5-DmeoxBA = 3,5-dimethoxybenzoic acid; phen = 1,10-phenanthroline))were synthesized and characterized by elemental analysis, IR and TG/DSC-FTIR technology. Heat capacities of the four complexes were measured by differential scanning calorimetry (DSC). The antibacterial action of the four complexes on bacteria and fungus such as Escherichia coli, Staphylococcus aureus and Candida albicans were studied by filter paper approach. - Highlights: • Four novel complexes ([Ln(3,5-DmeoxBA){sub 3}(phen)]{sub 2} were synthesized and characterized. • The thermal decomposition processes of the title complexes were studied using the TG/DSC–FTIR coupling techniques. • The heat capacities of the complexes were measured by (DSC). • The antibacterial action of the four complexes on Escherichia coli, Staphylococcus aureus and Candida albicans were studied. - Abstract: Four lanthanide complexes with a general formula [Ln(3,5-DmeoxBA){sub 3}(phen)]{sub 2} (Ln = Tb(1), Dy(2), Er(3), Yb(4); 3,5-DmeoxBA = 3,5-dimethoxybenzoic acid; phen = 1,10-phenanthroline) were synthesized and characterized by elemental analysis, infrared spectra (IR), and thermogravimetric, differential scanning calorimetry techniques, combined with Fourier transform infrared (TG/DSC–FTIR) technology. The thermal decomposition processes of the four complexes were investigated by TG/DSC–FTIR techniques. Heat capacities were measured by DSC. The values of the experimental heat capacities were fitted to a polynomial equation with the least-squares method. Based on the fitted polynomial, the smoothed heat capacities and thermodynamic functions (H{sub T} − H{sub 298.15} {sub K}), (S{sub T} − S{sub 298.15} {sub K}), and (G{sub T} − G{sub 298.15} {sub K}) were calculated. The antibacterial action of the four complexes on bacteria and fungus such as Escherichia coli, Staphylococcus aureus and

  11. Characteristics of Trivalent Lanthanides in Coordination Chemistry

    Institute of Scientific and Technical Information of China (English)

    Xue Dongfeng(薛冬峰); Zuo Sen(左森); Henryk Ratajczak

    2004-01-01

    Some basic characteristics of lanthanide-oxygen bonds in various trivalent lanthanide metal-organic complexes are quantitatively studied by the bond valence model. Some important relationships among the electronegativity, bond valence parameter, bond length and lanthanide coordination number in these complexes are generally found , which show that for each trivalent lanthanide cation all calculated parameters may well be correlated with its coordination number in their coordination complexes. Specifically,32 new data for the bond valence parameter are first calculated in this work.An approximate linear relationship between the Ln-O bond valence parameter and the coordination number of Ln3+ is obtained.The Ln-O bond length increases with the increase in the lanthanide coordination number.The difference of electronegative values decreases with the increase in the lanthanide coordination number.

  12. Synthesis, magnetic and spectral studies of lanthanide(III) chloride complexes of hydrazones of isonicotinic acid hydrazide

    International Nuclear Information System (INIS)

    The synthesis, magnetic and spectral properties of trivalent lanthanide chlorides with N-isonicotinamidobenzalaldimine (INH-BENZ), N-isonicotinamidoanisalaldimine (INH-ANSL) and N-isonicotinamido-p-dimethylaminobenzalaldimine (INH-PDAB) are described. 13 refs., 2 tabs

  13. Synthesis and vibrational circular dichroism of enantiopure chiral oxorhenium(V) complexes containing the hydrotris(1-pyrazolyl)borate ligand

    DEFF Research Database (Denmark)

    Lassen, Peter Rygaard

    2006-01-01

    The infrared and vibrational circular dichroism (VCD) spectra of six chiral oxorhenium(V) complexes, bearing a hydrotris(1-pyrazolyl)borate (Tp) ligand, have been investigated. These complexes are promising candidates for observation of parity violation (symmetry breaking due to the weak nuclear ...

  14. Synthesis and Application of Lanthanide Complexes with Schiff Base of Pridoxylidence-Glycine

    Institute of Scientific and Technical Information of China (English)

    黄晓华; 周青; 王玉红; 王云翔; 李奚; 王小锋; 李邨

    2002-01-01

    A series of novel rare earths complexes with Schiff base of pridoxylidence-glycine acid (HL) were synthesized in absolute methanol under argon atmosphere. The complexes were characterized by elemental analysis, molar conductivity, IR, UV spectra, and H-NMR spectra et al. Data indicate that the complexes have a general formula Ln LCl2*3H2O (Ln=La, Y, Sm, Gd, Dy, Yb; L=C10H11N2O4). Effects of the complexes (Ln=La) on physiological and biochemical indexes of plants under Pb stress were studied. The experiments shown that the complexes obviously mitigated Pb pollution results in decreasing of chlorophyll content, rising of cell membrane permeability, changing catalase(CAT) and distribution of Pb.

  15. meso-Phenyltetrabenzotriazaporphyrin based double-decker lanthanide(III) complexes: synthesis, structure, spectral properties and electrochemistry.

    Science.gov (United States)

    Pushkarev, Victor E; Kalashnikov, Valery V; Tolbin, Alexander Yu; Trashin, Stanislav A; Borisova, Nataliya E; Simonov, Sergey V; Rybakov, Victor B; Tomilova, Larisa G; Zefirov, Nikolay S

    2015-10-01

    A series of half-sandwich and sandwich-type lanthanide(III) complexes have been prepared using tetrabenzotriazaporphyrin ligands. Reaction of 27-phenyl-29H,31H-tetrabenzo[b,g,l,q][5,10,15]-triazaporphyrin (PhTBTAPH2, 1) with salts [LnX3]·nH2O (Ln = Eu (a), Lu (b); X = OAc, acac) afforded the single- and homoleptic double-deckers (PhTBTAP)LnOAc (2) and (PhTBTAP)2Ln (3) respectively. Heteroleptic double-decker compounds (PhTBTAP)LnPc (4a,b) were obtained upon interaction of 1 with the corresponding Ln mono(phthalocyaninates). An unexpected formation of partially and completely dephenylated co-products 5 and 6 has been detected in the synthesis of sandwich 3, while the possibility of the dearylation of the half-sandwich compound 2 has been demonstrated as well. A more predictable yet firstly observed formation of the triple-decker compound (PhTBTAP)3Eu2 (7) has also been found. Structural studies of 3 supported by 1H NMR spectra, XRD analysis and DFT theoretical calculations reveal that the Eu complex 3a is formed as a single isomer, while the lutetium compound 3b represents an inseparable mixture of two rotational isomers with virtually identical spectral characteristics. The double-decker compounds 3 and 4 reveal intrinsic UV-Vis/NIR absorption as well as peculiar electrochromic behavior. The heteroleptic derivatives 4 generally show intermediate spectral and electrochemical properties with respect to their homoleptic relatives. PMID:26332086

  16. Complexation of lanthanide(III) and actinide(III) cations with tridentate nitrogen-donor ligands: A luminescence and spectro photometric study

    Energy Technology Data Exchange (ETDEWEB)

    Miguirditchian, M.; Guillaneux, D.; Fran is, N.; Airvault, S.; Ducros, S.; Thauvin, D. [CEA-Valrho, DEN/DRCP/SCPS, B.P. 17171, 30207 Bagnols-sur-Ceze Cedex (France); Madic, C. [CEA-Saclay, DEN/DDIN, 91191 Gif-sur-Yvette (France); Illemassene, M.; Lagarde, G.; Krupa, J.C. [Groupe de Radiochimie, Institut de Physique Nucleaire, 91405 Orsay (France)

    2006-07-01

    The complexation of lanthanide(III) (lanthanum, europium, and lutetium) and americium (III) by four tridentate nitrogen-donor ligands was investigated in homogeneous methanol/water solutions by using structural and thermodynamic approaches. The stoichiometry and inner-sphere hydration state of the europium complexes formed were determined by time-resolved laser-induced fluorimetry. The stability constants and in some cases the thermodynamic parameters were measured by ultraviolet-visible spectrophotometry and the van't Hoff method. The comparison of the stability constant of americium complexes with lanthanide complexes shows better stability for the actinide species. The strong affinity for these ligands toward Am{sup 3+} is confirmed by the formation of higher complexes, especially in the case of 2,6-bis-(5,6-dimethyl-1,2,4-triazine-3-yl)-pyridine (MeBTP), the only ligand able to form a 1:3 complex. The influence of the solvent composition on the complexation thermodynamics highlights the effect of the solvent reorganization on the reaction. (authors)

  17. Critical analysis of the data on complexation of lanthanides and actinides by natural organic matter: particular case of humic substances; Analyse critique des donnees de complexation des lanthanides et actinides par la matiere organique naturelle: cas des substances humiques

    Energy Technology Data Exchange (ETDEWEB)

    Reiller, P.

    2010-07-01

    This document proposes a critical analysis of the models that describe the actinides and lanthanides complexation by natural organic matter in general and by humic substances in particular. In order to better delimit the particular properties of these substances the most influent physical and chemical properties on complexation are recalled as a preamble. Models as well as data that has been used are reviewed, compiled, and eventually compared to independent data in order to identify (i) their application domain, (ii) the possible simplifications which permit to obtain operational models, (iii) the conditions in which simplifications cannot be ascertained yet, and (iv) the data or fields of knowledge which are still too uncertain. A comparison between the different models is proposed in order to adapt parameters from one model to another minimising the experimental acquisitions, or at least to focus on missing data. Usually, data on the complexation of free ions M{sup z+} are reliable; as soon as hydrolysis, or competition with another ligand in general, in at stake data are much less reliable. Predictions from models are much more uncertain: formation of mixed complexes with hydroxide or carbonate anions is not univocal whatever the modelling strategy. Hints for transfer functions between models which are believed to be incompatible could be explored in order to justify necessary simplifications for using operational modelling. Influence on the solubility of oxides could be quantified, but it is difficult to clearly separate it from colloidal particles stabilisation. The account of the competition between cations by the models has also been tested. In view of the small number of available experimental data there still lie some uncertainties especially for the media that are close to neutrality and in the case of competition with magnesium, but overall in the case of the competition with aluminium and iron. The influence of redox activity of humic substances is

  18. Complexation of biological ligands with lanthanides(III) for MRI: Structure, thermodynamic and methods

    International Nuclear Information System (INIS)

    New cyclic ligands derived from sugars and amino-acids form a scaffold carrying a coordination sphere of oxygen atoms suitable to complex Ln(III) ions. In spite of their rather low molecular weights, the complexes display surprisingly high relaxivity values, especially at high field. The ACX and BCX ligands, which are acidic derivatives of modified and cyclo-dextrins, form mono and bimetallic complexes with Ln(III). The LnACX and LnBCX complexes show affinities towards Ln(III) similar to those of tri-acidic ligands. In the bimetallic Lu2ACX complex, the cations are deeply embedded in the cavity of the ligand, as shown by the X-ray structure. In aqueous solution, the number of water molecules coordinated to the cation in the LnACX complex depends on the nature and concentration of the alkali ions of the supporting electrolyte, as shown by luminescence and relaxometric measurements. There is only one water molecule coordinated in the LnBCX complex, which enables us to highlight an important second sphere contribution to relaxivity. The NMR study of the RAFT peptidic ligand shows the complexation of Ln(III), with an affinity similar to those of natural ligands derived from calmodulin. The relaxometric study also shows an important second sphere contribution to relaxivity. To better understand the intricate molecular factors affecting relaxivity, we developed new relaxometric methods based on probe solutes. These methods allow us to determine the charge of the complex, weak affinity constants, trans-metallation constants, and the electronic relaxation rate. (author)

  19. Synthesis, characterization, DNA binding and cleavage studies of chiral Ru(II) salen complexes

    Science.gov (United States)

    Khan, Noor-ul H.; Pandya, Nirali; Kureshy, Rukhsana I.; Abdi, Sayed H. R.; Agrawal, Santosh; Bajaj, Hari C.; Pandya, Jagruti; Gupte, Akashya

    2009-09-01

    Interaction of chiral Ru(II) salen complexes (S)-1 and (R)-1 with Calf Thymus DNA (CT-DNA) was studied by absorption spectroscopy, competitive binding study, viscosity measurements, CD measurements, thermal denaturation study and cleavage studies by agarose gel electrophoresis. The DNA binding affinity of (S)-1 (6.25 × 10 3 M -1) was found to be greater than (R)-1 (3.0 × 10 3 M -1). The antimicrobial studies of these complexes on five different gram (+)/(-) bacteria and three different fungal organisms showed selective inhibition of the growth of gram (+) bacteria and were not affective against gram (-) and fungal organisms. Further, the (S)-1 enantiomer inhibited the growth of organisms to a greater extent as compared to (R)-1 enantiomer.

  20. A chiral Mn(IV) complex and its supramolecular assembly: Synthesis, characterization and properties

    Indian Academy of Sciences (India)

    Chullikkattil P Pradeep; Panthapally S Zacharias; Samar K Das

    2006-07-01

    The open air reaction of the chiral Schiff base ligand H2L, prepared by the condensation of L-phenylalaninol and 5-bromosalicylaldehyde, with MnII(CH3COO)2$\\cdot$4H2O yielded dark brown complex [MnIVL2]$\\cdot$0.5 DMF (1). Compound 1 was characterized by elemental analysis, IR, UV-visible, CD and EPR spectroscopy, cyclic voltammetry and room temperature magnetic moment determination. Singlecrystal X-ray analysis revealed that compound 1 crystallises in the monoclinic 21 space group with six mononuclear [MnIVL2] units in the asymmetric unit along with three solvent DMF molecules. In the crystal structure, each Mn(IV) complex, acting as the building unit, undergoes supramolecular linking through C-H$\\cdots$O bonds leading to an intricate hydrogen bonding network.

  1. Quenching of phosphorescence of some β-diketone complexes of lanthanides by oxygen at room temperature

    International Nuclear Information System (INIS)

    The phosphorescence quenching by oxygen of La, Y, Lu, Gd and Sc complexes with diketones:the iyltrifluoroacetone,acetylcetone, dibenzoylmethane and organic acids-pthalic, nicotinic, monochloroacetic and ethylenediaminetetraacetic ones is studied at room temperature. It is shown that air removal from the system and helium substitution fo; it do not change the type of phosphorescence spectrum but increase its intensity. The intensity of phosphorescence in the air of all simple β-diketonates of the elements is not high, except Gd complex with TTA. During the formation of ternary complexes the intensity increase is observed. The lowest increase in the phosphorescence intensity is observed in Gd and it increases in the series Gd-Lu-La-V-Sc. Helium substitution for air does not affect the duration of the phosphorescence quenching of double and ternary complexes of the metals studied

  2. Quantum mechanics and molecular dynamics simulations of complexation of alkaline-earth and lanthanide cations by poly-amino-carboxylate ligands; Simulations par mecanique quantique et dynamique moleculaire de la complexation de cations alcalino-terreux et lanthanides par des ligands polyaminocarboxylates

    Energy Technology Data Exchange (ETDEWEB)

    Durand, S

    1999-07-01

    Molecular dynamics (MD) simulations on lanthanide(III) and alkaline-earth(II) complexes with poly-amino-carboxylates (ethylene-diamino-tetra-acetate EDTA{sup 4-}, ethylene-diamino-tri-acetate-acetic acid EDTA(H){sup 3-}, tetra-aza-cyclo-dodecane-tetra-acetate DOTA{sup 4-}, methylene-imidine-acetate MIDA{sup 2-}) are reported. First, a consistent set of Lennard-Jones parameters for La{sup 3+}, Eu{sup 3+} and Lu{sup 3+} cations has been derived from free energy calculations in aqueous solution. Observed differences in hydration free energies, coordination distances and hydration numbers are reproduced. Then, the solution structures of 1:1 complexes of alkaline-earth and/or lanthanide cations with EDTA{sup 4-}, EDTA(H){sup 3-}, DOTA{sup 4-} and 1:2 complexes of lanthanide cations with MIDA{sup 2-} were studied by MD in water. In addition, free energy calculations were performed to study, for each ligand, the relative thermodynamic stabilities of complexes with Ca{sup 2+} vs Sr{sup 2+} and vs Ba{sup 2+} on the one hand, and with La{sup 3+} vs Eu{sup 3+} and vs Lu{sup 3+} on the other hand. Model does not take into account explicitly polarization and charge transfer. However, the results qualitatively agree with experimental complexation data (structure and selectivities). (author)

  3. Luminescent lanthanide complexes of a bis-bipyridine-phosphine-oxide ligand as tools for anion detection.

    Science.gov (United States)

    Charbonnière, Loïc J; Ziessel, Raymond; Montalti, Marco; Prodi, Luca; Zaccheroni, Nelsi; Boehme, Christian; Wipff, Georges

    2002-07-01

    The Gd(3+), Tb(3+), and Eu(3+) complexes of a bis-bipyridine-phenylphosphine oxide ligand PhP(O)(bipy)(2) 1 (bipy for 6-methylene-6'-methyl-2,2'-bipyridine) have been synthesized. In acetonitrile solutions at room temperature, the Tb(3+) and Eu(3+) complexes show a metal-centered luminescence, indicative of an efficient energy transfer from the two bipy subunits to the Ln center. The photophysical properties drastically depend on the nature of the anions present in solution. In particular, addition of 2 equiv of nitrate anions to a solution containing the [Ln.1](OTf-)(3) leads to an 11-fold increase of the luminescence intensity for the Eu(3+) and a 7-fold increase for the Tb(3+) complexes. Similar effects are provided with Cl-, F-, and CH(3)COO- anions. UV-vis titration experiments were used to determine association constants for binding of, respectively, one, two, and three anions. Stepwise anion addition has also been investigated on the molecular level using quantum mechanical (QM) calculations for the Eu complexes. These calculations reproduce the experimental findings, especially if solvent molecule addition is taken into account. The X-ray crystal structure of the nitrate salt of the Tb complex, as well as QM calculation of a similar Eu complex, demonstrates the coordination of three nitrate anions in a bidentate mode and the step-by-step relegation of the bipy subunits in the second coordination sphere. These features give valuable insights into the mechanism of the overall light amplification process. PMID:12083932

  4. Luminescent lanthanide complexes with 4-acetamidobenzoate: Synthesis, supramolecular assembly via hydrogen bonds, crystal structures and photoluminescence

    International Nuclear Information System (INIS)

    Four new luminescent complexes, namely, [Eu(aba)2(NO3)(C2H5OH)2] (1), [Eu(aba)3(H2O)2].0.5 (4, 4'-bpy).2H2O (2), [Eu2(aba)4(2, 2'-bpy)2(NO3)2].4H2O (3) and [Tb2(aba)4(phen)2(NO3)2].2C2H5OH (4) were obtained by treating Ln(NO3)3.6H2O and 4-acetamidobenzoic acid (Haba) with different coligands (4, 4'-bpy=4, 4'-bipyridine, 2, 2'-bpy=2, 2'-bipyridine, and phen=1, 10-phenanthroline). They exhibit 1D chains (1-2) and dimeric structures (3-4), respectively. This structural variation is mainly attributed to the change of coligands and various coordination modes of aba molecules. Moreover, the coordination units are further connected via hydrogen bonds to form 2D even 3D supramolecular networks. These complexes show characteristic emissions in the visible region at room temperature. In addition, thermal behaviors of four complexes have been investigated under air atmosphere. The relationship between the structures and physical properties has been discussed. - Graphical abstract: Structure variation of four complexes is attributed to the change of coligands and various coordination modes of aba molecules. Moreover, they show characteristic emissions in the visible region. Highlights: → Auxiliary ligands have played the crucial roles on the structures of the resulting complexes. → Isolated structure units are further assembled via H-bonds to form supramolecular networks. → These solid-state complexes exhibit strong, characteristic emissions in the visible region.

  5. Critical analysis of the data on complexation of lanthanides and actinides by natural organic matter: particular case of humic substances

    International Nuclear Information System (INIS)

    This document proposes a critical analysis of the models that describe the actinides and lanthanides complexation by natural organic matter in general and by humic substances in particular. In order to better delimit the particular properties of these substances the most influent physical and chemical properties on complexation are recalled as a preamble. Models as well as data that has been used are reviewed, compiled, and eventually compared to independent data in order to identify (i) their application domain, (ii) the possible simplifications which permit to obtain operational models, (iii) the conditions in which simplifications cannot be ascertained yet, and (iv) the data or fields of knowledge which are still too uncertain. A comparison between the different models is proposed in order to adapt parameters from one model to another minimising the experimental acquisitions, or at least to focus on missing data. Usually, data on the complexation of free ions Mz+ are reliable; as soon as hydrolysis, or competition with another ligand in general, in at stake data are much less reliable. Predictions from models are much more uncertain: formation of mixed complexes with hydroxide or carbonate anions is not univocal whatever the modelling strategy. Hints for transfer functions between models which are believed to be incompatible could be explored in order to justify necessary simplifications for using operational modelling. Influence on the solubility of oxides could be quantified, but it is difficult to clearly separate it from colloidal particles stabilisation. The account of the competition between cations by the models has also been tested. In view of the small number of available experimental data there still lie some uncertainties especially for the media that are close to neutrality and in the case of competition with magnesium, but overall in the case of the competition with aluminium and iron. The influence of redox activity of humic substances is also

  6. Highly Phosphorescent Crystals of Square-Planar Platinum Complexes with Chiral Organometallic Linkers: Homochiral versus Heterochiral Arrangements, Induced Circular Dichroism, and TD-DFT Calculations.

    Science.gov (United States)

    Sesolis, Hugo; Dubarle-Offner, Julien; Chan, Carmen K M; Puig, Emmanuel; Gontard, Geoffrey; Winter, Pierre; Cooksy, Andrew L; Yam, Vivian W W; Amouri, Hani

    2016-06-01

    A novel class of chiral luminescent square-planar platinum complexes with a π-bonded chiral thioquinonoid ligand is described. Remarkably the presence of this chiral organometallic ligand controls the aggregation of this square planar luminophor and imposes a homo- or hetero-chiral arrangement at the supramolecular level, displaying non-covalent Pt-Pt and π-π interactions. Interestingly these complexes are highly luminescent in the crystalline state and their photophysical properties can be traced to their aggregation in the solid state. A TD-DFT calculation is obtained to rationalize this unique behavior. PMID:27142245

  7. 3,4,3-LI(1,2-HOPO): In Vitro Formation of Highly Stable Lanthanide Complexes Translates into Efficacious In Vivo Europium Decorporation

    Energy Technology Data Exchange (ETDEWEB)

    Sturzbecher-Hoehne, Manuel; Ng Pak Leung, Clara; Daleo, Anthony; Kullgren, Birgitta; Prigent, Anne-Laure; Shuh, David K.; Raymond, Kenneth N.; Abergel, Rebecca J.

    2011-07-13

    The spermine-based hydroxypyridonate octadentate chelator 3,4,3-LI(1,2-HOPO) was investigated for its ability to act as an antennae that sensitizes the emission of Sm{sup III}, Eu{sup III}, and Tb{sup III} in the Visible range (Φ{sub tot} = 0.2 - 7%) and the emission of Pr{sup III}, Nd{sup III}, Sm{sup III}, and Yb{sup III} in the Near Infra-Red range, with decay times varying from 1.78 μs to 805 μs at room temperature. The particular luminescence spectroscopic properties of these lanthanide complexes formed with 3,4,3-LI(1,2-HOPO) were used to characterize their respective solution thermodynamic stabilities as well as those of the corresponding La{sup III}, Gd{sup III}, Dy{sup III}, Ho{sup III}, Er{sup III}, Tm{sup III}, and Lu{sup III} complexes. The remarkably high affinity of 3,4,3-LI(1,2-HOPO) for lanthanide metal ions and the resulting high complex stabilities (pM values ranging from 17.2 for La{sup III} to 23.1 for Yb{sup III}) constitute a necessary but not sufficient criteria to consider this octadentate ligand an optimal candidate for in vivo metal decorporation. The in vivo lanthanide complex stability and decorporation capacity of the ligand were assessed, using the radioactive isotope {sup 152}Eu as a tracer in a rodent model, which provided a direct comparison with the in vitro thermodynamic results and demonstrated the great potential of 3,4,3-LI(1,2-HOPO) as a therapeutic metal chelating agent.

  8. Stability of complexes of lanthanide trivalent ions with 8-hydroxyquinoline and its derivatives

    International Nuclear Information System (INIS)

    Linear dependence between acid dissociation (pKa) constants of 8-hydroxyquinoline and its derivatives and Hammett parameters determining contributions of induction and resonance effects of substituents is detected. It is found that correlation coefficients of earlier proposed equation determining the common change of stability in the rare earth series (Ln) from La to Lu, and also contributions of spin S and orbital L angle moments of Ln3+ to complex stability, relate linearly with Hammett constants of substituents in 8-hydroxyquinoline derivatives

  9. One-Pot Catalysis Using a Chiral Iridium Complex/Brønsted Base: Catalytic Asymmetric Synthesis of Catalponol.

    Science.gov (United States)

    Suzuki, Takeyuki; Ismiyarto; Ishizaka, Yuka; Zhou, Da-Yang; Asano, Kaori; Sasai, Hiroaki

    2015-11-01

    Tandem asymmetric hydrogen transfer oxidation/aldol condensation under relay catalysis of a chiral iridium complex/achiral Brønsted base binary system is described for the synthesis of α-benzylidene-γ-hydroxytetralones with high ee's. A two-step synthesis of catalponol was achieved using this sequential methodology together with regio- and stereoselective hydroboration. PMID:26496409

  10. Chiral metal complexes. 4. Stereoselective deuterium exchange at the coordinated NH/sub 2/ group of L-alanine

    Energy Technology Data Exchange (ETDEWEB)

    Vagg, R.S. (Macquarie Univ., North Ryde, Australia); Williams, P.A.

    1983-01-19

    This communication details results of initial /sup 1/H NMR investigations on one of the simplest of these ternary compounds, namely ..delta..,..lambda..-((L-alaninato)bis(2,2-bipyridine)ruthenium(II)) perchlorate. Possible mechanisms of deuterium exchange for chiral ruthenium complexes are presented in this study.

  11. Testing a generalized cooling procedure in the complex Langevin simulation of chiral Random Matrix Theory

    CERN Document Server

    Nagata, Keitaro; Shimasaki, Shinji

    2015-01-01

    The complex Langevin method has been attracting much attention as a solution to the sign problem since the method was shown to work in finite density QCD in the deconfined phase by using the so-called gauge cooling procedure. Whether it works also in the confined phase with light quarks is still an open question, though. In order to shed light on this question, we apply the method to the chiral Random Matrix Theory, which describes the epsilon regime of finite density QCD. Earlier works reported that a naive implementation of the method fails to reproduce the known exact results and that the problem can be solved by choosing a suitable coordinate. In this work we stick to the naive implementation, and show that a generalized gauge cooling procedure can be used to avoid the problem.

  12. Chirality of tensor perturbations for complex values of the Immirzi parameter

    Science.gov (United States)

    Bethke, Laura; Magueijo, João

    2012-03-01

    In this communication, we generalize previous work on tensor perturbations in a de Sitter background in terms of Ashtekar variables to cover all complex values of the Immirzi parameter γ (previous work was restricted to imaginary γ). Particular attention is paid to the case of real γ. Following the same approach as in the imaginary case, we can obtain physical graviton states by invoking reality and torsion-free conditions. The Hamiltonian in terms of graviton states has the same form whether γ has a real part or not; however, changes occur for the vacuum energy and fluctuations. Specifically, we observe a γ-dependent chiral asymmetry in the vacuum fluctuations only if γ has an imaginary part. Ordering prescriptions also change this asymmetry. We thus present a measurable result for CMB polarization experiments that could shed light on the workings of quantum gravity.

  13. Chirality of tensor perturbations for complex values of the Immirzi parameter

    International Nuclear Information System (INIS)

    In this communication, we generalize previous work on tensor perturbations in a de Sitter background in terms of Ashtekar variables to cover all complex values of the Immirzi parameter γ (previous work was restricted to imaginary γ). Particular attention is paid to the case of real γ. Following the same approach as in the imaginary case, we can obtain physical graviton states by invoking reality and torsion-free conditions. The Hamiltonian in terms of graviton states has the same form whether γ has a real part or not; however, changes occur for the vacuum energy and fluctuations. Specifically, we observe a γ-dependent chiral asymmetry in the vacuum fluctuations only if γ has an imaginary part. Ordering prescriptions also change this asymmetry. We thus present a measurable result for CMB polarization experiments that could shed light on the workings of quantum gravity. (fast track communication)

  14. Complexation of tetraza-scorpiand based aminopoly-carboxylates by lanthanide(III) ions

    International Nuclear Information System (INIS)

    Full text of publication follows. Owning to the fast complex formation reactions the open-chain ligands (DTPA derivatives) have been highly favored in the fields of biomedical (MRI) and radiopharmaceutical (RIT) applications. In order to overcome the slow complexation displayed by the macrocyclic ligands (e.g. DOTA) a few attempts have been made in the literature. Promising new chelators that integrate both macrocyclic and acyclic units ('hybrid' ligands) have already been designed (e.g. DETA)[Refs 1,2], but in spite of the large number of publications present in the scientific literature a rational explanation to the fast formation kinetic behavior is still missing. The lack of thermodynamic, formation and dissociation kinetic data for Ln3+ complexes persuaded us to synthesize some members of the given ligand class (e.g. DETA) and collect the aforementioned data. The presentation intends to focus on the results of ligand synthesis, equilibrium (stability constants of some biogenic Mg2+, Ca2+, Zn2+, Cu2+ and Ln3+ ions) and kinetics (detailed formation and dissociation) studies. The data obtained during the studies might help us to design new, better ligands for applications in nuclear medicine. References: 1] H.-S. Chong, et. al, Bioorg. Med. Chem. Letters, 2008, 18, 5792-5795; 2] H. A. Song et al., Bioconjugate Chem. 2011, 22, 1128-1135. Acknowledgements: The research was supported by the EU and co-financed by the European Social Fund (ESF) under the TAMOP-4.2.2./B-10/1-2010-0024 project. Support from the Hungarian National Science Foundation (OTKA K-84291), Hungarian Academy of Science (Janos Bolyai Research Scholarship), COST CM1006 and TD1004 Actions are also acknowledged. (authors)

  15. Magnetic Anisotropy and Spin-Parity Effect Along the Series of Lanthanide Complexes with DOTA

    OpenAIRE

    Boulon, Marie-Emmanuelle; Cucinotta, Giuseppe; Luzon, Javier; Degl'Innocenti, Chiara; Perfetti, Mauro; Bernot, Kevin; Calvez, Guillaume; Caneschi, Andrea; Sessoli, Roberta

    2012-01-01

    Spotting trends: Upon going from TbIII to YbIII centers in the complexes of the DOTA4- ligand, a reorientation of the easy axis of magnetization from perpendicular to parallel to the Ln-O bond of the apical water molecule is experimentally observed and theoretically predicted (see picture; SMM = single-molecule magnet). Only ions with an odd number of electrons show slow relaxation of the magnetization. © 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Complexation of trivalent lanthanides and other metal ions by 4-methoxybenzylidenepyruvate, in aqueous solution

    International Nuclear Information System (INIS)

    Complex formation equilibria involving M-4-MeO-BP binary systems in aqueous solution, where M=Y(III), La(III) to Lu(III), except Pm(III), Sc(III), Ga(III), In(III), Co(II), Ni(II), Cu(II), Pb(II), UO2(II) and Th(IV); 4-MeO-BP=4-methoxybenzylidenepyruvate have been investigated spectrophotometrically at 250C and ionic strength 0.500M. Coordination centres in 4-MeO-BP are suggested

  17. Covalent lanthanide(III) macrocyclic complexes: the bonding nature and optical properties of a promising single antenna molecule.

    Science.gov (United States)

    Rabanal-León, Walter A; Páez-Hernández, Dayán; Arratia-Pérez, Ramiro

    2014-12-21

    The present work is focused on the elucidation of the electronic structure, bonding nature and optical properties of a series of low symmetry (C2) coordination compounds of type [Ln(III)HAM](3+), where "Ln(III)" are the trivalent lanthanide ions: La(3+), Ce(3+), Eu(3+) and Lu(3+), while "HAM" is the neutral six-nitrogen donor macrocyclic ligand [C22N6H26]. This systematic study has been performed in the framework of the Relativistic Density Functional Theory (R-DFT) and also using a multi-reference approach via the Complete Active Space (CAS) wavefunction treatment with the aim of analyzing their ground state and excited state electronic structures as well as electronic correlation. Furthermore, the use of the energy decomposition scheme proposed by Morokuma-Ziegler and the electron localization function (ELF) allows us to characterize the bonding between the lanthanide ions and the macrocyclic ligand, obtaining as a result a dative-covalent interaction. Due to a great deal of lanthanide optical properties and their technological applications, the absorption spectra of this set of coordination compounds were calculated using the time-dependent density functional theory (TD-DFT), where the presence of the intense Ligand to Metal Charge Transfer (LMCT) bands in the ultraviolet and visible region and the inherent f-f electronic transitions in the Near-Infra Red (NIR) region for some lanthanide ions allow us to propose these systems as "single antenna molecules" with potential applications in NIR technologies. PMID:25357209

  18. 2,4-Dichlorophenoxyacetic Acid Derived Schiff Base and Its Lanthanide(III Complexes: Synthesis, Characterization, Spectroscopic Studies, and Plant Growth Activity

    Directory of Open Access Journals (Sweden)

    Ganesh N. Naik

    2013-01-01

    Full Text Available 2,4-Dichlorophenoxyacetic acid derived Schiff base (HL and its lanthanide [La(III, Pr(III, Nd(III, Sm(III, Eu(III, Gd(III, Dy(III, Y(III] complexes were synthesized and characterized by various spectroscopic (1H, 13C, DEPT and 2D HMQC NMR, FT-IR, UV-Vis, and mass techniques and other analytical methods. HL exhibits “E” and “Z” isomerism and was confirmed by variable temperature 1H NMR studies. The spectral and analytical data reveals the bidentate coordination of HL to lanthanide(III ion, through carboxylic acid group via deprotonation. Fluorescence spectrum of europium complex shows bands at 578, 592, and 612 nm assignable to D05→F07, D05→F17, and D05→F27, respectively. Auxin activity of HL and lanthanum(III complex on wheat seeds (Triticum durum was measured at different concentrations. The percentage germination, root length, and shoot length were recorded. An enhancement in the plant growth activity of the ligand was observed on complexation and the best activity was observed at 10−6 M concentration.

  19. Vibrational circular dichroism and chiroptical properties of chiral Ir(iii) luminescent complexes.

    Science.gov (United States)

    Mazzeo, Giuseppe; Fusè, Marco; Longhi, Giovanna; Rimoldi, Isabella; Cesarotti, Edoardo; Crispini, Alessandra; Abbate, Sergio

    2016-01-21

    The octahedral ionic Ir(iii) complex with a dual stereogenic centre of general formula Δ,Λ-(R,S)-[(ppy)2Ir(Me-Campy)]X, where ppy = 2-phenylpyridine and Me-Campy = 2-methyl-5,6,7,8-tetrahydroquinolin-8-amine, and the complex Λ-(R,S)-[(ppy)2Ir(H-Campy)]X, where ppy = 2-phenylpyridine, H-Campy = 8-amino-5,6,7,8-tetrahydroquinolines and X(-) = Cl(-) as a counterion in both cases, have been characterized by vibrational circular dichroism (VCD), which turns out to be efficacious in diastereomeric discrimination. Moreover, the single crystal X-ray structure of the complex Δ-(R)-[(ppy)2Ir(Me-Campy)]Cl is reported here. Density functional theory (DFT) calculations allow us to conclude that the most important doublet feature in the VCD spectra is associated with a clear vibrational exciton structure located on the two dissymmetrically disposed phenylpyridine ligands. The features in the VCD spectra associated with the (R) or (S)-central chirality configuration are identified and commented on. DFT calculations provide also the interpretation of electronic circular dichroism (ECD) spectra. Finally, circularly polarized luminescence (CPL) spectra are presented as an additional chiroptical characterization of these luminescent iridium complexes. PMID:26647994

  20. One ligand fits all: lanthanide and actinide sandwich complexes comprising the 1,4-bis(trimethylsilyl)cyclooctatetraenyl (=COT′′) ligand

    OpenAIRE

    RAUSCH Janek; Apostolidis, Christos; WALTER OLAF; Lorenz, Volker; HRIB Cristian; Hilfert, Liane; KÜHLING Marcel; BUSSE Sabine; Edelmann, Frank

    2015-01-01

    The series of anionic lanthanide(III) sandwich complexes of the type [Ln(COT'')2]- (COT'' = 1,4-bis(trimethylsilyl)cyclooctatetraenyl dianion) has been largely extended by the synthesis of eight new derivatives ranging from lanthanum to lutetium. The new compounds [Li(DME)3][Ln(COT'')2] (Ln = Y (1), La (2), Pr (3), Gd (4), Tm (6), Lu (8)) and [Li(THF)4][Ln(COT'')2] (Ln = Ho (5), Tm (7)) were prepared in good yields following a straightforward synthetic protocol which involves treatment of LnC...

  1. A chiral rhenium complex with predicted high parity violation effects: synthesis, stereochemical characterization by VCD spectroscopy and quantum chemical calculations

    CERN Document Server

    Saleh, Nidal; Roisnel, Thierry; Guy, Laure; Bast, Radovan; Saue, Trond; Darquié, Benoît; Crassous, Jeanne

    2015-01-01

    With their rich electronic, vibrational, rotational and hyperfine structure, molecular systems have the potential to play a decisive role in precision tests of fundamental physics. For example, electroweak nuclear interactions should cause small energy differences between the two enantiomers of chiral molecules, a signature of parity symmetry breaking. Enantioenriched oxorhenium(VII) complexes S-(-)- and R-(+)-3 bearing a chiral 2-methyl-1-thio-propanol ligand have been prepared as potential candidates for probing molecular parity violation effects via high resolution laser spectroscopy of the Re=O stretching. Although the rhenium atom is not a stereogenic centre in itself, experimental vibrational circular dichroism (VCD) spectra revealed a surrounding chiral environment, evidenced by the Re=O bond stretching mode signal. The calculated VCD spectrum of the R enantiomer confirmed the position of the sulfur atom cis to the methyl, as observed in the solid-state X-ray crystallographic structure, and showed the ...

  2. Complexation thermodynamics and structural studies of trivalent actinide and lanthanide complexes with DTPA, MS-325 and HMDTPA

    International Nuclear Information System (INIS)

    The protonation constants of DTPA (diethylenetriaminepentaacetic acid) and two derivatives of DTPA, 1-R(4,4-diphenyl cyclohexyl-phosphonyl-methyl diethylenentriaminepentaacetic acid) (MS-325) and (R)-hydroxymethyl-diethylenentriaminepentaacetic acid (HMDTPA) were determined by potentiometric titration in 0.1 M NaClO4. The formation of 1: 1 complexes of Am3+, Cm3+ and Ln3+ cations with these three ligands were investigated by potentiometric titration with competition by ethylenediaminetetraacetic acid (EDTA) and the solvent extraction method in aqueous solutions of I=0.10 M NaClO4. The thermodynamic data of complexation were determined by the temperature dependence of the stability constants and by calorimetry. The complexation is exothermic and becomes weaker with increase in temperature. The complexation strength of these ligands follows the order: DTPA ∼ HMDTPA > MS-325. Eu3+/Cm3+ luminescence, EXAFS (Extended X-ray Absorption Fine Structure) and DFT (Density Functional Theory) calculations suggest that all three ligands are octadentate in the complex. In the complex, M(L)2- (L = DTPA, MS-325 and HMDTPA). The M3+ binds via five carboxylates oxygen atoms, three nitrogen atoms, and the complex contains one water of hydration. (orig.)

  3. Enantiomeric pair of copper(II) polypyridyl-alanine complexes: Effect of chirality on their interaction with biomolecules.

    Science.gov (United States)

    Ng, Chew Hee; Chan, Cheang Wei; Lai, Jing Wei; Ooi, Ing Hong; Chong, Kok Vei; Maah, Mohd Jamil; Seng, Hoi Ling

    2016-07-01

    Like chiral organic drugs, the chemical and biological properties of metal complexes can be dependent on chirality. Two pairs of [Cu(phen)(ala)(H2O)]X·xH2O (phen=1.10-phenanthroline: X=NO3(-); ala: l-alanine (l-ala), 1 and d-alanine (d-ala) 2; and (X=Cl(-); ala: l-ala, 3 and d-ala, 4) complex salts (x=number of lattice water molecules) have been synthesized and characterized. The crystal structure of 3 has been determined. The same pair of enantiomeric species, viz. [Cu(phen)(l-ala)(H2O)](+) and [Cu(phen)(d-ala)(H2O)](+), have been identified to be present in the aqueous solutions of both 1 and 3, and in those of both 2 and 4 respectively. Both 3 and 4 bind more strongly to ds(AT)6 than ds(CG)6. There is no or insignificant effect of the chirality of 3 and 4 on the production of hydroxyl radicals, binding to deoxyribonucleic acid from calf thymus (CT-DNA), ds(CG)6, G-quadruplex and 17-base pair duplex, and inhibition of both topoisomerase I and proteasome. Among the three proteasome proteolytic sites, the trypsin-like site is inhibited most strongly by these complexes. However, the chirality of 3 and 4 does affect the number of restriction enzymes inhibited, and their binding constants towards ds(AT)6 and serum albumin. PMID:27105312

  4. Characterization of partitioning relevant lanthanide and actinide complexes by NMR spectroscopy; Charakterisierung von partitioningrelevanten Lanthaniden- und Actinidenkomplexen mittels NMR-Spektroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Adam, Christian

    2016-01-15

    In the present work the interaction of N-donor ligands, such as 2,6-Bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine (nPrBTP) and 2,6-Bis(5-(2,2-dimethylpropyl)1H-pyrazol)-3-yl-pyridine (C5-BPP), with trivalent lanthanide and actinide ions was studied. Ligands of this type show a high selectivity for the separation of trivalent actinide ions over lanthanides from nitric acid solutions. However, the reason for this selectivity, which is crucial for future partitioning and transmutation strategies for radioactive wastes, is still unknown. So far, the selectivity of some N-donor ligands is supposed to be an effect of an increased covalency in the actinide-ligand bond, compared to the lanthanide compounds. NMR spectroscopy on paramagnetic metal complexes is an excellent tool for the elucidation of bonding modes. The overall paramagnetic chemical shift consists of two contributions, the Fermi Contact Shift (FCS), due to electron spin delocalisation through covalent bonds, and the Pseudo Contact Shift (PCS), which describes the dipolar coupling of the electron magnetic moment and the nuclear spin. By assessing the FCS share in the paramagnetic shift, the degree of covalency in the metal-ligand bond can be gauged. Several methods to discriminate FCS and PCS have been used on the data of the nPrBTP- and C5-BPP-complexes and were evaluated regarding their applicability on lanthanide and actinide complexes with N-donor ligands. The study comprised the synthesis of all Ln(III) complexes with the exceptions of Pm(III) and Gd(III) as well as the Am(III) complex as a representative of the actinide series with both ligands. All complexes were fully characterised ({sup 1}H, {sup 13}C and {sup 15}N spectra) using NMR spectroscopy. By isotope enrichment with the NMR-active {sup 15}N in positions 8 and 9 in both ligands, resonance signals of these nitrogen atoms were detected for all complexes. The Bleaneymethod relies on different temperature dependencies for FCS (T{sup -1}) and PCS (T

  5. Hybrid materials of MCM-41 functionalized by lanthanide (Tb3+, Eu3+) complexes of modified meta-methylbenzoic acid: Covalently bonded assembly and photoluminescence

    International Nuclear Information System (INIS)

    Novel organic-inorganic mesoporous hybrid materials were synthesized by linking lanthanide (Tb3+, Eu3+) complexes to the mesoporous MCM-41 through the modified meta-methylbenzoic acid (MMBA-Si) using co-condensation method in the presence of the cetyltrimethylammonium bromide (CTAB) surfactant as template. The luminescence properties of these resulting materials (denoted as Ln-MMBA-MCM-41, Ln=Tb, Eu) were characterized in detail, and the results reveal that luminescent mesoporous materials have high surface area, uniformity in the ordered mesoporous structure. Moreover, the mesoporous material covalently bonded Tb3+ complex (Tb-MMBA-MCM-41) exhibits the stronger characteristic emission of Tb3+ and longer lifetime than Eu-MMBA-MCM-41 due to the triplet state energy of organic legend MMBA-Si matches with the emissive energy level of Tb3+ very well. - Graphical abstract: Novel organic-inorganic mesoporous luminescent materials were synthesized by linking lanthanide (Tb3+, Eu3+) complexes to covalently bond the functionalized ordered mesoporous MCM-41 with modified meta-methylbenzoic acid (MMBA)-Si by co-condensation of tetraethoxysilane (TEOS) in the presence of the cetyltrimethylammonium bromide (CTAB) surfactant as template

  6. Crystallization of the pneumococcal autolysin LytC: in-house phasing using novel lanthanide complexes

    International Nuclear Information System (INIS)

    The complete pneumococcal autolysin LytC has been crystallized by the hanging-drop vapor-diffusion method. A SAD data set has been collected in-house from a Gd derivative up to 2.6 Å resolution. LytC, one of the major autolysins from the human pathogen Streptococcus pneumoniae, has been crystallized as needles by the hanging-drop technique using 10%(w/v) PEG 3350 as precipitant and 10 mM HEPES pH 7.5. LytC crystals were quickly soaked in mother liquor containing 2 mM of the complex Gd-HPDO3A to produce derivatized crystals (LytCGd-HPDO3A). Both native LytC and isomorphous LytCGd-HPDO3A crystals were flash-cooled in a nitrogen flow at 120 K prior to X-ray data collection using an in-house Enraf–Nonius rotating-anode generator (λ = 1.5418 Å) and a MAR345 imaging-plate detector. In both cases, good-quality diffraction patterns were obtained at high resolution. LytCGd-HPDO3A crystals allowed the collection of a SAD X-ray data set to 2.6 Å resolution indexed in terms of a P21 monoclinic unit cell with parameters a = 59.37, b = 67.16, c = 78.85 Å, β = 105.69°. The anomalous Patterson map allowed the identification of one heavy-atom binding site, which was sufficient for the calculation of an interpretable anomalous map at 2.6 Å resolution

  7. From antenna to assay: lessons learned in lanthanide luminescence.

    Science.gov (United States)

    Moore, Evan G; Samuel, Amanda P S; Raymond, Kenneth N

    2009-04-21

    Ligand-sensitized, luminescent lanthanide(III) complexes are of considerable importance because their unique photophysical properties (microsecond to millisecond lifetimes, characteristic and narrow emission bands, and large Stokes shifts) make them well suited as labels in fluorescence-based bioassays. The long-lived emission of lanthanide(III) cations can be temporally resolved from scattered light and background fluorescence to vastly enhance measurement sensitivity. One challenge in this field is the design of sensitizing ligands that provide highly emissive complexes with sufficient stability and aqueous solubility for practical applications. In this Account, we give an overview of some of the general properties of the trivalent lanthanides and follow with a summary of advances made in our laboratory in the development of highly luminescent Tb(III) and Eu(III) complexes for applications in biotechnology. A focus of our research has been the optimization of these compounds as potential commercial agents for use in homogeneous time-resolved fluorescence (HTRF) technology. Our approach involves developing high-stability octadentate Tb(III) and Eu(III) complexes that rely on all-oxygen donor atoms and using multichromophore chelates to increase molar absorptivity; earlier examples utilized a single pendant chromophore (that is, a single "antenna"). Ligands based on 2-hydroxyisophthalamide (IAM) provide exceptionally emissive Tb(III) complexes with quantum yield values up to approximately 60% that are stable at the nanomolar concentrations required for commercial assays. Through synthetic modification of the IAM chromophore and time-dependent density functional theory (TD-DFT) calculations, we have developed a method to predict absorption and emission properties of these chromophores as a tool to guide ligand design. Additionally, we have investigated chiral IAM ligands that yield Tb(III) complexes possessing both high quantum yield values and strong circularly

  8. Luminescence, magnetocaloric effect and single-molecule magnet behavior in lanthanide complexes based on a tridentate ligand derived from 8-hydroxyquinoline.

    Science.gov (United States)

    Shen, Hai-Yun; Wang, Wen-Min; Bi, Yan-Xia; Gao, Hong-Ling; Liu, Shuang; Cui, Jian-Zhong

    2015-11-21

    A new family of lanthanide complexes, [Ln2(hfac)4L2] (Ln = Eu (1), Gd (2), Tb (3), Dy (4), Ho (5), Er (6), Lu (7); hfac = hexafluoroacetylacetonate, HL = 2-(2′-benzothiazole)-8-hydroxyquinoline), was synthesized and characterized using single-crystal X-ray diffraction, elemental analysis (EA), thermal gravimetric analysis (TGA), powder X-ray diffraction (PXRD) and UV-vis spectra. X-ray crystallographic analyses reveal that 1–7 are isomorphous and crystallize in the monoclinic space group C2/c. In these dinuclear complexes, each LnШ ion is eight-coordinated with two bidentate hfac and two μ-phenol bridging L ligands. The TGA results show that the complexes have relatively high thermal stabilities. Complexes 1 and 3 show the characteristic transitions of the corresponding lanthanide ions with ligand-related emission peaks. Meanwhile, complexes 4 and 7 exhibit ligand-centered fluorescence at room temperature. Magnetic measurements were carried out on complexes 2–6. The magnetic study reveals that 2 displays a magnetocaloric effect, with a maximum −ΔSm value of 16.89 J K−1 kg−1 at 2 K for ΔH = 8 T. Dynamic magnetic studies reveal single-molecule magnet (SMM) behavior for complex 4. Fitting the dynamic magnetic data to the Arrhenius law gives an energy barrier ΔE/kB = 50.33 K and pre-exponential factor τ0 = 1.05 × 10(-8)s. PMID:26466301

  9. Luminescent hybrid materials based on zeolite L crystals and lanthanide complexes: Host-guest assembly and ultraviolet-visible excitation

    Science.gov (United States)

    Chen, Lei; Yan, Bing

    2014-10-01

    Several kinds of host-guest hybrid materials have been synthesized employing a ship in a bottle method by loading 9-hydroxy-2-methylphenalenone (MHPO) or 9-hydroxyphenalen (HPNP) from gas phase into the nanochannels of Ln3+-exchanged zeolite L (ZL) crystals (Ln = Gd or Eu). The resulting hybrids without lanthanide ions, MHPO-ZL, HPNP-ZL and the hybrids with lanthanide ions Ln-MHPO-ZL and Ln-HPNP-ZL are characterized with FT-IR, UV-vis DRS and photoluminescence spectroscopy. The photoluminescence properties of these hybrid materials have been analyzed and discussed, exhibiting the luminescence of Eu3+ and ligands under the excitation at ultraviolet-visible region. These results provide useful data and can be expected to have potential application in the practical fields.

  10. Coordination Complexes of Decamethylytterbocene with 4,4'-Disubstituted Bipyridines: An Experimental Study of Spin Coupling in Lanthanide Complexes

    OpenAIRE

    Walter, Marc D.; Berg, David J.; Andersen, Richard A.

    2005-01-01

    The paramagnetic 1:1 coordination complexes of (C5Me5)2Yb with a series of 4,4'-disubstituted bipyridines, bipy-X, where X is Me, tert-Bu, OMe, Ph, CO2Me, and CO2Et have been prepared. All of the complexes are paramagnetic and the values of the magnetic susceptibility as a function of temperature show that these values are less than expected for the cation, [(C5Me5)2Yb(III)(bipy-X)]+, which have been isolated as the cation-anion ion-pairs [(C5Me5)2Yb(III)(bipy-X)]+[(C5Me5)2YbI2]f fnfn wh...

  11. Low-voltage organic field-effect transistors based on novel high-κ organometallic lanthanide complex for gate insulating materials

    Directory of Open Access Journals (Sweden)

    Qi Liu

    2014-08-01

    Full Text Available A novel high-κ organometallic lanthanide complex, Eu(tta3L (tta=2-thenoyltrifluoroacetonate, L = 4,5-pinene bipyridine, is used as gate insulating material to fabricate low-voltage pentacene field-effect transistors (FETs. The optimized gate insulator exhibits the excellent properties such as low leakage current density, low surface roughness, and high dielectric constant. When operated under a low voltage of −5 V, the pentacene FET devices show the attractive electrical performance, e.g. carrier mobility (μFET of 0.17 cm2 V−1 s−1, threshold voltage (Vth of −0.9 V, on/off current ratio of 5 × 103, and subthreshold slope (SS of 1.0 V dec−1, which is much better than that of devices obtained on conventional 300 nm SiO2 substrate (0.13 cm2 V−1 s−1, −7.3 V and 3.1 V dec−1 for μFET, Vth and SS value when operated at −30 V. These results indicate that this kind of high-κ organometallic lanthanide complex becomes a promising candidate as gate insulator for low-voltage organic FETs.

  12. Low-voltage organic field-effect transistors based on novel high-κ organometallic lanthanide complex for gate insulating materials

    International Nuclear Information System (INIS)

    A novel high-κ organometallic lanthanide complex, Eu(tta)3L (tta=2-thenoyltrifluoroacetonate, L = 4,5-pinene bipyridine), is used as gate insulating material to fabricate low-voltage pentacene field-effect transistors (FETs). The optimized gate insulator exhibits the excellent properties such as low leakage current density, low surface roughness, and high dielectric constant. When operated under a low voltage of −5 V, the pentacene FET devices show the attractive electrical performance, e.g. carrier mobility (μFET) of 0.17 cm2 V−1 s−1, threshold voltage (Vth) of −0.9 V, on/off current ratio of 5 × 103, and subthreshold slope (SS) of 1.0 V dec−1, which is much better than that of devices obtained on conventional 300 nm SiO2 substrate (0.13 cm2 V−1 s−1, −7.3 V and 3.1 V dec−1 for μFET, Vth and SS value when operated at −30 V). These results indicate that this kind of high-κ organometallic lanthanide complex becomes a promising candidate as gate insulator for low-voltage organic FETs

  13. Dynamics of the layer-by-layer assembly of a poly(acrylic acid)-lanthanide complex colloid and poly(diallyldimethyl ammonium).

    Science.gov (United States)

    Xu, Jiali; Wang, Zhiliang; Wen, Lingang; Zhou, Xianju; Xu, Jian; Yang, Shuguang

    2016-01-21

    Poly(acrylic acid) (PAA) and lanthanide (Ln) ions, such as Ce(3+), Eu(3+), and Tb(3+), were prepared as dispersed complex colloidal particles through three different protocols with rigorous control of the pH value and mixing ratio. The negatively charged PAA-Ln complex particles were layer-by-layer (LbL) assembled with positively charged poly(diallyldimethyl ammonium) (PDDA) to prepare a thin film. The film thickness growth is much quicker than PDDA/PAA film. Due to the incorporation of Ln(3+) ions, the film exhibits fluorescence. During LbL assembly, PDDA-PAA association based on electrostatic force and PAA-Ce association based on coordination are in competition, which leads to the LbL assembly of PDDA and PAA-Ln complex colloidal particles being a complicated dynamic process. PMID:26549538

  14. Synthesis, structure and properties of lanthanide(III) picrate complexes with trans-1,4-dithiane-1,4-dioxide (TDTD)

    International Nuclear Information System (INIS)

    A series of isomorphous lanthanide complexes, having general formula M(pic)3(TDTD)1.5 (M=Ce-Er, Yb and Y), was synthesized and characterized by microanalyses, infrared spectra and visible emission spectrum for the Eu complex. Crystal structures were determined for the Ce and Eu derivatives; for the other complexes only cell parameters were obtained and reported. The compounds crystallize with a monoclinic cell, space group P21/c with Z=4. The metal ions are nine-coordinated with a tricapped trigonal prismatic coordination polyhedron, achieved via the bonding of three bidentate picrate units and three oxygens of the TDTD ligands. The TDTD moieties are shared by adjacent metal centers, forming three-dimensional polymers. (orig.)

  15. Ligand Field Affected Single-Molecule Magnet Behavior of Lanthanide(III) Dinuclear Complexes with an 8-Hydroxyquinoline Schiff Base Derivative as Bridging Ligand.

    Science.gov (United States)

    Wang, Wen-Min; Zhang, Hong-Xia; Wang, Shi-Yu; Shen, Hai-Yun; Gao, Hong-Ling; Cui, Jian-Zhong; Zhao, Bin

    2015-11-16

    New dinuclear lanthanide(III) complexes based on an 8-hydroxyquinoline Schiff base derivative and β-diketonate ligands, [Ln2(hfac)4(L)2] (Ln(III) = Gd (1), Tb (2), Dy (3), Ho (4), Er (5)), [Ln2(tfac)4(L)2] (Ln(III) = Gd (6), Tb (7), Dy (8), Ho (9)), and [Dy(bfac)4(L)2·C7H16] (10) (L = 2-[[(4-fluorophenyl)imino] methyl]-8-hydroxyquinoline, hfac = hexafluoroacetylacetonate, tfac = trifluoroacetylacetonate, and bfac = benzoyltrifluoroacetone), have been synthesized. The single-crystal X-ray diffraction data show that complexes 1-10 are phenoxo-O-bridged dinuclear complexes; each eight-coordinated center Ln(III) ion is in a slightly distorted dodecahedral geometry with two bidentate β-diketonate coligands and two μ2-O bridging 8-hydroxyquinoline Schiff base derivative ligands. The magnetic study reveals that 1 and 6 display cryogenic magnetic refrigeration properties, whereas complexes 3, 8, and 10 show different SMM behaviors with energy barriers of 6.77 K for 3, 19.83 K for 8, and 25.65 K for 10. Meanwhile, slow magnetic relaxation was observed in 7, while no out-of-phase alternating-current signals were found for 2. The different dynamic magnetic behaviors of two Tb2 complexes and the three Dy2 complexes mainly derive from the tiny crystal structure changes around the Ln(III) ions. It is also proved that the β-diketonate coligands can play an important role in modulating magnetic dynamics of the lanthanide 8-hydroxyquinoline Schiff base derivative system. PMID:26516660

  16. Lanthanides in the frame of Molecular Magnetism

    Directory of Open Access Journals (Sweden)

    Gatteschi D.

    2014-07-01

    Full Text Available Molecular magnetism is producing new types of materials which cover up to date aspects of basic science together with possible applications. This article highlights recent results from the point of view of lanthanides which are now intensively used to produce single molecule magnets, single chain and single ion magnets. After a short introduction reminding the main steps of development of molecular magnetism, the basic properties of lanthanides will be covered highlighting important features which are enhanced by the electronic structure of lanthanides, like spin frustration and chirality, anisotropy and non collinear axes in zero and one dimensional materials. A paragraph of conclusions will discuss what has been done and theperspectives to be expected.

  17. Method bacterial endospore quantification using lanthanide dipicolinate luminescence

    Science.gov (United States)

    Ponce, Adrian (Inventor); Venkateswaran, Kasthuri J. (Inventor); Kirby, James Patrick (Inventor)

    2007-01-01

    A lanthanide is combined with a medium to be tested for endospores. The dipicolinic acid released from the endospores binds the lanthanides, which have distinctive emission (i.e., luminescence) spectra, and are detected using photoluminescence. The concentration of spores is determined by preparing a calibration curve generated from photoluminescence spectra of lanthanide complex mixed with spores of a known concentration. A lanthanide complex is used as the analysis reagent, and is comprised of lanthanide ions bound to multidentate ligands that increase the dipicolinic acid binding constant through a cooperative binding effect with respect to lanthanide chloride. The resulting combined effect of increasing the binding constant and eliminating coordinated water and multiple equilibria increase the sensitivity of the endospore assay by an estimated three to four orders of magnitude over prior art of endospore detection based on lanthanide luminescence.

  18. Understanding the photophysical properties of chiral dinuclear Re(i) complexes and the role of Re(i) in their complexes.

    Science.gov (United States)

    Liu, Chunyu; Si, Yanling; Shi, Shaoqing; Yang, Guochun; Pan, Xiumei

    2016-05-01

    Chiral transition metal complexes not only have large nonlinear optical (NLO) response but also meet the non-centrosymmetric requirement of second-order NLO materials. Therefore, chiral transition metal complexes become very active in the NLO area. Recently, the second-order NLO response of chiral dinuclear Re(i) complex 2 has been found to be 1.5 times larger than that of KH2PO4 (KDP) based on experimental measurement. However, its NLO origin has not been determined and a structure-property relationship has not been established at the microscopic level, which are very important to further improve the performance. It is found that charge transfer from metal to ligand is mainly responsible for its NLO origin. Based on complex 2, the designed complexes have remarkably large second-order NLO activity. For instance, the designed complex 9 has a very large second-order NLO response value (115.81 × 10(-30) esu), which is about 668 times larger than the organic molecule urea. Moreover, time-dependent density functional theory (TDDFT) calculations have been used to investigate their UV-Vis/CD spectra. The simulated circular dichroism (CD) spectra of the complex 2 are in good agreement with the experimental ones, which can be used to assign the absolute configurations (ACs) of chiral dinuclear Re(i) complexes with high confidence. The electronic absorption wavelengths, electron transition properties, and the second-order NLO responses strongly depend on the nature of substituent, different ligands (pyridine and isoquinoline) and their combinations. Based on NBO analysis, the interactions between [Re(CO)3Cl] fragments and ligands are of n →σ* character. PMID:27009569

  19. Predicting Chiral Nanostructures, Lattices and Superlattices in Complex Multicomponent Nanoparticle Self-Assembly

    KAUST Repository

    Hur, Kahyun

    2012-06-13

    "Bottom up" type nanoparticle (NP) self-assembly is expected to provide facile routes to nanostructured materials for various, for example, energy related, applications. Despite progress in simulations and theories, structure prediction of self-assembled materials beyond simple model systems remains challenging. Here we utilize a field theory approach for predicting nanostructure of complex and multicomponent hybrid systems with multiple types of short- and long-range interactions. We propose design criteria for controlling a range of NP based nanomaterial structures. In good agreement with recent experiments, the theory predicts that ABC triblock terpolymer directed assemblies with ligand-stabilized NPs can lead to chiral NP network structures. Furthermore, we predict that long-range Coulomb interactions between NPs leading to simple NP lattices, when applied to NP/block copolymer (BCP) assemblies, induce NP superlattice formation within the phase separated BCP nanostructure, a strategy not yet realized experimentally. We expect such superlattices to be of increasing interest to communities involved in research on, for example, energy generation and storage, metamaterials, as well as microelectronics and information storage. © 2012 American Chemical Society.

  20. Correlation in the lanthanide series

    International Nuclear Information System (INIS)

    The correlations lgK vs. lgK', V vs. V' (K - stability constant of the complex, V - unit cell volume of compound) within the lanthanide tetrads were reviewed. Ligands with - C = N-group were found to show a positive deviation from the lgK vs. lgK' plot. (Author)

  1. Separation of lanthanides through hydroxyapatite

    International Nuclear Information System (INIS)

    With the objective of obtaining from an independent way to each one of the lanthanides 151 Pm, 161 Tb, 166 Ho and 177 Lu free of carrier and with high specific activities starting from the indirect irradiation via, it intends in this work to determine the viability of separation of the couples Nd/Pm, Dy/Ho, Gd/Tb and Yb/Lu, by means of ion exchange column chromatography, using hydroxyapatite (HAp) and fluorite like absorbent material in complexing media. It is important to mention that have registered separation studies among lanthanides of the heavy group with those of the slight group, using the same mass and, in comparison with this work, quantities different from the father were used and of the son, also, that the separation studies were carried out among neighboring lanthanides. In this investigation, it was determined the effect that its have the complexing media: KSCN, sodium tartrate, sodium citrate, EDTA and aluminon, their pH and concentration, in the adsorption of the lanthanides in both minerals, in order to determine the chromatographic conditions for separation of the couples Nd/Pm, Dy/Ho, Gd/Tb and Yb/Lu. The work consists of five chapters, in the first one they are presented a theoretical introduction of the characteristics more important of the lanthanides, the hydroxyapatite and the fluorite; in the second, it is deepened in the ion exchange, as well as the two techniques (XRD and High Vacuum Electron Microscopy) to make the characterization of LnCI3 (Ln = Nd, Gd, Dy or Yb) synthesized. The third chapter, it describes the methodology continued in our experimental work; in the room, its are presented the obtained results of the static and dynamic method to determine the viability of separation of neighboring lanthanides; and finally, the five chapter shows the conclusions. In this study, it is concludes that the separation among neighboring lanthanides cannot be carried out in the minerals and used media; because practically these lanthanides

  2. Control of Metal Arrays Based on Heterometallics Masquerading in Heterochiral Aggregations of Chiral Clothespin-Shaped Complexes.

    Science.gov (United States)

    Naito, Masaya; Inoue, Ryo; Iida, Masayuki; Kuwajima, Yuuki; Kawamorita, Soichiro; Komiya, Naruyoshi; Naota, Takeshi

    2015-09-01

    Heterometal arrays in molecular aggregations were obtained by the spontaneous and ultrasound-induced gelation of organic liquids containing the chiral, clothespin-shaped trans-bis(salicylaldiminato) d8 transition-metal complexes 1. Heterometallic mixtures of complexes 1 a (Pd) and 1 b (Pt) underwent strict heterochiral aggregation entirely due to the organic shell structure of the clothespin shape, with no effect of the metal cores. This phenomenon provides an unprecedented means of generating highly controlled heterometallic arrangements such as alternating sequences [(+)-Pd(-)-Pt(+)-Pd(-)-Pt⋅⋅⋅] as well as a variety of single metal-enriched arrays (e.g., [(+)-Pt(-)-Pd(+)-Pd(-)-Pd(+)-Pd(-)-Pd⋅⋅⋅] and [(+)-Pd(-)-Pt(+)-Pt(-)-Pt(+)-Pt(-)-Pt⋅⋅⋅]) upon the introduction of an optically active masquerading unit with a different metal core in the heterochiral single-metal sequence. The present method can be applied to form various new aggregates with optically active Pd and Pt units, to allow 1) tuning of the gelation ultrasound sensitivity based on the different hearing abilities of the metal units; 2) aggregation-induced chirality transfer between heterometallic species; and 3) aggregation-induced chirality enhancement. A mechanistic rationale is proposed for these molecular aggregations based on the molecular structures of the units and the morphologies of the aggregates. PMID:26212577

  3. A comparative study of diastereomeric complexes formed by a prochiral substrate and three structurally analogous chiral molecules on Pt(111)

    Science.gov (United States)

    Lemay, Jean-Christian; Dong, Yi; Groves, Michael N.; Demers-Carpentier, Vincent; Goubert, Guillaume; Lafleur-Lambert, Raphaël; Boukouvalas, John; Hammer, Bjørk; McBreen, Peter H.

    2016-04-01

    A comparative study of chemisorbed bimolecular diastereomeric complexes formed by three structurally analogous chiral modifiers and a prochiral substrate on Pt(111) was performed using scanning tunneling microscopy (STM) and density functional theory (DFT) methods. The experiments determine, subject to a number of assumptions, the abundant binding configurations and whether the complexed substrate is organized into pro-S or pro-R states. The overall prochiral ratio (pr) estimated in this manner may be compared in each case to literature values for the enantiomeric ratio (er) observed in catalysis experiments. The experiments were performed using ketopantolactone as the substrate and (R)-1-(1-naphthyl)ethylamine, (R)-N-Methyl-1-(1-naphthyl)ethylamine and (R)-1-naphthyl-1,2-ethanediol as the structurally analogous chiral modifiers. The STM measurements were performed at room temperature to better mimic conditions under which the catalytic studies reported in the literature were performed. The results are discussed in terms of the stereochemical effects of subtle modifications of the structure of the chiral modifier.

  4. Redox-Triggered Helicity Inversion in Chiral Cobalt Complexes in Combination with H(+) and NO3(-) Stimuli.

    Science.gov (United States)

    Gregoliński, Janusz; Hikita, Masahiro; Sakamoto, Tatsuya; Sugimoto, Hideki; Tsukube, Hiroshi; Miyake, Hiroyuki

    2016-01-19

    Three chiral ligands with variable denticity, H2L2-H2L4, conjugated by N,N'-ethylenebis[N-methyl-(S)-alanine] and an ortho-heterosubstituted aromatic amine, were newly synthesized as analogues of previously reported H2L1. Four contracted-Λoxo cobalt(III) complexes [Co(L)](+) with left-handed helical structure of Λ4Δ2 configuration were prepared by one-electron oxidation of the corresponding contracted-Λred cobalt(II) complexes [Co(L)], which were generated from chiral ligands and Co(ClO4)2·6H2O or Co(CF3SO3)2·5.2H2O in the presence of an organic base. Although the prepared cobalt(III) complexes were very inert and kinetically stable against protonation and NO3(-) complexation, cobalt(III) reduction in the presence of CF3SO3H and/or Bu4NNO3 allowed immediate changing of their three-dimensional structures from the contracted-Λoxo form to the extended-Λ [Co(H2L)Y2](n+) (Y = solvent and/or anion, n = 0-2) form with left-handed helicity or to the extended-Δ [Co(H2L)(NO3)](+) form with right-handed helicity via N- to O-amide coordination switching. Both extended forms were contracted to the original Λoxo form by oxidation of the cobalt(II) center in the presence of an organic base. Thus, redox reactions triggered dynamic helicity inversion of the chiral cobalt complexes, via multiple molecular motions consisting of relaxation/compression, extension/contraction, and helicity inversion motions in combination with deprotonation/protonation of amide linkages and NO3(-) anion complexation. PMID:26731008

  5. Predicting Complexation Thermodynamic Parameters of β-Cyclodextrin with Chiral Guests by Using Swarm Intelligence and Support Vector Machines

    Directory of Open Access Journals (Sweden)

    Luckhana Lawtrakul

    2009-05-01

    Full Text Available The Particle Swarm Optimization (PSO and Support Vector Machines (SVMs approaches are used for predicting the thermodynamic parameters for the 1:1 inclusion complexation of chiral guests with β-cyclodextrin. A PSO is adopted for descriptor selection in the quantitative structure-property relationships (QSPR of a dataset of 74 chiral guests due to its simplicity, speed, and consistency. The modified PSO is then combined with SVMs for its good approximating properties, to generate a QSPR model with the selected features. Linear, polynomial, and Gaussian radial basis functions are used as kernels in SVMs. All models have demonstrated an impressive performance with R2 higher than 0.8.

  6. Synthesis, X-ray, and Spectroscopic Study of Dissymmetric Tetrahedral Zinc(II) Complexes from Chiral Schiff Base Naphthaldiminate Ligands with Apparent Exception to the ECD Exciton Chirality.

    Science.gov (United States)

    Enamullah, Mohammed; Makhloufi, Gamall; Ahmed, Rifat; Joy, Baitul Alif; Islam, Mohammad Ariful; Padula, Daniele; Hunter, Howard; Pescitelli, Gennaro; Janiak, Christoph

    2016-07-01

    Bidentate enantiopure Schiff base ligands, (R or S)-N-1-(Ar)ethyl-2-oxo-1-naphthaldiminate (R- or S-N^O), diastereoselectively provide Λ- or Δ-chiral-at-metal four-coordinated Zn(R- or S-N^O)2 {Ar = C6H5; Zn-1R or Zn-1S and p-C6H4OMe; Zn-2R or Zn-2S}. Two R- or S-N^O-chelate ligands coordinate to the zinc(II) in a tetrahedral mode and induce Λ- or Δ-configuration at the zinc metal center. In the solid state, the R- or S-ligand diastereoselectively gives Λ- or Δ-Zn configuration, respectively, and forms enantiopure crystals. Single crystal structure determinations show two symmetry-independent molecules (A and B) in each asymmetric unit to give Z' = 2 structures. Electronic circular dichroism (ECD) spectra show the expected mirror image relationship resulting from diastereomeric excess toward the Λ-Zn for R-ligands and Δ-Zn for S-ligands in solution. ECD spectra are well reproduced by TDDFT calculations, while the application of the exciton chirality method, in the common point-dipole approximation, predicts the wrong sign for the long-wavelength couplet. A dynamic diastereomeric equilibrium (Λ vs Δ) prevails for both R- and S-ligand-metal complexes in solution, respectively, evidenced by (1)H NMR spectroscopy. Variable temperature (1)H NMR spectra show a temperature-dependent shift of the diastereomeric equilibrium and confirm Δ-Zn configuration (for S-ligand) to be the most stable one and favored at low temperature. DSC analyses provide quantitative diastereomeric excess in the solid state for Zn-2R and Zn-2S, which is comparable to the results of solution studies. PMID:27295327

  7. Multifunctional nanomesoporous materials with upconversion (in vivo) and downconversion (in vitro) luminescence imaging based on mesoporous capping UCNPs and linking lanthanide complexes

    Science.gov (United States)

    Sun, Lining; Ge, Xiaoqian; Liu, Jinliang; Qiu, Yannan; Wei, Zuwu; Tian, Bo; Shi, Liyi

    2014-10-01

    A series of new multifunctional nanomesoporous materials based on upconversion nanophosphors NaYF4:Yb,Tm@NaGdF4 (UCNPs) and lanthanide complexes were designed and synthesized through mesoporous capping UCNPs nanophosphors and linking lanthanide (Ln) complexes. The obtained UCNPs@mSiO2-Ln(dbm)4 (Ln = Eu, Sm, Er, Nd, Yb) materials can achieve downconversion and upconversion luminescence to show multicolor emission (covering the spectral region from 450 nm to 1700 nm) under visible-light excitation and 980 nm excitation, respectively. In addition, low cytotoxicity and good biocompatibility was found as determined by methyl thiazolyl tetrazolium assay, and the nanomesoporous materials were successfully applied to cell imaging in vitro based on Eu3+ luminescence (under 405 nm excitation) and small animal imaging based on Tm3+ luminescence (under 980 nm excitation). The doped Gd3+ ion endows the nanomesoporous materials UCNPs@mSiO2-Ln(dbm)4 with effective T1 signal enhancement, which affords them as potential magnetic resonance imaging (MRI) contrast agents. Therefore, our results may provide more exciting opportunities for multimodal bioimaging and multifunctional applications.A series of new multifunctional nanomesoporous materials based on upconversion nanophosphors NaYF4:Yb,Tm@NaGdF4 (UCNPs) and lanthanide complexes were designed and synthesized through mesoporous capping UCNPs nanophosphors and linking lanthanide (Ln) complexes. The obtained UCNPs@mSiO2-Ln(dbm)4 (Ln = Eu, Sm, Er, Nd, Yb) materials can achieve downconversion and upconversion luminescence to show multicolor emission (covering the spectral region from 450 nm to 1700 nm) under visible-light excitation and 980 nm excitation, respectively. In addition, low cytotoxicity and good biocompatibility was found as determined by methyl thiazolyl tetrazolium assay, and the nanomesoporous materials were successfully applied to cell imaging in vitro based on Eu3+ luminescence (under 405 nm excitation) and small

  8. Synthesis and characterization of the complexes of lanthanide(III) chlorides and nitrates with the tetradentate schiff base diethyl(ethylenebis-β-aminocrotonate)

    International Nuclear Information System (INIS)

    The Schiff base ligand diethyl(ethylenebis-β-aminocrotonate) (LH2) reacts with lanthanide(III) chlorides and nitrates in various solvents to give solid complexes of the stoichiometries Ln(LH2)Cl3 (Ln = La - Yb), Ln(LH2)2Cl3 (Ln = La - Sm), Ln2(LH2)3Cl6 (Ln = Eu - Yb) and Ln(LH2)(NO3)3 (Ln = La - Yb). Properties, conductivity measurements, X-ray powder patterns, thermal data, magnetic moments and spectroscopic (IR, 1H-NMR, electronic diffuse reflectance and solid state emission f - f spectra) are discussed in terms of the nature of the bonding and the possible structural types. (Authors)

  9. Bioorganic modelling stereoselective reactions with chiral neutral ligand complexes as model systems for enzyme catalysis.

    Science.gov (United States)

    Kellogg, R M

    1982-01-01

    amateurs. A better understanding of non-covalent interactions may also provide the key to achieving also the twin goals of both speed and selectivity in bioorganic modelling. As far as enantioselectivity is concerned it is clear that this can be achieved fairly effectively by the use of relatively small, but appropriately placed, groups that force the substrate to complex in an enantioselective step with the ligand. In other words, the problem of enantioselectivity can be solved at the stage of complex forming, which is kinetically rapid. The p]roblem of rate enhancement lies in the mentarity with the transition state of the reaction being catalyzed. Again the achievement of this goal lies in ingenuity of design. Potential areas of applications of chiral crown ether (or cryptate) ligand systems in bioorganic modelling lie in, for example, the formation of carbon-carbon bonds, development of oxidative processes (i.e... PMID:7036410

  10. Synthetic studies on axial chiral biaryls and functional materials utilizing arene-metal complexes; aren kinzokusakutai no tokusei wo riyo shita jikufusai biariru, oyobi shinki kinosei zairyo no gosei kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Uemura, Motokazu [Osaka Prefecture University, Osaka (Japan). Faculty of Integrated Arts and Sceinces

    1999-12-16

    Axially chiral biaryls compounds are of importance not only as chiral ligands for asymmetric reactions but also as biologically active natural products, e. g., korupensamine, michellamine and vancomycin. (Arene) chromium complex exists in two enantiomeric forms based on a planar chirality. Axially chiral biaryls were stereoselectively prepared by palladium(0)-catalyzed cross-coupling of (aryl halide)Cr(CO){sub 3} complexes with arylboronic acids. This method was applied for the total synthesis of antimaralial agent korupensamine A, naphthyltetrahydro-isoquinoline alkaloid. Furthermore, chiral 1,2-diols and diamines are important compounds for asymmetric reactions. These enantionerically pure 1,2-diols and 1,2-diamines were stereoselectively prepared by pinacol coupling of planar chiral chromium complexes of benzaldehydes and benzaldimines with samarium iodide. Moreover, non-biaryl axial compounds, N,N-dialkyl 2,6-disubstituted benzamides were synthesized in enantiomerically pure form utilizing planar chiral arene chromium complex. (author)

  11. Me-3,2-HOPO Complexes of Near Infra-Red (NIR) Emitting Lanthanides: Efficient Sensitization of Yb(III) and Nd(III) in Aqueous Solution

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Evan G.; Xu, Jide; Dodani, Sheel; Jocher, Christoph; D' Aleo, Anthony; Seitz, Michael; Raymond, Kenneth

    2009-11-10

    The synthesis, X-ray structure, solution stability, and photophysical properties of several trivalent lanthanide complexes of Yb(III) and Nd(III) using both tetradentate and octadentate ligand design strategies and incorporating the 1-methyl-3-hydroxy-pyridin-2-one (Me-3,2-HOPO) chelate group are reported. Both the Yb(III) and Nd(III) complexes have emission bands in the Near Infra-Red (NIR) region, and this luminescence is retained in aqueous solution ({Phi}{sub tot}{sup Yb} {approx} 0.09-0.22%). Furthermore, the complexes demonstrate very high stability (pYb {approx} 18.8-21.9) in aqueous solution, making them good candidates for further development as probes for NIR imaging. Analysis of the low temperature (77 K) photophysical measurements for a model Gd(III) complex were used to gain an insight into the electronic structure, and were found to agree well with corresponding TD-DFT calculations at the B3LYP/6-311G{sup ++}(d,p) level of theory for a simplified model monovalent sodium complex.

  12. Synthesis and characterization of lanthanide(III) complexes with a mesogenic Schiff-base, N,N′-di-(4-decyloxysalicylidene)-2′,6′-diaminopyridine

    International Nuclear Information System (INIS)

    A mesogenic Schiff-base, N,N′-di-(4-decyloxysalicylidene)-2′,6′-diaminopyridine, H2ddsdp (abbreviated as H2L3) that exhibits nematic mesophase, was synthesized and its structure studied by elemental analysis, mass spectrometry, NMR and IR spectral techniques. The Schiff-base, H2L3, upon condensation with hydrated lanthanide(III) nitrates, yields LnIII complexes of the general composition [Ln2(L3H2)3(NO3)4](NO3)2, where Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy and Ho. Among the metal complexes, only that of HoIII is found to be mesogenic with smectic-X and nematic phases. The IR and NMR spectral data imply a bi-dentate bonding of the Schiff-base in its zwitterionic form (as L3H2) to the LnIII ions through two phenolate oxygens, rendering the overall geometry of the complexes to seven-coordinated polyhedron, possibly distorted mono-capped octahedron. - Highlights: ► Synthesis of a mesogenic Schiff's base ligand, containing three aromatic rings. ► Synthesis of LnIII complexes of the Schiff's base, H2L3. ► Structural characterization of the Schiff's base and of the LnIII complexes. ► Mesogenic studies of the Schiff's base. ► Zwitterionic coordination of the Schiff's base to LnIII ions.

  13. Luminescent lanthanide chelates and methods of use

    Energy Technology Data Exchange (ETDEWEB)

    Selvin, Paul R. (Berkeley, CA); Hearst, John (Berkeley, CA)

    1997-01-01

    The invention provides lanthanide chelates capable of intense luminescence. The celates comprise a lanthanide chelator covalently joined to a coumarin-like or quinolone-like sensitizer. Exemplary sensitzers include 2- or 4-quinolones, 2- or 4-coumarins, or derivatives thereof e.g. carbostyril 124 (7-amino-4-methyl-2-quinolone), coumarin 120 (7-amino-4-methyl-2-coumarin), coumarin 124 (7-amino-4-(trifluoromethyl)-2-coumarin), aminomethyltrimethylpsoralen, etc. The chelates form high affinity complexes with lanthanides, such as terbium or europium, through chelator groups, such as DTPA. The chelates may be coupled to a wide variety of compounds to create specific labels, probes, diagnostic and/or therapeutic reagents, etc. The chelates find particular use in resonance energy transfer between chelate-lanthanide complexes and another luminescent agent, often a fluorescent non-metal based resonance energy acceptor. The methods provide useful information about the structure, conformation, relative location and/or interactions of macromolecules.

  14. Sulfate complexation of trivalent lanthanides probed by nano-electro-spray mass spectrometry and time-resolved laser-induced fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Full text of publication follows: Sulfate complexation of lanthanides is of great interest to predict the speciation of radionuclides in natural environments. In the present work, the stability constants of sulfate complexes of trivalent lanthanide ions were investigated by two speciation techniques: nano-Electro-Spray Ionisation Mass Spectrometry (nano-ESI-MS) and Time-Resolved Laser-induced Fluorescence Spectroscopy (TRLFS). TRLFS was used to study the Eu(III) speciation in the ionic conditions 0.02-0.05 mol/l H+ (H2SO4 / HClO4) and 0.4-2.0 mol/l Na+ (Na2SO4 / NaClO4). The data were interpreted with the EuSO4+ and Eu(SO4)2- species. To calculate the effect of the ionic medium on the complexation constants, all the major ions were taken into account through several ion-pair parameters, ε, of the Specific ion Interaction Theory (SIT). Several ε values were estimated by analogy using linear correlations, while ε(Eu3+, SO42-) was fitted to experimental data, since, to date, SIT coefficients between multicharged species are not reported. The formation constants proposed here confirm some of those previously measured for Ln(III) and An(III) by various experimental techniques. The TRLFS lifetimes measured for EuSO4+ and Eu(SO4)2- were found consistent with the replacement of one H2O molecule in the first coordination sphere of Eu3+ for each added SO42- ligand, suggesting monodentate SO42- coordination. Moreover, these results and equilibrium thermodynamics do not give credit that TRLFS and other spectroscopic techniques would provide stability constants of only inner sphere complexes while they are in equilibrium with possible outer sphere complexes. Besides, numerous La(III) species were observed in a gaseous phase by nano-ESI-MS from the analysis of HNO3 / H2SO4 aqueous solutions with low ionic strength. The mass spectra were interpreted according to the expected formation of LaSO4+(aq). Its formation constant was measured and compared well with the TRLFS results

  15. Chiral Nanostructures from Helical Copolymer-Metal Complexes: Tunable Cation-π Interactions and Sergeants and Soldiers Effect.

    Science.gov (United States)

    Arias, Sandra; Bergueiro, Julián; Freire, Félix; Quiñoá, Emilio; Riguera, Ricardo

    2016-01-13

    Poly(phenylacetylene) (PPA) copolymers containing (R)- or (S)-MPA as minor chiral pendant can be forced to selectively adopt the right- o left-handed helix, in the presence of small amounts of Na(+) or Ag(+) ("Sergeants and Soldiers Effect") by addition of a donor cosolvent. The helical sense depends exclusively on the chiral monomer/donor cosolvent ratio, and this allows a perfect on/off tuning of the helicity of the copolymer. When the amount of the donor cosolvent is low, the metal ion complex is stabilized by a cation-π interaction, which is selectively cleaved when the amount of cosolvent is higher. Macroscopically chiral nanospheres and nanotubes composed by helical copolymers with P or M helical sense are also described. Our results demonstrate that it is possible to obtain the two enantiomeric helical structures (P and M helicities) and the corresponding nanospheres and nanotubes from a single helical copolymer, by controlled activation/deactivation of the Sergeant and Soldiers Effect with a donor cosolvent. PMID:26578292

  16. A mass spectrometric method for rapidly assaying the chiral selectivities of the copper(I) complexes of C2-symmetric ligands.

    Science.gov (United States)

    Davis, Mark C; Gronert, Scott

    2015-11-01

    A gas-phase method for rapidly assaying the enantioselectivity of metal-centered catalysts is presented. It relies on gas-phase equilibrium measurements in a quadrupole ion trap mass spectrometer. A group of well-established C2-symmetric bis-oxazoline copper(I) complexes was used to identify chiral probe reagents that are capable of profiling the quality of the asymmetric environment provided by the metal complex. The chiral probes were then applied to a wide variety of copper(I) bis-di-imine complexes. Complexes based on a BINAM backbone exhibited selectivities that were comparable to the bis-oxazolines. Taking advantage of the mass selectivity capabilities of the ion trap mass spectrometer, the method was also applied to an un-purified mix of copper(I) complexes derived from a combinatorial synthesis of bis-di-imine ligands. This approach holds promise as a rapid screening tool for potential chiral catalysts. PMID:26505773

  17. Synthesis and spectroscopic characterization of some lanthanide(III nitrate complexes of ethyl 2-[2-(1-acetyl-2-oxopropylazo]-4,5-dimethyl-3-thiophenecarboxyate

    Directory of Open Access Journals (Sweden)

    CHEMPAKAM JANARDHANAN ATHIRA

    2011-02-01

    Full Text Available Ethyl 2-[2-(1-acetyl-2-oxopropylazo]-4,5-dimethyl-3-thiophenecarboxyate was synthesized by coupling diazotized ethyl 2-amino-4,5-dimethylthiophene-3-carboxylate with acetylacetone. Based on various spectral studies and elemental analysis, an intramolecularly hydrogen-bonded azo-enol structural form was assigned for the ligand. This ligand is versatile in forming a series of lanthanide(III complexes, viz., lanthanum(III, cerium(III, praseodymium(III, neodymium(III, samarium(III and gadolinium(III, which were characterized through various spectral studies, elemental analysis, magnetic susceptibility measurements, molar conductance and thermal analysis. The spectral data revealed that the ligand acted as a neutral tridentate, coordinating to the metal ion through one of the azo nitrogen atoms, the ester carbonyl and the enolic oxygen of the acetylacetone moiety, without deprotonation. Molar conductance values adequately supported their non-electrolytic nature. The ligand and lanthanum(III complex were subjected to X-ray diffraction studies. In addition, the lanthanum(III complex underwent a facile transesterification reaction on refluxing with methanol for a long period. The thermal behaviour of the lanthanum(III complex was also examined

  18. Configuration-averaged 4f orbitals in ab initio calculations of low-lying crystal field levels in lanthanide(iii) complexes.

    Science.gov (United States)

    Van den Heuvel, Willem; Calvello, Simone; Soncini, Alessandro

    2016-06-21

    A successful and commonly used ab initio method for the calculation of crystal field levels and magnetic anisotropy of lanthanide complexes consists of spin-adapted state-averaged CASSCF calculations followed by state interaction with spin-orbit coupling (SI-SO). Based on two observations valid for Ln(iii) complexes, namely: (i) CASSCF 4f orbitals are expected to change very little when optimized for different states belonging to the 4f electronic configuration, (ii) due to strong spin-orbit coupling the total spin is not a good quantum number, we show here via a straightforward analysis and direct calculation that the CASSCF/SI-SO method can be simplified to a single configuration-averaged HF calculation and one complete active space CI diagonalization, including spin-orbit coupling, on determinant basis. Besides its conceptual simplicity, this approach has the advantage that all spin states of the 4f(n) configuration are automatically included in the SO coupling, thereby overcoming one of the computational limitations of the existing CASSCF/SI-SO approach. As an example, we consider three isostructural complexes [Ln(acac)3(H2O)2], Ln = Dy(3+), Ho(3+), Er(3+), and find that the proposed simplified method yields crystal field levels and magnetic g-tensors that are in very good agreement with those obtained with CASSCF/SI-SO. PMID:27231024

  19. Chiral SiO2 and Ag@SiO2 Materials Templated by Complexes Consisting of Comblike Polyethyleneimine and Tartaric Acid.

    Science.gov (United States)

    Yao, Dong-Dong; Murata, Hiroki; Tsunega, Seiji; Jin, Ren-Hua

    2015-10-26

    A facile avenue to fabricate micrometer-sized chiral (L-, D-) and meso-like (dl-) SiO2 materials with unique structures by using crystalline complexes (cPEI/tart), composed of comblike polyethyleneimine (cPEI) and L-, D-, or dl-tartaric acid, respectively, as catalytic templates is reported. Interestingly, both chiral crystalline complexes appeared as regularly left- and right-twisted bundle structures about 10 μm in length and about 5 μm in diameter, whereas the dl-form occurred as circular structures with about 10 μm diameter. Subsequently, SiO2 @cPEI/tart hybrids with high silica content (>55.0 wt %) were prepared by stirring a mixture containing tetramethoxysilane (TMOS) and the aggregates of the crystalline complexes in water. The chiral SiO2 hybrids and calcined chiral SiO2 showed very strong CD signals and a nanofiber-based morphology on their surface, whereas dl-SiO2 showed no CD activity and a nanosheet-packed disklike shape. Furthermore, metallic silver nanoparticles (Ag NPs) were encapsulated in each silica hybrid to obtain chiral (D and L forms) and meso-like (dl form) Ag@SiO2 composites. Also, the reaction between L-cysteine (Lcys) and these Ag@SiO2 composites was preliminarily investigated. Only chiral L- and D-Ag@SiO2 composites promoted the reaction between Lcys and Ag NPs to produce a molecular [Ag-Lcys]n complex with remarkable exciton chirality, whereas the reaction hardly occurred in the case of meso-like (dl-) Ag@SiO2 composite. PMID:26350940

  20. One ligand fits all: lanthanide and actinide sandwich complexes comprising the 1,4-bis(trimethylsilyl)cyclo-octa-tetra-enyl (=COT'') ligand

    International Nuclear Information System (INIS)

    The series of anionic lanthanide(III) sandwich complexes of the type [Ln(COT'')2]- (COT'' = 1,4-bis(trimethylsilyl)cyclo-octa-tetra-enyl di-anion) has been largely extended by the synthesis of eight new derivatives ranging from lanthanum to lutetium. The new compounds [Li(DME)3][Ln(COT'')2] (Ln = Y (1), La (2), Pr (3), Gd (4), Tm (6), Lu (8)) and [Li(THF)4][Ln(COT'')2] (Ln = Ho (5), Tm (7)) were prepared in good yields following a straightforward synthetic protocol which involves the treatment of LnCl3 with 2 equiv. of in situ prepared Li2COT' in either DME (=1,2-dimethoxyethane) or THF. The neutral actinide sandwich complexes An(COT'')2 (An = Th (9), U (10)) and An(COT''')2 (COT''' = 1,3,6-tris(trimethylsilyl)cyclo-octa-tetra-enyl di-anion; An = Th (11), U (12)) were synthesized in a similar manner, starting from ThCl4 or UCl4, respectively. The COT'' ligand imparts excellent solubility even in low-polar solvents as well as excellent crystallinity to all new compounds studied. All twelve new f-element sandwich complexes have been structurally authenticated by single-crystal X-ray diffraction. All are nearly perfect sandwich complexes with little deviation from the coplanar arrangement of the substituted COT'' rings. Surprisingly, all six [Li(DME)3][Ln(COT)2] complexes covering the entire range of Ln3+ ionic radii from La3+ to Lu3+ are isostructural (space group P1-bar). % Compound 10 is the first uranocene derivative for which 13C NMR data are reported. (authors)

  1. Synthesis and Characterization of Electroresponsive Materials with Applications In: Part I. Second Harmonic Generation. Part II. Organic-Lanthanide Ion Complexes for Electroluminescence and Optical Amplifiers.

    Science.gov (United States)

    Claude, Charles

    1995-01-01

    Materials for optical waveguides were developed from two different approaches, inorganic-organic composites and soft gel polymers. Inorganic-organic composites were developed from alkoxysilane and organically modified silanes based on nonlinear optical chromophores. Organically modified silanes based on N-((3^' -trialkoxysilyl)propyl)-4-nitroaniline were synthesized and sol-gelled with trimethoxysilane. After a densification process at 190^circC with a corona discharge, the second harmonic of the film was measured with a Nd:YAG laser with a fundamental wavelength of 1064nm, d_{33} = 13pm/V. The decay of the second harmonic was expressed by a stretched bi-exponential equation. The decay time (tau _2) was equal to 3374 hours, and was comparable to nonlinear optical systems based on epoxy/Disperse Orange 1. The processing temperature of the organically modified silane was limited to 200^circC due to the decomposition of the organic chromophore. Soft gel polymers were synthesized and characterized for the development of optical waveguides with dc-electrical field assisted phase-matching. Polymers based on 4-nitroaniline terminated poly(ethylene oxide-co-propylene oxide) were shown to exhibit second harmonic generation that were optically phase-matched in an electrical field. The optical signals were stable and reproducible. Siloxane polymers modified with 1-mercapto-4-nitrobenzene and 1-mercapto-4-methylsulfonylstilbene nonlinear optical chromophores were synthesized. The physical and the linear and nonlinear optical properties of the polymers were characterized. Waveguides were developed from the polymers which were optically phase -matched and had an efficiency of 8.1%. The siloxane polymers exhibited optical phase-matching in an applied electrical field and can be used with a semiconductor laser. Organic lanthanide ion complexes for electroluminescence and optical amplifiers were synthesized and characterized. The complexes were characterized for their thermal and

  2. Introduction to the structures determination methods using X-ray diffraction in monocrystals: application to some lanthanides and transition metals complexes with organic ligands

    International Nuclear Information System (INIS)

    The crystal structure of the complexes Ln (Cl O4)3.6[P O N H2 (C6 H5) 2] where Ln = Eu, La, Cu[N H2 (C H3)2 C C O2]2, Ni Br2.4[As O(C6 H5)3]. 8 H2 O (green), Ni Br2.4[As O (C6 H5)3]. 1,5 (C H3 C6 H5).H2 O (orange) and of the ligand P O N H2 (C6 H5)2 have been determined by X-ray diffraction. The complexes involving lanthanide ions refined to final R factors of R(Eu) = 0.125 and R(La) = 0.133 and the following main features were found: the crystal system is cubic; the cation is coordinated to six ligand oxygens in octahedral (Eu) and trigonal anti prismatic (La) configurations with the rate earths on positions of high symmetry (23 for Eu and 3-bar for La); the rest of the structures shows different degrees of disorder. In the light of the geometrical configuration, the occurrence of a strong band 5 DO-7 F2 in the fluorescence spectrum of the Eu complex, forbidden on symmetry grounds, is interpreted as a consequence of vibronic coupling. A splitting of the infrared νP=0 band in the La complex is attributed to the presence of P = 0 groups non-equivalently bonded to the rare earth due to the disorder of this atom. (author)

  3. Ultrasound-induced emission enhancement based on structure-dependent homo- and heterochiral aggregations of chiral binuclear platinum complexes.

    Science.gov (United States)

    Komiya, Naruyoshi; Muraoka, Takako; Iida, Masayuki; Miyanaga, Maiko; Takahashi, Koichi; Naota, Takeshi

    2011-10-12

    Instant and precise control of phosphorescent emission can be performed by ultrasound-induced gelation of organic liquids with chiral, clothespin-shaped trans-bis(salicylaldiminato)Pt(II) complexes, anti-1. Nonemissive solutions of racemic, short-linked anti-1a (n = 5) and optically pure, long-linked anti-1c (n = 7) in organic liquids are transformed immediately into stable phosphorescent gels upon brief irradiation of low-power ultrasound. Emission from the gels can be controlled by sonication time, linker length, and optical activity of the complexes. Several experimental results indicated that structure-dependent homo- and heterochiral aggregations and ultrasound-control of the aggregate morphology are key factors for emission enhancement. PMID:21894951

  4. Characterization of americium(III) and lanthanide(III) complexes in mixed solvent extraction systems containing a malonamide and a dialkyl-phosphoric acid

    International Nuclear Information System (INIS)

    In order to further reduce toxicity of nuclear waste, the French Commissariat a l'energie atomique et aux energies alternatives (CEA) is developing processes that allow separation of minor actinides from fission products. The DIAMEX (Diamide extraction) - SANEX (Selective actinide extraction) process is based on a mixture of two organic extractants: a malonamide, the N,N'-dimethyl-N,N'-dioctyl-hexyl-ethoxy-malonamide (DMDOHEMA) and a dialkyl-phosphoric acid, the di(2-ethylhexyl)phosphoric acid (HDEHP), dissolved in an alkane. The mechanisms of its extraction process are still not completely understood. Various complementary analytical techniques were used to identify and characterize americium(III) and lanthanide(III) metallic complexes formed in the organic phase after solvent extraction (UV-Visible, Infrared, NMR and Time Resolved Laser-Induced Fluorescence spectroscopy, as well as Electro-spray Ionization Mass Spectrometry). These speciation studies were performed under a variety of experimental conditions (influence of the extractants concentration, acidity of the aqueous phase..) and mixed species including the two extractants were observed. (authors)

  5. Ionization Energies of Lanthanides

    Science.gov (United States)

    Lang, Peter F.; Smith, Barry C.

    2010-01-01

    This article describes how data are used to analyze the pattern of ionization energies of the lanthanide elements. Different observed pathways of ionization between different ground states are discussed, and the effects of pairing, exchange, and orbital interactions on ionization energies of the lanthanides are evaluated. When all the above…

  6. Complexation of biological ligands with lanthanides(III) for MRI: Structure, thermodynamic and methods; Complexation des cations lanthanides trivalents par des ligands d'origine biologique pour l'IRM: Structure, thermodynamique et methodes

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, C

    2006-07-15

    New cyclic ligands derived from sugars and amino-acids form a scaffold carrying a coordination sphere of oxygen atoms suitable to complex Ln(III) ions. In spite of their rather low molecular weights, the complexes display surprisingly high relaxivity values, especially at high field. The ACX and BCX ligands, which are acidic derivatives of modified and cyclo-dextrins, form mono and bimetallic complexes with Ln(III). The LnACX and LnBCX complexes show affinities towards Ln(III) similar to those of tri-acidic ligands. In the bimetallic Lu2ACX complex, the cations are deeply embedded in the cavity of the ligand, as shown by the X-ray structure. In aqueous solution, the number of water molecules coordinated to the cation in the LnACX complex depends on the nature and concentration of the alkali ions of the supporting electrolyte, as shown by luminescence and relaxometric measurements. There is only one water molecule coordinated in the LnBCX complex, which enables us to highlight an important second sphere contribution to relaxivity. The NMR study of the RAFT peptidic ligand shows the complexation of Ln(III), with an affinity similar to those of natural ligands derived from calmodulin. The relaxometric study also shows an important second sphere contribution to relaxivity. To better understand the intricate molecular factors affecting relaxivity, we developed new relaxometric methods based on probe solutes. These methods allow us to determine the charge of the complex, weak affinity constants, trans-metallation constants, and the electronic relaxation rate. (author)

  7. Synthesis, characterization and study of some physical properties of some lanthanide complexes of salicylaldehyde oxal-dihydrazone

    International Nuclear Information System (INIS)

    Some Lanthanoid complexes of the type [Ln (L-2H).A.H2O] [Ln = Y, La, Nd, Gd, Tb, Dy, A=OAc; and L = Salicyaldehyde oxal di-hydrazone] was synthesized and characterized by various physico- chemical techniques. Dehydration study at two specific temperatures (110 deg. C and 150 deg. C) indicates the presence of water molecules only in co-ordination sphere of the metal ion. IR, electronic spectra, DTA-TG have been recorded to establish the bonding sites of the ligand. All the complexes decomposed above and not melting up to 350 deg. C. The complexes are insoluble in any common organic solvent even in DMF and DMSO. Solid state electrical conductivities at various frequencies show a semiconducting nature of the complexes. Optical band gap measurement of the complex [Dy(SODH-2H).OAc.H2O] shows that complex behaves as direct band gap material. No well-defined peaks, except broad humps were observed in X-ray diffractogram of these complexes, indicating an amorphous nature of the complexes. (author)

  8. Chiral separation of asenapine enantiomers by capillary electrophoresis and characterization of cyclodextrin complexes by NMR spectroscopy, mass spectrometry and molecular modeling.

    Science.gov (United States)

    Szabó, Zoltán-István; Tóth, Gergő; Völgyi, Gergely; Komjáti, Balázs; Hancu, Gabriel; Szente, Lajos; Sohajda, Tamás; Béni, Szabolcs; Muntean, Daniela-Lucia; Noszál, Béla

    2016-01-01

    The enantiomers of asenapine maleate (ASN), a novel antipsychotic against schizophrenia and mania with bipolar I disorder have been separated by cyclodextrin (CD) modified capillary zone electrophoresis for the first time. 15 different CDs were screened as complexing agents and chiral selectors, investigating the stability of the inclusion complexes and their enantiodiscriminating capacities. Although initially, none of the applied chiral selectors gave baseline separation, β-CD proved to be the most effective chiral selector. In order to improve resolution, an orthogonal experimental design was employed, altering the concentration of background electrolyte, organic modifier, pH, capillary temperature and applied voltage in a multivariate manner. The developed method (160 mM TRIS-acetate buffer pH 3.5, 7 mM β-CD, at 20 °C, applying 15 kV) was successful for baseline separation of ASN enantiomers (R(s)=2.40±0.04). Our method was validated according to ICH guidelines and proved to be sensitive, linear, accurate and precise for the chiral separation of ASN. Properties of the inclusion complexes, such as stoichiometry, atomic level intermolecular host-guest connections are proposed on the basis of ROESY NMR measurement, ESI-MS spectrometry and molecular modeling studies. It was found that the ASN-β-CD complex is of 1:1 composition, and either of the aromatic rings can be accommodated in the β-CD cavity. PMID:26440287

  9. Preparation and structural characterization of the intermediate complex [Er{H2C8H16N4(CH2COO)3(CH2(Ph)PO2)}(H2O)2]2Cl2.xH2O in the reaction of Er3+ and the dota-type ligand. An interesting example of two stereoforms of a lanthanide complex

    Czech Academy of Sciences Publication Activity Database

    Vojtíšek, P.; Rohovec, Jan

    2006-01-01

    Roč. 71, č. 2 (2006), s. 264-278. ISSN 0010-0765 Institutional research plan: CEZ:AV0Z30130516 Keywords : x-ray diffraction * lanthanoids * lanthanide complexes * erbium * stereochemistry Subject RIV: DD - Geochemistry Impact factor: 0.881, year: 2006

  10. Crystallographic and Spectroscopic Studies of a Host-Guest Complex Consisting of a Novel Zinc Trisporphyrinate and a Chiral Monoamine.

    Science.gov (United States)

    Han, Zhen; Li, Li; Shi, Bo; Fang, Xianshi; Wang, Yong; Hu, Chuanjiang

    2016-04-18

    We have designed and synthesized a novel zinc trisporphyrinate with a benzene tricarboxamide as the linker. In the presence of a large excess of 1-phenylethylamine, single crystals of the corresponding 1:3 host-guest complex were obtained, which provide the crystallographic structure of a host-guest complex consisting of an achiral porphyrin and a chiral monoamine. The structure reveals the 1-phenylethylamines adopt the "inside" binding mode that is stabilized by intramolecular hydrogen bonds. The NH2 of the 1-phenylethylamine is involved in both coordination and hydrogen bonding interactions. Circular dichroism (CD) and ultraviolet-visible spectra revealed that the 1:3 host-guest complex is dominant in the presence of a large excess of 1-phenylethylamine. The crystal structure shows there are two diastereomers of the 1:3 host-guest complexes. Density functional theory and TDDFT calculations suggest that one of the diastereomers is more energetically favorable, which dominates the CD signals. PMID:27023769

  11. Synthesis, characterization and spectral studies of some lanthanide complexes with p-(methoxy or chloro) phenylglyoxal thiosemicarbazone

    International Nuclear Information System (INIS)

    The present work deals with the synthesis of trivalent Pr, Nd, Sm, Eu, Gd, Tb, Dy and Yb complexes of p-methoxyphenylglyoxal thiosemicarbazone (PMPGT) and p-chlorophenylglyoxal thiosemicarbazone (PCPGT). 15 refs., 2 tabs

  12. Comparative Study of f-Element Electronic Structure across a Series of Multimetallic Actinide, Lanthanide-Actinide and Lanthanum-Actinide Complexes Possessing Redox-Active Bridging Ligands

    Energy Technology Data Exchange (ETDEWEB)

    Schelter, Eric J.; Wu, Ruilian; Veauthier, Jacqueline M.; Bauer, Eric D.; Booth, Corwin H.; Thomson, Robert K.; Graves, Christopher R.; John, Kevin D.; Scott, Brian L.; Thompson, Joe D.; Morris, David E.; Kiplinger, Jaqueline L.

    2010-02-24

    A comparative examination of the electronic interactions across a series of trimetallic actinide and mixed lanthanide-actinide and lanthanum-actinide complexes is presented. Using reduced, radical terpyridyl ligands as conduits in a bridging framework to promote intramolecular metal-metal communication, studies containing structural, electrochemical, and X-ray absorption spectroscopy are presented for (C{sub 5}Me{sub 5}){sub 2}An[-N=C(Bn)(tpy-M{l_brace}C{sub 5}Me4R{r_brace}{sub 2})]{sub 2} (where An = Th{sup IV}, U{sup IV}; Bn = CH{sub 2}C{sub 6}H{sub 5}; M = La{sup III}, Sm{sup III}, Yb{sup III}, U{sup III}; R = H, Me, Et) to reveal effects dependent on the identities of the metal ions and R-groups. The electrochemical results show differences in redox energetics at the peripheral 'M' site between complexes and significant wave splitting of the metal- and ligand-based processes indicating substantial electronic interactions between multiple redox sites across the actinide-containing bridge. Most striking is the appearance of strong electronic coupling for the trimetallic Yb{sup III}-U{sup IV}-Yb{sup III}, Sm{sup III}-U{sup IV}-Sm{sup III}, and La{sup III}-U{sup IV}-La{sup III} complexes, [8]{sup -}, [9b]{sup -} and [10b]{sup -}, respectively, whose calculated comproportionation constant K{sub c} is slightly larger than that reported for the benchmark Creutz-Taube ion. X-ray absorption studies for monometallic metallocene complexes of U{sup III}, U{sup IV}, and U{sup V} reveal small but detectable energy differences in the 'white-line' feature of the uranium L{sub III}-edges consistent with these variations in nominal oxidation state. The sum of this data provides evidence of 5f/6d-orbital participation in bonding and electronic delocalization in these multimetallic f-element complexes. An improved, high-yielding synthesis of 4{prime}-cyano-2,2{prime}:6{prime},2{double_prime}-terpyridine is also reported.

  13. Syntheses and luminescence properties of two novel lanthanide (III) perchlorate complexes with phenacyl p-tolyl sulfoxide

    International Nuclear Information System (INIS)

    Two novel solid binary complexes of rare earth perchlorate with phenacyl p-tolyl sulfoxide were synthesized and characterized by elemental analysis, molar conductivity, coordination titration analysis, IR, TG-DSC, 1HNMR and UV spectra. The results indicated that the composition of these complexes was REL7 (ClO4)3·6H2O (RE=Eu (III), Tb (III), L=C6H5COCH2SOC6H4CH3). The study on IR spectra and 1HNMR spectra revealed that phenacyl p-tolyl sulfoxide bonded with RE3+ ions by the oxygen atom in sulfinyl group. The emission spectra illustrated that both the Eu (III) and Tb (III) complexes displayed excellent luminescence in solid state, and The most intensive characteristic emission of the Eu(III) and Tb(III) complexes were 245,400 a.u. and 298,000 a.u. respectively. The slit with was 1 nm. By analysis luminescence and phosphorescence spectrum, it was found that the ligand had the advantage to absorb energy and transfer it to the Eu (III) and Tb (III) ions. The fluorescence lifetimes of the complexes were measured as well as the quantum yield of the Eu (III) complex

  14. Syntheses and luminescence properties of two novel lanthanide (III) perchlorate complexes with phenacyl p-tolyl sulfoxide

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Shu-Yan [College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China); Li, Wen-Xian, E-mail: nmglwx@163.com [College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China); Zheng, Yu-Shan [Inner Mongolia Autonomous Region Product Quality Inspection Institute, Hohhot 010070 (China); Xin, Xiao-Dong; Guo, Feng; Cao, Xiao-Fang [College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China)

    2015-06-15

    Two novel solid binary complexes of rare earth perchlorate with phenacyl p-tolyl sulfoxide were synthesized and characterized by elemental analysis, molar conductivity, coordination titration analysis, IR, TG-DSC, {sup 1}HNMR and UV spectra. The results indicated that the composition of these complexes was REL{sub 7} (ClO{sub 4}){sub 3}·6H{sub 2}O (RE=Eu (III), Tb (III), L=C{sub 6}H{sub 5}COCH{sub 2}SOC{sub 6}H{sub 4}CH{sub 3}). The study on IR spectra and {sup 1}HNMR spectra revealed that phenacyl p-tolyl sulfoxide bonded with RE{sup 3+} ions by the oxygen atom in sulfinyl group. The emission spectra illustrated that both the Eu (III) and Tb (III) complexes displayed excellent luminescence in solid state, and The most intensive characteristic emission of the Eu(III) and Tb(III) complexes were 245,400 a.u. and 298,000 a.u. respectively. The slit with was 1 nm. By analysis luminescence and phosphorescence spectrum, it was found that the ligand had the advantage to absorb energy and transfer it to the Eu (III) and Tb (III) ions. The fluorescence lifetimes of the complexes were measured as well as the quantum yield of the Eu (III) complex.

  15. Semiempirical quantum chemistry model for the lanthanides: RM1 (Recife Model 1) parameters for dysprosium, holmium and erbium.

    Science.gov (United States)

    Filho, Manoel A M; Dutra, José Diogo L; Rocha, Gerd B; Simas, Alfredo M; Freire, Ricardo O

    2014-01-01

    Complexes of dysprosium, holmium, and erbium find many applications as single-molecule magnets, as contrast agents for magnetic resonance imaging, as anti-cancer agents, in optical telecommunications, etc. Therefore, the development of tools that can be proven helpful to complex design is presently an active area of research. In this article, we advance a major improvement to the semiempirical description of lanthanide complexes: the Recife Model 1, RM1, model for the lanthanides, parameterized for the trications of Dy, Ho, and Er. By representing such lanthanide in the RM1 calculation as a three-electron atom with a set of 5 d, 6 s, and 6 p semiempirical orbitals, the accuracy of the previous sparkle models, mainly concentrated on lanthanide-oxygen and lanthanide-nitrogen distances, is extended to other types of bonds in the trication complexes' coordination polyhedra, such as lanthanide-carbon, lanthanide-chlorine, etc. This is even more important as, for example, lanthanide-carbon atom distances in the coordination polyhedra of the complexes comprise about 30% of all distances for all complexes of Dy, Ho, and Er considered. Our results indicate that the average unsigned mean error for the lanthanide-carbon distances dropped from an average of 0.30 Å, for the sparkle models, to 0.04 Å for the RM1 model for the lanthanides; for a total of 509 such distances for the set of all Dy, Ho, and Er complexes considered. A similar behavior took place for the other distances as well, such as lanthanide-chlorine, lanthanide-bromine, lanthanide, phosphorus and lanthanide-sulfur. Thus, the RM1 model for the lanthanides, being advanced in this article, broadens the range of application of semiempirical models to lanthanide complexes by including comprehensively many other types of bonds not adequately described by the previous models. PMID:24497945

  16. Lanthanide(III) Complexes of Rhodamine-DO3A Conjugates as Agents for Dual-Modal Imaging

    OpenAIRE

    Rivas, Charlotte; Stasiuk, Graeme J; Gallo, Juan; Minuzzi, Florencia; Rutter, Guy A.; Long, Nicholas J

    2013-01-01

    Two novel dual-modal MRI/optical probes based on a rhodamine–DO3A conjugate have been prepared. The bis(aqua)gadolinium(III) complex Gd.L1 and mono(aqua)gadolinium(III) complex Gd.L2 behave as dual-modal imaging probes (r 1 = 8.5 and 3.8 mM–1 s–1 for Gd.L1 and Gd.L2, respectively; λex = 560 nm and λem = 580 nm for both complexes). The rhodamine fragment is pH-sensitive, and upon lowering of the pH, an increase in fluorescence intensity is observed as the spirolactam ring opens to give the hig...

  17. Influence of bulky N-substituents on the formation of lanthanide triple helical complexes with a ligand derived from bis(benzimidazole)pyridine: structural and thermodynamic evidence.

    Science.gov (United States)

    Muller, G; Bünzli, J C; Schenk, K J; Piguet, C; Hopfgartner, G

    2001-06-01

    The planar aromatic tridentate ligand 2,6-bis(1-S-neopentylbenzimidazol-2-yl)pyridine (L(11)) reacts with Ln(III) (Ln = La-Lu) in acetonitrile to give the successive complexes [Ln(L(11))(n)](3+) (n = 1-3). However, stability constants determined by spectrophotometry and NMR titrations show that formation of the tris complexes is not favored, log K(3) being around 1 for La(III) and Eu(III), while no such species could be evidenced for the smaller Lu(III) ion. The X-ray structures of L(11) (monoclinic, P2(1), a = 13.4850(12) A, b = 12.0243(11) A, c = 16.4239(14) A, beta = 103.747(7) degrees ), [La(ClO(4))(2)(L(11))(2)](3)[La(ClO(4))(2)(H(2)O)(L(11))(2)](ClO(4))(4).15MeCN (1a, monoclinic, P2(1), a = 21.765(4) A, b = 30.769(6) A, c = 21.541(5) A, beta = 116.01(3) degrees ), and [Eu(L(11))(3)](ClO(4))(3).4.28MeCN (5a, monoclinic, P1, a = 14.166(3) A, b = 19.212(4) A, c = 21.099(4) A, alpha = 108.91(3) degrees, beta = 98.22(3) degrees, gamma = 108.40(3) degrees ) have been solved. In 1a, two different types of complex cations are evidenced, both containing 10-coordinate La(III) ions. In the first type, both perchlorate anions are bidentate, while in the second type, one perchlorate is monodentate, the 10th coordination position being occupied by a water molecule. In 5a the three ligands are not equivalent. Ligands A and B are wrapped in a helical way and are mirror images of each other, while ligand C lies almost perpendicular to the two other ones. This stems from the steric hindrance generated by the bulky neopentyl groups with the consecutive loss of any stabilizing interstrand pi-stacking interactions. This explains the low stability of the tris complexes and the difficulty of isolating them and points to the importance of the steric factors in the design of self-assembled triple helical lanthanide-containing functional edifices [Ln(L(i))(3)](3+). PMID:11375674

  18. Determination of crystal structures by x-ray diffraction: applications to a lanthanide complex and a natural organic compound

    International Nuclear Information System (INIS)

    The study fir determining crystal structures of the Ho (ReO sub(4)) sub(3) 4 TDTD 3 H sub(2) O complex and the natural organic compound C sub(14) H sub(16) O sub(6) by X-ray diffraction are presented. The experimental equipments are described in details. (M.C.K.)

  19. Simulations of electrolytes at the liquid-liquid interface and of lanthanide cations complexes in gas phase; Simulations d'electrolytes a l'interface liquide/liquide et de complexes de cations lanthanides en phase gazeuse

    Energy Technology Data Exchange (ETDEWEB)

    Berny, F

    2000-07-01

    Two processes related to liquid/liquid extraction of ions by extractant molecules were studied: the ion approach at the interface and the ion complexation by ligands. In the first part, the behaviour of salts at the chloroform/water interface was simulated by molecular dynamics. The aim was to understand the way these salts ions approach the interface in order to be extracted. Some ions are repelled by the interface (K{sup +}, Cl{sup -}, UO{sub 2}{sup 2+}, Na{sup +}, NO{sub 3}{sup -}) whereas others adsorb (amphiphilic molecules and also ClO{sub 4}{sup -}, SCN{sup -}, guanidinium Gu{sup +} and picrate Pic{sup -}). The surface-active counter-ions make the ion approach at the interface easier. In a perfectly homogeneous mixture of the two solvents (water and chloroform) de-mixing, the ions seem to influence the phases separation rate. Nitric acid which is known to favour liquid/liquid extraction reveals strong adsorption at the interface in its neutral form and a smaller one in its ionic form (H{sub 3}O{sup +}/NO{sub 3}{sup -}). HNO{sub 3} and H{sub 3}O{sup +} display particular orientations at the interface: hydrogen atoms are pointing in the direction of the water slab. The nature of the organic phase can also influence the ion approach at the interface. For example, Gu{sup +} and Pic{sup -} adsorb much less at the supercritical CO{sub 2}/water interface than at the chloroform/water interface. In the second part, complexes of La{sup 3+}, Eu{sup 3+} and Yb{sup 3+} with ligands such as amide, urea, thio-amide, thiourea were studied by quantum mechanics. Our calculations show that cation-ligand interactions depend on the nature of substituents on ligands, on the presence of counter-ions or on the number of ligands in the complex. Sulfur compounds seem to less interact with cations than oxygen compounds. Ureas interact as much as amides and are potentially good ligands. (author)

  20. Trivalent actinide and lanthanide complexation of 5,6-dialkyl-2,6-bis(1,2,4-triazin-3-yl)pyridine (RBTP; R = H, Me, Et) derivatives: a combined experimental and first-principles study.

    Science.gov (United States)

    Bhattacharyya, Arunasis; Kim, Eunja; Weck, Philippe F; Forster, Paul M; Czerwinski, Kenneth R

    2013-01-18

    Complexations of lanthanide ions with 5,6-dialkyl-2,6-bis(1,2,4-triazin-3-yl)pyridine [RBTP; R = H (HBTP), methyl (MeBTP), ethyl (EtBTP)] derivatives have been studied in the acetonitrile medium by electrospray ionization mass spectrometry, time-resolved laser-induced fluorescence spectroscopy, and UV-vis spectrophotometric titration. These studies were carried out in the absence and presence of a nitrate ion in order to understand the effect of the nitrate ion on their complexation behavior, particularly in the poor solvating acetonitrile medium where strong nitrate complexation of hard lanthanide ions is expected. Consistent results from all three techniques undoubtedly show the formation of lower stoichiometric complexes in the presence of excess nitrate ion. This kind of nitrate ion effect on the speciation of Ln(3+) complexes of RBTP ligands has not so far been reported in the literature. Different Am(3+) and Ln(3+) complexes were observed with RBTP ligands in the presence of 0.01 M tetramethylammonium nitrate, and their stability constant values are determined using UV-vis spectrophotometric titrations. The formation of higher stoichiometric complexes and higher stability constants for Am(3+) compared to Ln(3+) ions indicates the selectivity of these classes of ligands. A single-crystal X-ray diffraction (XRD) study of europium(III) complexes shows the formation of a dimeric complex with HBTP and a monomeric complex with EtBTP, whereas MeBTP forms both the dimeric and monomeric complexes. Density functional theory calculations confirm the findings from single-crystal XRD and also predict the structures of Eu(3+) and Am(3+) complexes observed experimentally. PMID:23270453

  1. Recovery of lanthanides

    International Nuclear Information System (INIS)

    This paper discusses a method for recovering a lanthanide and thorium from a material containing a fluorine compound and the lanthanide and thorium. It comprises a. obtaining the material from a roasted, acid-leached bastnasite ore; b. forming a mixture of the material with at least about ten weight percent of silica; c. contacting the mixture with sulfuric acid; d. heating the mixture and sulfuric acid to a temperature of at least about 150 degrees C for at least about 3 hours to cause most of the fluorine to be released as a volatile material containing silicon and fluorine; e. contacting the reacted mixture with an aqueous medium consisting essentially of water to solubilize the lanthanide and thorium while leaving an insoluble residue; and f. separating the aqueous solution of the lanthanide and thorium from the insoluble residue

  2. A [Cyclentetrakis(methylene)]tetrakis[2-hydroxybenzamide]Ligand That Complexes and Sensitizes Lanthanide(III) Ions

    Energy Technology Data Exchange (ETDEWEB)

    D' Aleo, Anthony; Xu, Jide; Do, King; Muller, Gilles; Raymond, Kenneth N.

    2009-04-30

    The synthesis of a cyclen derivative containing four isophthalamide groups (L{sup 1}) is described. The spectroscopic properties of the Ln(III) complexes of L{sup 1} (Ln = Gd, Tb, Yb, Eu) reveal changes of the UV/visible absorption, circular dichroism absorption, luminescence and circularly polarized luminescence properties. It is shown that at least two metal complex species are present in solution, whose relative amounts are pH dependent. When at pH > 8.0, an intense long lived emission is observed (for [L{sup 1}Tb] and [L{sup 1}Yb]) while at pH < 8.0, a weaker, shorter-lived species predominates. Unconventional Ln(III) emitters (Pr, Nd, Sm, Dy and Tm) were sensitized in basic solution, both in the visible and in the near infra-red, to measure the emission of these ions.

  3. Application of the oscillator strength of 'hypersensitive' transitions to the investigation of complex equilibria of lanthanide ions

    International Nuclear Information System (INIS)

    Stability constants and thermodynamic parameters of Nd3+, Ho3+ and Er3+ complexes with acetates, propionates, glycolates, lactates and α-hydroxyisobutyrates were determined by a spectroscopic method based upon the measurements of the variation of oscillator strengths of 'hypersensitive' 4f-4f-transitions. The sets of βsub (n) values at 210C are in a good agreement with those found potentiometrically. The stability constants of the complexes evaluated at 5 different temperatures were used for the calculation of ΔG, ΔH, ΔS values. The evaluated thermodynamic parameters are in a satisfactory agreement with those found calorimetrically. The thermodynamic parameters calculated from two independent 'hypersensitive' transitions of the Er3+ ion are also consistent. (author)

  4. Lanthanide(III) Complexes of DOTA-Glycoconjugates: A Potential New Class of Lectin-Mediated Medical Imaging Agents

    OpenAIRE

    André, João P.; Geraldes, Carlos F. G. C.; Martins, José A.; Merbach, André E.; Prata, Maria I. M.; Santos, Ana C; Lima, João J. P. de; Tóth, Éva

    2004-01-01

    The synthesis and characterization of a new class of DOTA (1,4,7,10-tetrakis(carboxymethyl)-1,4,7,10-tetraazacyclododecane) monoamide-linked glycoconjugates (glucose, lactose and galactose) of different valencies (mono, di and tetra) and their Sm(III), Eu(III) and Gd(III) complexes are reported. The proton NMR spectrum of Eu(III)-DOTALac(III) shows the predominance of a single structural isomer of square antiprismatic geometry of the DOTA chelating moiety and fast ...

  5. Potentiometric and polarographic studies on some aza styrene Schiff bases and their complexes with some lanthanide ions

    International Nuclear Information System (INIS)

    Potentiometric and polarographic studies have been carried out on some Schiff bases obtained by the condensation of o-hydroxybenylamine with salicyladehyde and some of its derivatives as well as their complexes have been determined potentiometrically by Bjerrum-Calvin method (Irving and Rossotti modification) and polarographically by Lingane method. Also the polarographic reduction of the Schiff bases was investigated in ethanolic-buffered solutions. A mechanism of the electrode reaction is proposed and discussed. (author). 10 refs., 2 figs., 3 tabs

  6. Kinetics of fast ligand exchange in excited lanthanide complexes with anions of salicylic and 5-sulfosalisylic acids

    International Nuclear Information System (INIS)

    The luminescent-kinetic spectroscopic method with a flash selective photoexcitation has been used for studying the reaction of ligand substitution with solvent molecules in complexes of electron-excited ions Tb3+(5D4) and Dysup(3+)(sup(4)Fsub(9/2) with anions of salicylic and 5-sulphosalicylic acids in water and methanol. The acidic-catalytic mechanism of this reaction in water has been established, the limiting stage of complex dissociation being the stage of proton addition to the -COO- group of the ligand proceeding at a rate of 1x1010 mol-1s-1 and 0.77x1010 mol-1xs-1 for complexes of Tb3+(5D4) in H2O and D2O. It has been shown that in an aqueous medium anions of salicylic and 5-sulphosalicylic acids behave with respect to r.e.e. ions as bidentate ligands coordinating these ions with the oxygen of the -COO- group and oxygroup whereas in methanol an additional coordination with oxygen of the oxygroup is absent

  7. Synthesis characterization and toxicity of lanthanide complexes with schiff bases derived from S-benzoyl dithiocarbazate and aldehydes

    International Nuclear Information System (INIS)

    New O:N:S and N:S donor ligands namely, S-benzoyl-N-(o-hydroxybenzaldehyde) dithiocarbazate, S-benzoyl-N-(N,N-dimethylaminobenzaldehyde ) dithiocarbazate, S-benzoyl-N(N-thiophene-2-aldehyde) dithiocarbazate and their complexes with La(III), Ce(III), Pr(III), Nd(III), Sm(III), Gd(III), Tb(III), Dy(III), Ho(III), Er(III), Yb(III), and Lu(III) have been synthesized and characterized on the basis of elemental analysis, IR, NMR and electronic spectroscopy. The nephelauxetic effect(1-βoverlined), bonding parameter, βoverlined, bsup(1/2) and Sinha covalency parameter δ, have been calculated. Their positive values indicate covalent nature of metal-ligand bond which is also supported by their molar conductances measured in nitrobenzene. Magnetic moment values exhibit paramagnetic nature of the complexes. Log K,ΔG, ΔH and ΔS values have also been ca lculated. Toxicity of the compounds has been evaluated against cockroaches and fungi(Aspergillus flavus and A. niger). The LD50 and % inhibition values demonstrate greater efficacy of the complexes than that of the free bases. (author). 4 tabs., 12 refs

  8. Synthesis, spectral properties and DNA binding and nuclease activity of lanthanide (III) complexes of 2-benzoylpyridine benzhydrazone: X-ray crystal structure, Hirshfeld studies and nitrate- interactions of cerium(III) complex

    Indian Academy of Sciences (India)

    Karreddula Raja; Akkili Suseelamma; Katreddi Hussain Reddy

    2016-01-01

    The lanthanide(III) complexes of general formula of [Ln(BPBH)2(NO3)3] (where, Ln = La, Ce, Pr, Nd and BPBH = 2-benzoylpyridine benzhydrazone) have been synthesized and characterized by elemental analysis, molar conductance, spectroscopic (UV, IR), electrochemical and single crystal X-ray diffraction studies. The coordination mode of the ligand and the geometry of [Ce(BPBH)2(NO3)3] are confirmed by single crystal X-ray studies. The crystals are monoclinic with C2/c crystallographic symmetry. The central metal is 12 coordinated and the coordination polyhedron around the cerium atom can be described as a distorted icosahedron. The existence of nitrate. . . and CH. . . stacking interactions in the [Ce(BPBH)2(NO3)3] leads to a supramolecular arrangement in its network. The binding properties of these complexes with calf-thymus DNA have been investigated by viscosity measurements. The complexes show more nuclease activity in the presences of H2O2.

  9. Aqueous complexes of lanthanides(III) and actinides(III) with the carbonate and sulphate ions. Thermodynamic study by time-resolved laser-induced fluorescence spectroscopy and electro-spray-ionisation mass spectrometry; Complexes aqueux de lanthanides (3) et actinides (3) avec les ions carbonate et sulfate. Etude thermodynamique par spectrofluorimetrie laser resolue en temps et spectrometrie de masse a ionisation electrospray

    Energy Technology Data Exchange (ETDEWEB)

    Vercouter, Th

    2005-03-15

    The prediction of the environmental impact of a possible geological disposal of radioactive wastes is supported by the thermodynamic modelling of the radionuclides behaviour in the groundwater. In this framework, the analogy between lanthanides and actinides(III) is confirmed by a critical analysis of the literature and the comparison with experimental results obtained here. The limiting complex, Eu(CO{sub 3}){sub 3}{sup 3-}, is identified by solubility measurements in Na{sub 2}CO{sub 3} solutions. Then the formation constants of the complexes Eu(CO{sub 3}){sub i}{sup 3-2i} (i=1-3) and Eu(SO{sub 4}){sub i}{sup 3-2i} (i=1-2) are measured by TRLFS. The formation of aqueous LaSO{sub 4}{sup +} is studied by ESI-MS and is in good agreement with the expected speciation. The enthalpy and entropy of the reaction Cm(CO{sub 3}){sub 2}{sup -} + CO{sub 3}{sup 2-} {r_reversible} Cm(CO{sub 3}){sub 3}{sup 3-} are deduced from TRLFS measurements of the equilibrium constant between 10 and 70 C. The ionic strength effect is calculated using the SIT formula. (author)

  10. Curvature of the Lanthanide Contraction: An Explanation

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, Kenneth; Wellman, Daniel; Sgarlata, Carmelo; Hill, Aru

    2009-12-21

    A number of studies have shown that for isostructural series of the lanthanides (elements La through Lu), a plot of equivalent metal-ligand bond lengths versus atomic number differs significantly from linearity and can be better fit as a quadratic equation. However, for hydrogen type wave functions, it is the inverse of the average distance of the electron from the nucleus (an estimate of size) that varies linearly with effective nuclear charge. This generates an apparent quadratic dependence of radius with atomic number. Plotting the inverse of lanthanide ion radii (the observed distance minus the ligand size) as a function of effective nuclear charge gives very good linear fits for a variety of lanthanide complexes and materials. Parameters obtained from this fit are in excellent agreement with the calculated Slater shielding constant, k.

  11. New reagents for actinide-lanthanide group separations

    International Nuclear Information System (INIS)

    Organic extractants which possess nitrogen or sulfur donor atoms preferentially complex the trivalent actinide. They are potential reagents for actinide lanthanide group separations, which can be performed at low pH without the addition of inorganic salts

  12. Simulations of electrolytes at the liquid-liquid interface and of lanthanide cations complexes in gas phase

    International Nuclear Information System (INIS)

    Two processes related to liquid/liquid extraction of ions by extractant molecules were studied: the ion approach at the interface and the ion complexation by ligands. In the first part, the behaviour of salts at the chloroform/water interface was simulated by molecular dynamics. The aim was to understand the way these salts ions approach the interface in order to be extracted. Some ions are repelled by the interface (K+, Cl-, UO22+, Na+, NO3-) whereas others adsorb (amphiphilic molecules and also ClO4-, SCN-, guanidinium Gu+ and picrate Pic-). The surface-active counter-ions make the ion approach at the interface easier. In a perfectly homogeneous mixture of the two solvents (water and chloroform) de-mixing, the ions seem to influence the phases separation rate. Nitric acid which is known to favour liquid/liquid extraction reveals strong adsorption at the interface in its neutral form and a smaller one in its ionic form (H3O+/NO3-). HNO3 and H3O+ display particular orientations at the interface: hydrogen atoms are pointing in the direction of the water slab. The nature of the organic phase can also influence the ion approach at the interface. For example, Gu+ and Pic- adsorb much less at the supercritical CO2/water interface than at the chloroform/water interface. In the second part, complexes of La3+, Eu3+ and Yb3+ with ligands such as amide, urea, thio-amide, thiourea were studied by quantum mechanics. Our calculations show that cation-ligand interactions depend on the nature of substituents on ligands, on the presence of counter-ions or on the number of ligands in the complex. Sulfur compounds seem to less interact with cations than oxygen compounds. Ureas interact as much as amides and are potentially good ligands. (author)

  13. Influence of metal loading and humic acid functional groups on the complexation behavior of trivalent lanthanides analyzed by CE-ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Kautenburger, Ralf, E-mail: r.kautenburger@mx.uni-saarland.de [Institute of Inorganic Solid State Chemistry, Saarland University, Campus Dudweiler, Am Markt Zeile 3-5, D-66125 Saarbrücken (Germany); Hein, Christina; Sander, Jonas M. [Institute of Inorganic Solid State Chemistry, Saarland University, Campus Dudweiler, Am Markt Zeile 3-5, D-66125 Saarbrücken (Germany); Beck, Horst P. [Institute of Inorganic and Analytical Chemistry and Radiochemistry, Saarland University, Campus Dudweiler, Am Markt Zeile 5, D-66125 Saarbrücken (Germany)

    2014-03-01

    Highlights: • Free and complexed HA-Ln species are separated by CE-ICP-MS. • Weaker and stronger HA-binding sites for Ln-complexation can be detected. • Complexation by original and modified humic acid (HA) with blocked phenolic hydroxyl- and carboxyl-groups is compared. • Stronger HA-binding sites for Ln³⁺ can be assumed as chelating complexes. • Chelates consist of trivalent Ln and a combination of both OH- and COOH-groups. Abstract: The complexation behavior of Aldrich humic acid (AHA) and a modified humic acid (AHA-PB) with blocked phenolic hydroxyl groups for trivalent lanthanides (Ln) is compared, and their influence on the mobility of Ln(III) in an aquifer is analyzed. As speciation technique, capillary electrophoresis (CE) was hyphenated with inductively coupled plasma mass spectrometry (ICP-MS). For metal loading experiments 25 mg L⁻¹ of AHA and different concentrations (c Ln(Eu+Gd)} = 100–6000 μg L⁻¹) of Eu(III) and Gd(III) in 10 mM NaClO₄ at pH 5 were applied. By CE-ICP-MS, three Ln-fractions, assumed to be uncomplexed, weakly and strongly AHA-complexed metal can be detected. For the used Ln/AHA-ratios conservative complex stability constants log βLnAHA decrease from 6.33 (100 μg L⁻¹ Ln³⁺) to 4.31 (6000 μg L⁻¹ Ln³⁺) with growing Ln-content. In order to verify the postulated weaker and stronger humic acid binding sites for trivalent Eu and Gd, a modified AHA with blocked functional groups was used. For these experiments 500 μg L⁻¹ Eu and 25 mg L⁻¹ AHA and AHA-PB in 10 mM NaClO₄ at pH-values ranging from 3 to 10 have been applied. With AHA-PB, where 84% of the phenolic OH-groups and 40% of the COOH-groups were blocked, Eu complexation was significantly lower, especially at the strong binding sites. The log β-values decrease from 6.11 (pH 10) to 5.61 at pH 3 (AHA) and for AHA-PB from 6.01 (pH 7) to 3.94 at pH 3. As a potential consequence, particularly humic acids with a high amount of

  14. Chirality of weakly bound complexes: The potential energy surfaces for the hydrogen-peroxide−noble-gas interactions

    Energy Technology Data Exchange (ETDEWEB)

    Roncaratti, L. F., E-mail: lz@fis.unb.br; Leal, L. A.; Silva, G. M. de [Instituto de Física, Universidade de Brasília, 70910 Brasília (Brazil); Pirani, F. [Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, 06123 Perugia (Italy); Aquilanti, V. [Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, 06123 Perugia (Italy); Instituto de Física, Universidade Federal da Bahia, 40210 Salvador (Brazil); Gargano, R. [Instituto de Física, Universidade de Brasília, 70910 Brasília (Brazil); Departments of Chemistry and Physics, University of Florida, Quantum Theory Project, Gainesville, Florida 32611 (United States)

    2014-10-07

    We consider the analytical representation of the potential energy surfaces of relevance for the intermolecular dynamics of weakly bound complexes of chiral molecules. In this paper we study the H{sub 2}O{sub 2}−Ng (Ng=He, Ne, Ar, Kr, and Xe) systems providing the radial and the angular dependence of the potential energy surface on the relative position of the Ng atom. We accomplish this by introducing an analytical representation which is able to fit the ab initio energies of these complexes in a wide range of geometries. Our analysis sheds light on the role that the enantiomeric forms and the symmetry of the H{sub 2}O{sub 2} molecule play on the resulting barriers and equilibrium geometries. The proposed theoretical framework is useful to study the dynamics of the H{sub 2}O{sub 2} molecule, or other systems involving O–O and S–S bonds, interacting by non-covalent forces with atoms or molecules and to understand how the relative orientation of the O–H bonds changes along collisional events that may lead to a hydrogen bond formation or even to selectivity in chemical reactions.

  15. Preparation, crystal structure and luminescent properties of the (6,3) type network supramolecular lanthanide picrate complexes with 2,2'-[(1,2-naphthalene)bis(oxy)]bis[N-(phenylmethyl)]acetamide

    International Nuclear Information System (INIS)

    Solid complexes of lanthanide picrates with a new podand-type ligand, 2,2'-[(1,2-naphthalene)bis(oxy)]bis[N-(phenylmethyl)]acetamide (L) have been prepared and characterized by elemental analysis, conductivity measurements, IR and electronic spectroscopies. The crystal and molecular structures of the coordination polymer {[Eu2L3(Pic)6].(CHCl3)3.(H2O)0.5}n have been determined by single-crystal X-ray diffraction, and the structure displays a two-dimensional honeycomb-like framework in the ab plane, which can be regarded as a (6,3) topological network with europium atoms acting as 'three-connected' centers. Furthermore, the coordination layers are linked by the intermolecular hydrogen bonds to form a three-dimensional (3-D) netlike supermolecule. Under excitation, Eu complex exhibited characteristic emissions. The lowest triplet state energy level of the ligand indicates that the triplet state energy level of the ligand matches better to the resonance level of Eu(III) than Tb(III) ion. - Graphical abstract: The (6,3) type network supramolecular luminescent lanthanide picrate complexes {Ln2L3(Pic)6}n (L=2,2'-[(1,2-naphthalene)bis(oxy)]bis[N-(phenylmethyl)]acetamide) displaying a two-dimensional honeycomb-like framework have been designed and prepared.

  16. Structural and thermodynamic study of rare earth(III) complexation by poly-hydroxylated carboxylic acids: synthesis of new extractants and outlook for the extraction of these cations; Etude structurale et thermodynamique de la complexation de lanthanides (III) par des acides carboxyliques polyhydroxyles: synthese de nouveaux extractants et perspectives pour l'extraction de ces cations

    Energy Technology Data Exchange (ETDEWEB)

    Aury, S

    2002-12-15

    The aim of this work is: to improve the knowledge on the binding sites of the poly-hydroxylated carboxylic acids with the trivalent lanthanide(III) ions by comparing them to gluconic acid (previously studied) and to molecules with different configuration and with a variable number of OH functions (threonic acid, glyceric acid, 2-hydroxy-butanoic acid, 3-hydroxy-butanoic acid). To find the best complexing agent among different acids (aldonic acids, aldaric acids, di-hydroxybenzoic acids) (determination of the set of complexes and their stability constants by potentiometry, NMR and UV-Visible spectroscopy). To synthesize hydrophobic monoamides from one lactone form of saccharic acid, to study their complexing power and their capacity to extract the trivalent lanthanide(III) ions. (author)

  17. Architectures moléculaire et supramoléculaires à base de Lanthanides Luminescents

    OpenAIRE

    Bozoklu, Gulay

    2011-01-01

    The construction of preprogrammed, sophisticated and nanoscopic polymetallic lanthanide complexes for the development of luminescent materials that possess new or improved photophysical properties (dual emission, intermetallic energy transfer, etc.) is one of the hot topics in the lanthanide supramolecular chemistry. Understanding, controlling and programming self assembly of lanthanide complexes is a key challenge due to the difficulty in controlling the coordination environment of these ion...

  18. Fabrication of a Complex Two-Dimensional Adenine-Perylene-3,4,9, 10-tetracarboxylic Dianhydride Chiral Nanoarchitecture through Molecular Self-Assembly

    OpenAIRE

    Sun, Xiaonan; Mura, Manuela; Jonkman, Harry T.; Kantorovich, Lev N.; Silly, Fabien

    2012-01-01

    The two-dimensional self-assembly of a nonsyrnmetric adenine DNA base mixed with symmetric perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) molecules is investigated using scanning tunneling microscopy (STM). We experimentally observe that these two building blocks form a complex close-packed chiral supramolecular network on Au(111). The unit cell of the adenine PTCDA nanoarchitecture is composed of 14 molecules. The high stability of this structure relies on PTCDA-PTCDA and PTCDA-adenin...

  19. Chiral phenoxyimino-amido aluminum complexes for the asymmetric cyanation of aldehydes.

    Science.gov (United States)

    Ternel, J; Agbossou-Niedercorn, F; Gauvin, R M

    2014-03-21

    The reactivity of triethylaluminum towards salicylaldimine sulfonamides was probed, affording well-defined complexes through consecutive protonolysis of two Al-C bonds by the proligand. These complexes, when combined with an achiral anilinic N-oxide, catalyze the asymmetric addition of trimethylsilylcyanide to a wide range of aldehydes, with good activity and enantioselectivity (up to 91% ee). Insertion of the benzaldehyde substrate into the Al-N amido bond was observed, bringing elements for discussion around the nature of the actual active species. PMID:24434893

  20. From Antenna to Assay: Lessons Learned in Lanthanide Luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Evan; Samuel, Amanda; Raymond, Kenneth

    2008-09-25

    Ligand-sensitized luminescent lanthanide(III) complexes are of considerable current interest due to their unique photophysical properties (micro- to millisecond lifetimes, characteristic and narrow emission bands, and large Stokes shifts), which make them well suited to serve as labels in fluorescence-based bioassays. The long-lived Ln(III) emission can be temporally resolved from scattered light and background fluorescence, resulting in vastly enhanced measurement sensitivity. One of the challenges in this field is the design of sensitizing ligands that provide highly emissive Ln(III) complexes that also possess sufficient stability and aqueous solubility required for practical applications. In this account we give an overview of some of the general properties of the trivalent lanthanides and follow with a summary of advances made in our laboratory in the development of highly luminescent Tb(III) and Eu(III) complexes for applications in biotechnology. A focus of our research has been the optimization of these compounds as potential commercial agents for use in Homogeneous Time Resolved Fluorescence (HTRF) technology, the requirements and current use of which will be briefly discussed. Our approach involves developing high-stability octadentate Tb(III) and Eu(III) complexes that rely on all-oxygen donor atoms as well as using multi-chromophore chelates to increase molar absorptivity compared to earlier examples that utilize a single pendant antenna chromophore. We have found that ligands based on 2-hydroxyisophthalamide (IAM) provide exceptionally emissive Tb(III) complexes with quantum yield values up to ca. 60%. Solution thermodynamic studies have indicated that these complexes are stable at the nanomolar concentrations required for commercial assays. Through synthetic modification of the IAM-chromophore, in conjunction with time-dependent density functional theory (TD-DFT) calculations, we have developed a method to predict absorption and emission properties of

  1. Effect of complexation with lanthanide metal ions on the photochromism of (1,3,3-trimethyl- 5 ′ -hydroxy- 6 ′ -formyl- indoline-spiro2,2 ′ -[2h]chromene in different media

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Complexation of lanthanide ions {Ln(III ions [Tb(III, Eu(III, or Sm(III]} with the spiropyran-derived merocyanine obtained in dark and under steady irradiation of indoline spiropyran (1,3,3-trimethyl- 5 ′ -hydroxy- 6 ′ -formyl-indoline-spiro-2,2 ′ -[2H]chromene induces a noticeable hypsochromic shift of about 10–110 nm of its visible absorption band concomitant with hypochromic effect and influences its thermal bleaching in the dark. The effect of lanthanide ions and medium on photochromic, spectral-and-kinetic, and luminescence properties of the spiropyran and its complexes in solution and polymer matrix of polymethylmethacrylate (PMMA is studied. Efficient energy transfer from the spiropyran moiety results in efficient typical luminescence from the Ln(III ion that becomes more pronounced in polar nonalcoholic solvents and PMMA solid matrix. Moreover, luminescence mappings for pattern recognition analysis have been obtained from which the nature of the solvent and/or the ligand is clearly identified.

  2. Detection of Molecular Chirality by Induced Resonance Raman Optical Activity in Europium Complexes

    Czech Academy of Sciences Publication Activity Database

    Yamamoto, Shigeki; Bouř, Petr

    2012-01-01

    Roč. 51, č. 44 (2012), s. 11058-11061. ISSN 1433-7851 R&D Projects: GA MŠk(CZ) LH11033; GA ČR GAP208/11/0105 Institutional support: RVO:61388963 Keywords : europium * complexes * raman optical activity * resonance Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 13.734, year: 2012

  3. Chiral Electronics

    OpenAIRE

    Kharzeev, Dmitri E.; Yee, Ho-Ung

    2012-01-01

    We consider the properties of electric circuits involving Weyl semimetals. The existence of the anomaly-induced chiral magnetic current in a Weyl semimetal subjected to magnetic field causes an interesting and unusual behavior of such circuits. We consider two explicit examples: i) a circuit involving the "chiral battery" and ii) a circuit that can be used as a "quantum amplifier" of magnetic field. The unique properties of these circuits stem from the chiral anomaly and may be utilized for c...

  4. Rare earth(III) complexes for the development of new magnetic and luminescent probes; Complexes de lanthanides(III) pour le developpement de nouvelles sondes magnetiques et luminescentes

    Energy Technology Data Exchange (ETDEWEB)

    Nonat, A

    2007-10-15

    The simultaneous optimisation of the molecular parameters determining the relaxivity (number of coordinated water molecules, water-exchange, rotation dynamics of the whole complex, electronic relaxation, Gd(III)-proton distance) is essential to prepare efficient contrast agents. The aim of this work is on the one hand to design and study complexes with a high number of bound water molecules and to understand the influence of the coordination sphere on the stability and on the electronic relaxation and on the other hand, to use the ligand as a chromophore for the development of luminescent probes for biomedical imaging. We present the structure, the stability and the relaxivity of Gd(III) complexes of two series of tripodal ligands containing picolinate units based either on the 1,4,7-tri-aza-cyclononane ring or on a tertiary amine. These complexes show high relaxivity in water and in serum and can establish a non covalent interaction with serum albumin. The interpretation of the water proton relaxivity with the help of new relaxometric methods based on an auxiliary probe solute has allowed us to show that both the presence of the picolinate groups and the 1,4,7-tri-aza-cyclononane framework can lead to Gd(III) complexes with favourable electronic relaxation properties. This ligands have also been used for Eu(III) and Tb(III) complexation leading to strong luminescence in visible light. Other complexes derived from 8-hydroxyquinoline unit which display a very high luminescence in infrared are also studied. (author)

  5. Ionic liquids as a novel solvent for lanthanide extraction.

    Science.gov (United States)

    Nakashima, Kazunori; Kubota, Fukiko; Maruyama, Tatsuo; Goto, Masahiro

    2003-08-01

    Octyl(phenyl)-N,N-diisobutylcarbamoylmethyl phosphine oxide (CMPO) dissolved in an ionic liquids, 1-butyl-3-methyl-imidazolium hexafluorophosphate, greatly enhances extractability and selectivity of lanthanide cations compared to that dissolved in conventional organic solvents; further, the recovery of lanthanides extracted into ionic liquids can be accomplished using several stripping solutions containing complexing agents. The possibility of utilizing ionic liquids as novel separation media in an industrial liquid-liquid extraction process was demonstrated. PMID:12945658

  6. Lanthanide complexes of some high energetic compounds (I), crystal structures and thermal properties of 3-nitro-1,2,4-triazole-5-one (NTO) complexes

    International Nuclear Information System (INIS)

    The title complexes with NTO ligand, [Pr2(NTO)4(H2O)10].2NTO.6H2O, I; [Gd(NTO)2(H2O)6].NO3.2H2O, II; [Ho(NTO)2(H2O)6].NO3.2H2O, III, have been synthesized and their crystal structures analyzed by X-ray diffraction methods. Complex I crystallized in the monoclinic Pc space group; II, triclinic Pi; III, monoclinic P21/n. In complex I, the Pr(III) atoms have two different coordination numbers. Ten coordinated Pr(1) atom forms two five-membered chelate rings by combining two NTO ligands bridged to Pr(2) atom. Eight coordinated Pr(2) atom has two terminal NTO ligands and two NTO ligands bridged to Pr(1) atom. Bridging of NTO ligands between Pr(1) and Pr(2), give a novel infinite one-dimensional coordination polymer. There are two free NTO molecules and six crystalline water molecules in the crystal lattice. In iso-structural complexes II and III, the Gd(III) and Ho(III) atoms have eight coordinated by two carbonyl O atoms of two different NTO rings and six water molecules, respectively. There are one NO3 ion and two crystalline water molecules in the crystal lattice. The crystal structures are stabilized by three-dimensional network of the intermolecular N-H...ONitrate and N-H...NNTO hydrogen bonds. Based on the results of TG-DTG thermal analysis, the thermal decomposition reaction of complex I was analyzed to have three distinctive stages such as the dehydration of water, the cleavage of NTO ring and the formation of metal oxide, while complexes II and III were proceeded through four stages including the decomposition of NO3 ion

  7. Toward stereoselective lactide polymerization catalysts: cationic zinc complexes supported by a chiral phosphinimine scaffold.

    Science.gov (United States)

    Sun, Hongsui; Ritch, Jamie S; Hayes, Paul G

    2011-09-01

    The P-stereogenic phosphinimine ligands (dbf)MePhP═NAr (7: Ar = Dipp; 8: Ar = Mes; dbf = dibenzofuran, Dipp = 2,6-diisopropylphenyl, Mes = 2,4,6-trimethylphenyl) were synthesized as racemates via reactions of the parent phosphines (rac)-(dbf)MePhP (6) with organoazides. The ligands 7 and 8 were protonated by Brønsted acids to afford the aminophosphonium borate salts [(7)-H][BAr(4)] (9: Ar = C(6)F(5); 11: Ar = Ph) and [(8)-H][BAr(4)] (10: Ar = C(6)F(5); 12: Ar = Ph). The protonated ligands 9 and 10 were active toward alkane elimination reactions with diethylzinc and ethyl-[methyl-(S)-lactate]zinc to give the heteroleptic complexes [{(dbf)MePhP═NAr}ZnR][B(C(6)F(5))(4)] (Ar = Dipp, 13: R = Et; 15: R = methyl-(S)-lactate; Ar = Mes, 14: R = Et; 16: R = methyl-(S)-lactate). By contrast, reaction of the tetraphenylborate derivative 11 with diethylzinc yielded a phenyl transfer product, [(dbf)MePhP═NDipp]ZnPh(2) (17). Complex 15 was found to catalyze the ring-opening polymerization of rac-lactide. PMID:21790171

  8. Chiral Recognition for the Two Enantiomers of Phenylalanine and Four Amino Acid Derivatives with (S)-Phenylethylamine Derived Nickel(II) Macrocyclic Complex

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Jeong Jae; Ryoo, Jae Jeong [Kyungpook National Univ., Daegu (Korea, Republic of)

    2013-11-15

    The potency of new chiral selector candidate was assessed by this simple chiral discrimination test. This experiment showed that the macrocyclic molecule can be a powerful candidate as a chiral selector to obtain optically pure amino acid or amino acid derivatives, particularly phenylalanine and N-benzoyl-phenylalanine enantiomers from racemic mixtures. This study attempted to use the chiral metal organic framework (MOF), 1, as a good chiral selector candidate for the chiral discrimination of racemic phenylalanine, N-benzoyl-alanine, N-benzoyl-phenylalanine, N-benzoyl-methionine, N-CBZ-alanine. The chiral recognition ability of the chiral macromolecule, was examined by varying the molar ratio of the macromolecule and racemates.

  9. Chiral Recognition for the Two Enantiomers of Phenylalanine and Four Amino Acid Derivatives with (S)-Phenylethylamine Derived Nickel(II) Macrocyclic Complex

    International Nuclear Information System (INIS)

    The potency of new chiral selector candidate was assessed by this simple chiral discrimination test. This experiment showed that the macrocyclic molecule can be a powerful candidate as a chiral selector to obtain optically pure amino acid or amino acid derivatives, particularly phenylalanine and N-benzoyl-phenylalanine enantiomers from racemic mixtures. This study attempted to use the chiral metal organic framework (MOF), 1, as a good chiral selector candidate for the chiral discrimination of racemic phenylalanine, N-benzoyl-alanine, N-benzoyl-phenylalanine, N-benzoyl-methionine, N-CBZ-alanine. The chiral recognition ability of the chiral macromolecule, was examined by varying the molar ratio of the macromolecule and racemates

  10. Structure and bonding of some newly synthesized complexes of lanthanide(III) complexes of 4[N-(p-dimetaylaminobenzalidene) amino] antipyrine thiosemicarbazone

    International Nuclear Information System (INIS)

    A series of complexes of the type LnX3.2(DABAAPTS), where Ln = La, Pr, Nd, Sm, Gd, Tb, Dy and Ho, X = ClO4-, or NCS-, DABAAPTS=4[N- (p-dimethylaminobenzalidene) amino] anti pyrine thiosemicarbazone have been synthesized and characterized on the basis of elemental analysis, molecular weight measurements, molar conductance, room temperature magnetic moment, infrared and electronic spectral data. The ligand DABAAPTS behaves as neutral tridentate (N2S) ligand. (author)

  11. Coordination Complexes of Decamethylytterbocene with4,4'-Disubstituted Bipyridines: An Experimental Study of Spin Coupling inLanthanide Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Walter, Marc D.; Berg, David J.; Andersen, Richard A.

    2005-12-08

    The paramagnetic 1:1 coordination complexes of (C5Me5)2Ybwith a series of 4,4'-disubstituted bipyridines, bipy-X, where X is Me,tert-Bu, OMe, Ph, CO2Me, and CO2Et have been prepared. All of thecomplexes are paramagnetic and the values of the magnetic susceptibilityas a function of temperature show that these values are less thanexpected for the cation, [(C5Me5)2Yb(III)(bipy-X)]+, which have beenisolated as the cation-anion ion-pairs[(C5Me5)2Yb(III)(bipy-X)]+[(C5Me5)2YbI2]f fnfn where X is CO2Et, OMe andMe. The 1H NMR chemical shifts (293 K) for the methine resonances locatedat the 6,6' site in the bipy-X ring show a linear relationship with thevalues of chiT (300 K) for the neutral complexes which illustrates thatthe molecular behavior does not depend upon the phase with one exception,viz., (C5Me5)2Yb(bipy-Me). Single crystals of the 4,4'-dimethylbipyridinecomplex undergo an irreversible, abrupt first order phase change at 228 Kthat shatters the single crystals. The magnetic susceptibility,represented in a delta vs. T plot, on this complex, in polycrystallineform undergoes reversible abrupt changes in the temperature regime 205 -212 K, which is suggested to be due to the way the individual molec ularunits pack in the unit cell. A qualitative model is proposed thataccounts for the sub-normal magnetic moments in theseytterbocene-bipyridine complexes.

  12. A Novel Cu-based Metallosalan Complex:Synthesis, Structure and Chiral Sensor Study

    Institute of Scientific and Technical Information of China (English)

    YE Cheng-Cheng; ZHU Cheng-Feng; GONG Teng-Fei; SHENG En-Hong; XUAN Wei-Min; CUI Yong; LIU Bai-Zhan

    2013-01-01

    Dipyridyl-functionalized salan ligand (H2L) was synthesized to construct a mononuclear Cu(salan) complex,[CuL(CH3CN)2(H2O)6] (1),through diffusion method.1 was characterized by IR,microanalysis,TGA and single-crystal X-ray crystallography.It crystallizes in orthorhombic space group P21212 with a =17.6640(16),b =18.6750(16),c =16.0625(14) (A),V =5298.6(8) (A)3,Z =4,Mr =994.70,Dc =1.247 g/cm3,F(000) =2116,μ =0.469 mm-1,GOOF =1.073,the final R =0.0499 and wR =0.1395 for 11816 observed reflections with Ⅰ > 2σ(Ⅰ).In the title compound,the basic building unit consists of two mononuclear Cu(salan) which orient in opposite directions and are locked together via weak intermolecular C-H…r interactions.The adjacent building units are further directed into a 2D supramolecular network structure via H bonds,between which reside the guest acetonitrile and water molecules.In addition,the presence of exposed NH-functionalities and coordination unsaturated Cu centers in 1 provide a great chance to recognize tartaric acids through CD titration in solution.

  13. Chiral superconductors

    Science.gov (United States)

    Kallin, Catherine; Berlinsky, John

    2016-05-01

    Chiral superconductivity is a striking quantum phenomenon in which an unconventional superconductor spontaneously develops an angular momentum and lowers its free energy by eliminating nodes in the gap. It is a topologically non-trivial state and, as such, exhibits distinctive topological modes at surfaces and defects. In this paper we discuss the current theory and experimental results on chiral superconductors, focusing on two of the best-studied systems, Sr2RuO4, which is thought to be a chiral triplet p-wave superconductor, and UPt3, which has two low-temperature superconducting phases (in zero magnetic field), the lower of which is believed to be chiral triplet f-wave. Other systems that may exhibit chiral superconductivity are also discussed. Key signatures of chiral superconductivity are surface currents and chiral Majorana modes, Majorana states in vortex cores, and the possibility of half-flux quantum vortices in the case of triplet pairing. Experimental evidence for chiral superconductivity from μSR, NMR, strain, polar Kerr effect and Josephson tunneling experiments are discussed.

  14. Giant exchange interaction in mixed lanthanides

    Science.gov (United States)

    Vieru, Veacheslav; Iwahara, Naoya; Ungur, Liviu; Chibotaru, Liviu F.

    2016-04-01

    Combining strong magnetic anisotropy with strong exchange interaction is a long standing goal in the design of quantum magnets. The lanthanide complexes, while exhibiting a very strong ionic anisotropy, usually display a weak exchange coupling, amounting to only a few wavenumbers. Recently, an isostructural series of mixed (Ln = Gd, Tb, Dy, Ho, Er) have been reported, in which the exchange splitting is estimated to reach hundreds wavenumbers. The microscopic mechanism governing the unusual exchange interaction in these compounds is revealed here by combining detailed modeling with density-functional theory and ab initio calculations. We find it to be basically kinetic and highly complex, involving non-negligible contributions up to seventh power of total angular momentum of each lanthanide site. The performed analysis also elucidates the origin of magnetization blocking in these compounds. Contrary to general expectations the latter is not always favored by strong exchange interaction.

  15. Giant exchange interaction in mixed lanthanides.

    Science.gov (United States)

    Vieru, Veacheslav; Iwahara, Naoya; Ungur, Liviu; Chibotaru, Liviu F

    2016-01-01

    Combining strong magnetic anisotropy with strong exchange interaction is a long standing goal in the design of quantum magnets. The lanthanide complexes, while exhibiting a very strong ionic anisotropy, usually display a weak exchange coupling, amounting to only a few wavenumbers. Recently, an isostructural series of mixed (Ln = Gd, Tb, Dy, Ho, Er) have been reported, in which the exchange splitting is estimated to reach hundreds wavenumbers. The microscopic mechanism governing the unusual exchange interaction in these compounds is revealed here by combining detailed modeling with density-functional theory and ab initio calculations. We find it to be basically kinetic and highly complex, involving non-negligible contributions up to seventh power of total angular momentum of each lanthanide site. The performed analysis also elucidates the origin of magnetization blocking in these compounds. Contrary to general expectations the latter is not always favored by strong exchange interaction. PMID:27087470

  16. Spectrally resolved confocal microscopy using lanthanide centred near-IR emission

    DEFF Research Database (Denmark)

    Liao, Zhiyu; Tropiano, Manuel; Mantulnikovs, Konstantins;

    2015-01-01

    The narrow, near infrared (NIR) emission from lanthanide ions has attracted great interest, particularly with regard to developing tools for bioimaging, where the long lifetimes of lanthanide excited states can be exploited to address problems arising from autofluorescence and sample transparency....... Despite the promise of lanthanide-based probes for near-IR imaging, few reports on their use are present in the literature. Here, we demonstrate that images can be recorded by monitoring NIR emission from lanthanide complexes using detectors, optical elements and a microscope that were primarily designed...

  17. Separation of light lanthanides

    International Nuclear Information System (INIS)

    A plan is presented for separating the ternary mixture of La, Nd and Pr at a joint utilization of the methods of fractional counter-current extraction and of ammonia barbotage (Trombe method) carried out by the applied Trombe method. At concentrations of lanthanides of the order of 100 g/l La and Nd concentrates were achieved this were further processed by the method of fractional counter-current extraction. (author)

  18. Parity violation in nuclear magnetic resonance frequencies of chiral tetrahedral tungsten complexes NWXYZ (X, Y, Z = H, F, Cl, Br or I)

    CERN Document Server

    Nahrwold, Sophie; Schwerdtfeger, Peter

    2014-01-01

    Density functional theory within the two-component quasi-relativistic zeroth-order regular approximation (ZORA) is used to predict parity violation shifts in 183W nuclear magnetic resonance shielding tensors of chiral, tetrahedrally bonded tungsten complexes of the form NWXYZ (X, Y, Z = H, F, Cl, Br or I). The calculations reveal that sub-mHz accuracy is required to detect such tiny effects in this class of compounds, and that parity violation effects are very sensitive to the choice of ligands.

  19. Enantioselective synthesis of dihydrocoumarin derivatives by chiral scandium(III)-complex catalyzed inverse-electron-demand hetero-Diels-Alder reaction.

    Science.gov (United States)

    Hu, Haipeng; Liu, Yangbin; Guo, Jing; Lin, Lili; Xu, Yali; Liu, Xiaohua; Feng, Xiaoming

    2015-03-01

    An asymmetric inverse-electron-demand hetero-Diels-Alder reaction between o-quinone methides and azlactones to generate potentially pharmacological active dihydrocoumarins has been achieved efficiently by using a chiral N,N'-dioxide-Sc(III) complex as the catalyst. The desired products were obtained in high yields with excellent enantioselectivities and diastereoselectivities (up to 94% yield, 96% ee and >19 : 1 dr) under mild reaction conditions. A concerted reaction pathway was confirmed by Operando IR and control experiments. PMID:25649623

  20. Asymmetric Ring-Opening of Cyclopropyl Ketones with Thiol, Alcohol, and Carboxylic Acid Nucleophiles Catalyzed by a Chiral N,N'-Dioxide-Scandium(III) Complex.

    Science.gov (United States)

    Xia, Yong; Lin, Lili; Chang, Fenzhen; Fu, Xuan; Liu, Xiaohua; Feng, Xiaoming

    2015-11-01

    A highly efficient asymmetric ring-opening reaction of cyclopropyl ketones with a broad range of thiols, alcohols and carboxylic acids has been first realized by using a chiral N,N'-dioxide-scandium(III) complex as catalyst. The corresponding sulfides, ethers, and esters were obtained in up to 99% yield and 95% ee. This is also the first example of one catalytic system working for the ring-opening reaction of donor-acceptor cyclopropanes with three different nucleophiles, let alone in an asymmetric version. PMID:26398505

  1. Enantioseparations of chiral alpha-diimine Ru(II) and Fe(II) complexes by capillary electrophoresis using sulfated cyclodextrins as stereoselectors

    Czech Academy of Sciences Publication Activity Database

    Sázelová, Petra; Koval, Dušan; Severa, Lukáš; Teplý, Filip; Kašička, Václav

    Pardubice: Univerzita Pardubice, 2014 - (Horna, A.; Jandera, P.). s. 103 ISBN 978-80-7395-777-3. [ISSS 2014. International Symposium on Separation Sciences /20./. 30.08.2014-02.09.2014, Praha] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S; GA ČR GA13-32974S Institutional support: RVO:61388963 Keywords : alpha-diimine Ru(II) complex * capillary electrophoresis * chiral separation Subject RIV: CB - Analytical Chemistry, Separation

  2. Chiral analysis of alfa-diimine Ru(II) and Fe(II) complexes by capillary electrophoresis using sulfated cyclodextrins as stereoselectors

    Czech Academy of Sciences Publication Activity Database

    Sázelová, Petra; Koval, Dušan; Severa, Lukáš; Teplý, Filip; Kašička, Václav

    Olomouc: Palacký University, 2014 - (Maier, V.; Ševčík, J.), s. 198-199 ISBN 978-80-244-3950-1. ISSN 0232-0061. [Advances in Chromatography and Electrophoresis & Chiranal 2014. Olomouc (CZ), 10.02.2014-14.02.2014] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S; GA ČR GA13-32974S Institutional support: RVO:61388963 Keywords : capillary electrophoresis * chiral analysis * metal-polypyridyl complexes Subject RIV: CB - Analytical Chemistry, Separation

  3. Baryon chiral perturbation theory

    International Nuclear Information System (INIS)

    We provide a short introduction to the one-nucleon sector of chiral perturbation theory and address the issue of power counting and renormalization. We discuss the infrared regularization and the extended on-mass-shell scheme. Both allow for the inclusion of further degrees of freedom beyond pions and nucleons and the application to higher-loop calculations. As applications we consider the chiral expansion of the nucleon mass to order O(q6) and the inclusion of vector and axial-vector mesons in the calculation of nucleon form factors. Finally, we address the complex-mass scheme for describing unstable particles in effective field theory.

  4. Baryon chiral perturbation theory

    CERN Document Server

    Scherer, Stefan

    2011-01-01

    We provide a short introduction to the one-nucleon sector of chiral perturbation theory and address the issue of power counting and renormalization. We discuss the infrared regularization and the extended on-mass-shell scheme. Both allow for the inclusion of further degrees of freedom beyond pions and nucleons and the application to higher-loop calculations. As applications we consider the chiral expansion of the nucleon mass to order ${\\cal O}(q^6)$ and the inclusion of vector and axial-vector mesons in the calculation of nucleon form factors. Finally, we address the complex-mass scheme for describing unstable particles in effective field theory.

  5. Baryon chiral perturbation theory

    Science.gov (United States)

    Scherer, S.

    2012-03-01

    We provide a short introduction to the one-nucleon sector of chiral perturbation theory and address the issue of power counting and renormalization. We discuss the infrared regularization and the extended on-mass-shell scheme. Both allow for the inclusion of further degrees of freedom beyond pions and nucleons and the application to higher-loop calculations. As applications we consider the chiral expansion of the nucleon mass to order Script O(q6) and the inclusion of vector and axial-vector mesons in the calculation of nucleon form factors. Finally, we address the complex-mass scheme for describing unstable particles in effective field theory.

  6. Triflate-functionalized calix[6]arenes as versatile building-blocks: application to the synthesis of an inherently chiral Zn(ii) complex.

    Science.gov (United States)

    Zahim, Sara; Lavendomme, Roy; Reinaud, Olivia; Luhmer, Michel; Evano, Gwilherm; Jabin, Ivan

    2016-02-14

    Cavity-based metal complexes can find many applications notably in the fields of catalysis and biomimicry. In this context, it was shown that metal complexes of calix[6]arenes bearing three aza-coordinating arms at the small rim provide excellent structural models of the poly-imidazole sites found in the active site of many metallo-enzymes. All these N-donor ligands were synthesized from the 1,3,5-tris-methoxy-p-tBu-calix[6]arene platform, which presents some limitations in terms of functionalization. Therefore, there is a need for the development of new calix[6]arene-based building-blocks selectively protected at the small rim. Herein we describe the regioselective one step synthesis of two calix[6]arenes decorated with triflate groups, i.e. X6H4Tf2 and X6H3Tf3, from the parent calix[6]arene X6H6. It is shown that the triflate groups can either act as protecting or deactivating groups, allowing the elaboration of sophisticated calixarene-based systems selectively functionalized at the large and/or at the small rim. In addition, X6H3Tf3 is functionalized on the A, B, and D rings and thus gives access to inherently chiral compounds, as demonstrated by the synthesis of a rare example of inherently chiral cavity-based metal complex. PMID:26751614

  7. Half-sandwich (6-arene)ruthenium(II) chiral Schiff base complexes: Analysis of the diastereomeric mixtures in solution by 2D-NMR spectroscopy

    Indian Academy of Sciences (India)

    Rakesh K Rath; G A Nagana Gowda; Akhil R Chakravarty

    2002-10-01

    2D NMR spectroscopy has been used to determine the metal configuration in solution of three complexes, viz. [($\\eta^6$--cymene)Ru(L∗)Cl] (1) and [(6--cymene)Ru(L∗)(L')] (ClO4) (L' = H2O, 2; PPh3, 3), where L∗ is the anion of ()-(1-phenylethyl)salicylaldimine. The complexes exist in two diastereomeric forms in solution. Both the (Ru, C)- and (Ru, C)-diastereomers display the presence of attractive CH/ interaction involving the phenyl group attached to the chiral carbon and the cymene ring hydrogens. This interaction restricts the rotation of the C∗-N single bond and, as a result, two structural types with either the hydrogen atom attached to the chiral carbon (C∗) or the methyl group attached to C∗ in close proximity of the cymene ring protons get stabilized. Using 2D NMR spectroscopy as a tool, the spatial interaction involving these protons are studied in order to obtain the metal configuration(s) of the diastereomeric complexes in solution. This technique has enabled us to determine the metal configuration as (Ru, C) for the major isomers of 1-3 in solution.

  8. Complexations of Ln(III) with SnS{sub 4}H and Sn{sub 2}S{sub 6}: Solvothermal syntheses and characterizations of lanthanide coordination polymers with thiostannate and polyamine mixed ligands

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Chunying; Lu, Jialin; Han, Jingyu; Liu, Yun; Shen, Yali; Jia, Dingxian, E-mail: jiadingxian@suda.edu.cn

    2015-10-15

    Polymeric lanthanide complexes with thiostannate and polyamine mixed ligands, [Ln(peha)(μ–SnS{sub 4}H)]{sub n} [Ln=La (1a), Nd (1b)] and [(Ln(tepa)(μ–OH)){sub 2}(μ–Sn{sub 2}S{sub 6})]{sub n}nH{sub 2}O [Ln=Nd (2a), Sm (2b), Gd (2c), Dy (2d)] (peha=pentaethylenehexamine, tepa=tetraethylenepentamine) were respectively prepared in peha and tepa coordinative solvents by the solvothermal methods. In 1a and 1b, the Ln{sup 3+} ions are coordinated by a hexadentate peha ligand forming [Ln(peha)]{sup 3+} units. The [SnS{sub 4}H]{sup 3−} anion chelates a [Ln(peha)]{sup 3+} unit via two S atoms and coordinates to another [Ln(peha)]{sup 3+} unit via the third S atom. As a result, the [Ln(peha)]{sup 3+} units are connected into coordination polymers [Ln(peha)(μ–SnS{sub 4}H)]{sub n} by an unprecedented tridentate μ–η{sup 1},η{sup 2}–SnS{sub 4}H bridging ligands. In 2a–2d, the Ln{sup 3+} ions are coordinated by a pentadentate tepa ligand, and two [Ln(tepa)]{sup 3+} units are joined by two μ–OH bridges to form a binuclear [(Ln(tepa)(μ–OH)){sub 2}]{sup 4+} unit. Behaving as a bidentate μ–η{sup 1}, η{sup 1}–Sn{sub 2}S{sub 6} bridging ligand, the Sn{sub 2}S{sub 6} unit connects [(Ln(tepa)(μ–OH)){sub 2}]{sup 4+} units into a neutral coordination polymer [(Ln(tepa)(μ–OH)){sub 2}(μ–Sn{sub 2}S{sub 6})]{sub n} via the trans S atoms. The Ln{sup 3+} ions are in distorted monocapped square antiprismatic and bicapped trigonal prismatic environments in [(Ln(peha)(μ–SnS{sub 4}H)]{sub n} and [(Ln(tepa)(μ–OH)){sub 2}(μ–Sn{sub 2}S{sub 6})]{sub n}, respectively. The denticities of ethylene polyamine play an important role on the formation and complexation of the thiostannate in the presence of lanthanide ions. Compounds 1a–2d show well-defined absorption edges with band gaps between 2.81 and 3.15 eV. - Graphical abstract: Lanthanide coordination polymers concerning thiostannate ligands were prepared by the solvothermal methods, and μ{sub 3}

  9. Complexations of Ln(III) with SnS4H and Sn2S6: Solvothermal syntheses and characterizations of lanthanide coordination polymers with thiostannate and polyamine mixed ligands

    International Nuclear Information System (INIS)

    Polymeric lanthanide complexes with thiostannate and polyamine mixed ligands, [Ln(peha)(μ–SnS4H)]n [Ln=La (1a), Nd (1b)] and [(Ln(tepa)(μ–OH))2(μ–Sn2S6)]nnH2O [Ln=Nd (2a), Sm (2b), Gd (2c), Dy (2d)] (peha=pentaethylenehexamine, tepa=tetraethylenepentamine) were respectively prepared in peha and tepa coordinative solvents by the solvothermal methods. In 1a and 1b, the Ln3+ ions are coordinated by a hexadentate peha ligand forming [Ln(peha)]3+ units. The [SnS4H]3− anion chelates a [Ln(peha)]3+ unit via two S atoms and coordinates to another [Ln(peha)]3+ unit via the third S atom. As a result, the [Ln(peha)]3+ units are connected into coordination polymers [Ln(peha)(μ–SnS4H)]n by an unprecedented tridentate μ–η1,η2–SnS4H bridging ligands. In 2a–2d, the Ln3+ ions are coordinated by a pentadentate tepa ligand, and two [Ln(tepa)]3+ units are joined by two μ–OH bridges to form a binuclear [(Ln(tepa)(μ–OH))2]4+ unit. Behaving as a bidentate μ–η1, η1–Sn2S6 bridging ligand, the Sn2S6 unit connects [(Ln(tepa)(μ–OH))2]4+ units into a neutral coordination polymer [(Ln(tepa)(μ–OH))2(μ–Sn2S6)]n via the trans S atoms. The Ln3+ ions are in distorted monocapped square antiprismatic and bicapped trigonal prismatic environments in [(Ln(peha)(μ–SnS4H)]n and [(Ln(tepa)(μ–OH))2(μ–Sn2S6)]n, respectively. The denticities of ethylene polyamine play an important role on the formation and complexation of the thiostannate in the presence of lanthanide ions. Compounds 1a–2d show well-defined absorption edges with band gaps between 2.81 and 3.15 eV. - Graphical abstract: Lanthanide coordination polymers concerning thiostannate ligands were prepared by the solvothermal methods, and μ3–SnS4H and μ–Sn2S6 ligands to Ln(III) centers were obtained. - Highlights: • Lanthanide coordination polymers were prepared in polyamines with higher denticity. • The μ–η1,η2–SnS4H and μ–η1,η1–Sn2S6 ligands to Ln(III) centers were

  10. Lanthanide extraction with 2,5-dimethyl-2-hydroxyhexanoic acid

    International Nuclear Information System (INIS)

    This research is concerned with the solvent extraction into chloroform of the lanthanides, using 2,5-dimethyl-2-hydroxyhexanoic acid (DMHHA). This acid is the first α-hydroxy aliphatic acid to be studied as an extracting agent for the lanthanides. The chloroform-water DMHHA partition constant was determined to be 1.0 (at 0.1 M ionic strength and 250C). The acid dimerizes in chloroform with a constant of 56. The light lanthanides can be extracted into chloroform by forming complexes with the DMHHA anions. The extracted metal species is highly aggregated. This extraction has a solubility limit which increases with the addition of unionized acid. The resultant extract is also highly aggregated. At unionized acid-to-metal ratios greater than one, extractions first occur followed by the slow precipitation of the lanthanide. At the tracer level, neodymium is extracted primarily as NdA3(HA)5 and (NdA3)2(HA)/sub q/. Very small amounts of (NdA3)2 and other metal aggregates are also present. The heavy lanthanides do not extract from solutions of DMHHA and its potassium salt, but form aqueous emulsions and precipitates. In the presence of the organic soluble tetrabutylammonium ion the heavy lanthanides can be extracted, presumably as ion pairs. The stability constants of the light lanthanides and DMHHA were determined. The separation factors obtained from DMHHA extractions of the light lanthanides were also investigated and found to be comparable to those obtained employing normal aliphatic carboxylic acid

  11. New Lanthanide Alkynylamidinates and Diiminophosphinates

    Directory of Open Access Journals (Sweden)

    Farid M. Sroor

    2015-11-01

    Full Text Available This contribution reports the synthesis and structural characterization of several new lithium and lanthanide alkynylamidinate complexes. Treatment of PhC≡CLi with N,N′-diorganocarbodiimides, R–N=C=N–R (R = iPr, Cy (cyclohexyl, in THF or diethyl ether solution afforded the lithium-propiolamidinates Li[Ph–C≡C–C(NCy2] S (1: R = iPr, S = THF; 2: R = Cy, S = THF; 3: R = Cy, S = Et2O. Single-crystal X-ray diffraction studies of 1 and 2 showed the presence of typical ladder-type dimeric structures in the solid state. Reactions of anhydrous LnCl3 (Ln = Ce, Nd, Sm or Ho with 2 in a 1:3 molar ratio in THF afforded a series of new homoleptic lanthanide tris(propiolamidinate complexes, [Ph–C≡C–C(NCy2]3Ln (4: Ln = Ce; 5: Ln = Nd; 6: Ln = Sm; 7: Ln = Ho. The products were isolated in moderate to high yields (61%–89% as brightly colored, crystalline solids. The chloro-functional neodymium(III bis(cyclopropylethynylamidinate complex [{c-C3H5–C≡C–C(NiPr2}2Ln(µ-Cl(THF]2 (8 was prepared from NdCl3 and two equiv. of Li[c-C3H5–C≡C–C(NiPr2] in THF and structurally characterized. A new monomeric Ce(III-diiminophosphinate complex, [Ph2P(NSiMe32]2Ce(µ-Cl2Li(THF2 (9, has also been synthesized in a similar manner from CeCl3 and two equiv. of Li[Ph2P(NSiMe32]. Structurally, this complex resembles the well-known “ate” complexes (C5Me52Ln(µ-Cl2Li(THF2. Attempts to oxidize compound 9 using trityl chloride or phenyliodine(III dichloride did not lead to an isolable cerium(IV species.

  12. Isotopic chirality

    Energy Technology Data Exchange (ETDEWEB)

    Floss, H.G. [Univ. of Washington, Seattle, WA (United States)

    1994-12-01

    This paper deals with compounds that are chiral-at least in part, due to isotope substitution-and their use in tracing the steric course of enzyme reaction in vitro and in vivo. There are other applications of isotopically chiral compounds (for example, in analyzing the steric course of nonenzymatic reactions and in probing the conformation of biomolecules) that are important but they will not be discussed in this context.

  13. Adducts compounds of lanthanides (III) trifluoreacetates and yttrium and the N,N - dimenthylformamide

    International Nuclear Information System (INIS)

    Some studies on lanthanides, f transition elements, and yttrium are presented. Adducts of lanthanides trifluoroacetates and N,N -dimethylformamide are described. The characterization of complexes from elementar analysis, conductance measurements, X-ray patterns, vibrational, electronics and fluorescence spectra are analysed. (M.J.C.)

  14. Molecular modeling of the binding mode of chiral metal complexes A- and A-[Co(phen)2dppz]3+ with B-DNA

    Institute of Scientific and Technical Information of China (English)

    杨频; 韩大雄

    2000-01-01

    Molecular modeling methods have been applied to the structural characterization of the interaction between chiral metal complexes [Co(phen)2dppz]3+ (where phen = 1, 10-phenanthroline, dppz = dipyrido[3,2-a: 2’, 3’-c]phenazine) and the oligonucleotide (B-DNA fragment). The natures of two kinds of the binding modes, which are currently intense controversy, have been explored. Barton proposed that there is enantio-selective DMA binding by the octahedral complexes and intercalative access by these complexes from the major groove; but Norden suggested that both enantiomers bind extremely strongly to DNA from the minor groove without any noticeable enantio-selectivity. Our results support and extend structural models based upon Norden’s studies, and conflict with Barton’s model.

  15. Molecular modeling of the binding mode of chiral metal complexes △- and (A)-[Co(phen)2dppz]3+ with B-DNA

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Molecular modeling methods have been applied to the structural characterization of the interaction between chiral metal complexes [Co(phen)2dppz]3+ (where phen = 1, 10-phenanthroline, dppz = dipyrido[3,2-a: 2′, 3′-c]phenazine) and the oligonucleotide (B-DNA fragment). The natures of two kinds of the binding modes, which are currently intense controversy, have been explored. Barton proposed that there is enantio-selective DNA binding by the octahedral complexes and intercalative access by these complexes from the major groove; but Norden suggested that both enantiomers bind extremely strongly to DNA from the minor groove without any noticeable enantio-selectivity. Our results support and extend structural models based upon Norden's studies, and conflict with Barton's model.

  16. Lanthanide-halide based humidity indicators

    Science.gov (United States)

    Beitz, James V.; Williams, Clayton W.

    2008-01-01

    The present invention discloses a lanthanide-halide based humidity indicator and method of producing such indicator. The color of the present invention indicates the humidity of an atmosphere to which it is exposed. For example, impregnating an adsorbent support such as silica gel with an aqueous solution of the europium-containing reagent solution described herein, and dehydrating the support to dryness forms a substance with a yellow color. When this substance is exposed to a humid atmosphere the water vapor from the air is adsorbed into the coating on the pore surface of the silica gel. As the water content of the coating increases, the visual color of the coated silica gel changes from yellow to white. The color change is due to the water combining with the lanthanide-halide complex on the pores of the gel.

  17. Intercalation of lanthanide trichlorides in graphite

    International Nuclear Information System (INIS)

    The reactions of the whole series of lanthanide trichlorides with graphite have been investigated. Intercalation compounds have been prepared with the chlorides of Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, Y whereas LaCl3, CeCl3, PrCl3 and NdCl3 do not intercalate. The compounds were characterized by chemical and X-ray analysis. The amount of c-axis increase is consistent with the assumption that the chlorides are intercalated in form of a chloride layer sandwich resmbling the sheets in YCl3. The chlorides which do not intercalate crystallize in the UCl3 structure having 3 D arrangements of ions. Obviously, these chlorides cannot form sheets between the carbon layers. The ability of AlCl3 to volatilize lanthanide chlorides through complex formation in the gas phase can be used to increase the intercalation rate strikingly. (author)

  18. The lanthanides and actinides

    International Nuclear Information System (INIS)

    This paper relates the chemical properties of the actinides to their position in the Mendeleev periodic system. The changes in the oxidation states of the actinides with increasing atomic number are similar to those of the 3d elements. Monovalent and divalent actinides are very similar to alkaline and alkaline earth elements; in the 3+ and 4+ oxidation states they resemble d elements in the respective oxidation states. However, in their highest oxidation states the actinides display their individual properties with only a slight resemblance to d elements. Finally, there is a profound similarity between the second half of the actinides and the first half of the lanthanides

  19. Effective core potential methods for the lanthanides

    International Nuclear Information System (INIS)

    In this paper a complete set of effective core potentials (ECPs) and valence basis sets for the lanthanides (Ce to Lu) are derived. These ECPs are consistent not only within the lanthanide series, but also with the third-row transition metals which bracket them. A 46-electron core was chosen to provide the best compromise between computational savings and chemical accuracy. Thus, the 5s and 5p are included as ''outer'' core while all lower energy atomic orbitals (AOs) are replaced with the ECP. Generator states were chosen from the most chemically relevant +3 and +2 oxidation states. The results of atomic calculations indicate that the greatest error vs highly accurate numerical potential/large, even-tempered basis set calculations results from replacement of the large, even-tempered basis sets with more compact representations. However, the agreement among atomic calculations remains excellent with both basis set sizes, for a variety of spin and oxidation states, with a significant savings in time for the optimized valence basis set. It is expected that the compact representation of the ECPs and valence basis sets will eventually encourage their use by computational chemists to further explore the bonding and reactivity of lanthanide complexes

  20. Punctuated Chirality

    Science.gov (United States)

    Gleiser, Marcelo; Thorarinson, Joel; Walker, Sara Imari

    2008-12-01

    Most biomolecules occur in mirror, or chiral, images of each other. However, life is homochiral: proteins contain almost exclusively L-amino acids, while only D-sugars appear in RNA and DNA. The mechanism behind this fundamental asymmetry of life remains an open problem. Coupling the spatiotemporal evolution of a general autocatalytic polymerization reaction network to external environmental effects, we show through a detailed statistical analysis that high intensity and long duration events may drive achiral initial conditions towards chirality. We argue that life’s homochirality resulted from sequential chiral symmetry breaking triggered by environmental events, thus extending the theory of punctuated equilibrium to the prebiotic realm. Applying our arguments to other potentially life-bearing planetary platforms, we predict that a statistically representative sampling will be racemic on average.

  1. Punctuated Chirality

    CERN Document Server

    Gleiser, Marcelo; Walker, Sara Imari

    2008-01-01

    Most biomolecules occur in mirror, or chiral, images of each other. However, life is homochiral: proteins contain almost exclusively levorotatory (L) amino acids, while only dextrorotatory (R) sugars appear in RNA and DNA. The mechanism behind this fundamental asymmetry of life remains an open problem. Coupling the spatiotemporal evolution of a general autocatalytic polymerization reaction network to external environmental effects, we show through a detailed statistical analysis that high intensity and long duration events may drive achiral initial conditions towards chirality. We argue that life's homochirality resulted from sequential chiral symmetry breaking triggered by environmental events, thus extending the theory of punctuated equilibrium to the prebiotic realm. Applying our arguments to other potentially life-bearing planetary platforms, we predict that a statistically representative sampling will be racemic on average.

  2. Chiral morphing

    CERN Document Server

    Chang, N P

    1994-01-01

    Chiral symmetry undergoes a metamorphosis at T.sub(c). For T < T.sub(c), the usual Noether charge, \\Qa, is dynamically broken by the vacuum. Above T.sub(c), chiral symmetry undergoes a subtle change, and the Noether charge \\underline{{\\em morphs}} into \\Qbeta, with the thermal vacuum now becoming invariant under \\Qbeta. This vacuum is however not invariant under the old \\Qa transformations. As a result, the pion remains strictly massless at high T. The pion propagates in the early universe with a halo. New order parameters are proposed to probe the structure of the new thermal vacuum.

  3. Chiral transparency

    International Nuclear Information System (INIS)

    Color transparency is the vanishing of initial and final state interactions, predicted by QCD to occur in high momentum transfer quasielastic nuclear reactions. For specific reactions involving nucleons, the initial and final state interactions are expected to be dominated by exchanges of pions. We argue that these interactions are also suppressed in high momentum transfer nuclear quasielastic reactions; this is open-quotes chiral transparency.close quotes We show that studies of the e3He→e'Δ++nn reaction could reveal the influence of chiral transparency. copyright 1997 The American Physical Society

  4. Metal-organic frameworks from chiral square-pyramidal copper(II) complexes: Enantiospecific inclusion and perfectly polar alignment of guest and host molecules

    International Nuclear Information System (INIS)

    The physical properties of [CuL12(H2O)] (1) and [CuL22(H2O)] (2) and preparation and crystal structures of the inclusion compounds 1.(P)-C2H4Br2, 2.(M)-C2H4Br2, 1.CH3CN and 2.CH3CN are described. HL1 and HL2 (H represents the dissociable phenolic proton) are the N,O-donor chiral reduced Schiff bases N-(2-hydroxy-5-nitrobenzyl)-(R)-α-methyl-benzylamine and N-(2-hydroxy-5-nitrobenzyl)-(S)-α-methylbenzylamine, respectively. All the compounds crystallize in the non-centrosymmetric space group C2. In the crystal lattice, the host [CuL n2(H2O)] (1 and 2) molecules connected by O-H...O and C-H...O interactions form perfectly polar two-dimensional networks. In these chiral and polar host frameworks, enantiospecific inclusion with polar ordering of the right-handed (P) and the left-handed (M) gauche form of 1,2-dibromoethane as well as polar alignment of acetonitrile molecules are observed. The host and guest molecules are linked by C-H...O interactions. The O-atoms of the nitro substituent on the ligands of 1 and 2 act as the acceptors in all these intermolecular O-H...O and C-H...O interactions. The structures reported in this work provide rare examples of enantiospecific trapping of the chiral rotamers of 1,2-dibromoethane as well as perfectly polar alignment of both guest and host molecules. - Graphical abstract: The square-pyramidal Cu(II) complexes [CuL n2(H2O)] with the bidentate HL n (HL1=N-(2-hydroxy-5-nitrobenzyl)-(R)-α-methyl-benzylamine and HL2=N-(2-hydroxy-5-nitrobenzyl)-(S)-α-methylbenzylamine) form 1:1 host-guest compounds with Br(CH2)2Br and CH3CN. The X-ray structures of these species reveal the enantiospecific confinement of the chiral rotamers of Br(CH2)2Br and perfectly polar ordering of both host and guest molecules in the crystal lattice. The figure shows the polar alignments of (a) [CuL12(H2O)].(P)-C2H4Br2 and (b) [CuL22(H2O)].CH3CN

  5. Potentiometric studies on the complexation equilibria between some trivalent lanthanide metal ions and biologically active 2-hydroxy-1-naphthaldehyde thiosemicarbazone (HNATS)

    International Nuclear Information System (INIS)

    The chelation behaviour of some trivalent lanthanide and yttrium metal ions with biologically active 2-hydroxy-1-naphthaldehyde thiosemicarbazone (HNATS) has been investigated by potentiometric measurements at 20±0.5 deg C in 75% (v/v)dioxane-water medium at various ionic strenghts of sodium perchlorate. The method of Bjerrum and Calvin, as modified by Irving and Rossotti has been used to find out the values of n-bar (average number of ligand bound per metal ion) and pL (free ligand exponent). The formation constants of metal chelates have been computed on a PC-XT computer, using a program patterned after that of Sullivan et al. to give βn values using the weighted least-squares method. The Smin values (Smin=χ2) have been calculated. The order of formation constants of chelates was found to be: La3+3+3+3+3+3+3+3+3+3+. The formation constants of the chelates formed have been correlated to size and ionization potentials of the metal ions. (authors)

  6. New Opportunities for Lanthanide Luminescence

    Institute of Scientific and Technical Information of China (English)

    Jean-Claude G. Bünzli; Steve Comby; Anne-Sophie Chauvin; Caroline D. B. Vandevyver

    2007-01-01

    Trivalent lanthanide ions display fascinating optical properties. The discovery of the corresponding elements and their first industrial uses were intimately linked to their optical properties. This relationship has been kept alive until today when many high-technology applications of lanthanide-containing materials such as energy-saving lighting devices, displays, optical fibers and amplifiers, lasers, responsive luminescent stains for biomedical analyses and in cellulo sensing and imaging, heavily rely on the brilliant and pure-color emission of lanthanide ions. In this review we first outlined the basics of lanthanide luminescence with emphasis on f-f transitions, the sensitization mechanisms, and the assessment of the luminescence efficiency of lanthanide-containing emissive molecular edifices. Emphasis was then put on two fast developing aspects of lanthanide luminescence: materials for telecommunications and light emitting diodes, and biomedical imaging and sensing. Recent advances in NIR-emitting materials for plastic amplifiers and waveguides were described, together with the main solutions brought by researchers to minimize non-radiative deactivation of excited states. The demonstration in 1999 that erbium tris(8-hydroxyquinolinate) displayed a bright green emission suitable for organic light emitting diodes (OLEDs) was followed by realizing that in OLEDs, 25% of the excitation energy leads to singlet states and 75% to triplet states. Since lanthanide ions are good triplet quenchers, they now also play a key role in the development of these lighting devices. Luminescence analyses of biological molecules are among the most sensitive analytical techniques known. The long lifetime of the lanthanide excited states allows time-resolved spectroscopy to be used, suppressing the sample autofluorescence and reaching very low detection limits. Not only visible lanthanide sensors are now ubiquitously provided in medical diagnosis and in cell imaging, but the

  7. Chiral Nanoscience and Nanotechnology

    OpenAIRE

    Dibyendu S. Bag; T.C. Shami; K.U. Bhasker Rao

    2008-01-01

    The paper reviews nanoscale science and technology of chiral molecules/macromolecules-under twosubtopics-chiral nanotechnology and nano-chiral technology. Chiral nanotechnology discusses thenanotechnology, where molecular chirality plays a role in the properties of materials, including molecularswitches, molecular motors, and other molecular devices; chiral supramolecules and self-assembled nanotubesand their functions are also highlighted. Nano-chiral technology  describes the nanoscale appr...

  8. Synthesis and Structures of Two Lanthanide Complexes Containing a Mixed Ligand System: [Ln(Phen){sub 2}(L){sub 3}(HL)]·H{sub 2}O [Ln = La, Ce; Phen = Phenanthroline; HL = Salicylic Acid

    Energy Technology Data Exchange (ETDEWEB)

    Iravani, Effat [UNiv. of Applied Science and Technology, Tehran (Iran, Islamic Republic of); Nami, Navabeh; Nabizadeh, Fatemeh; Bayani, Elham [Islamic Azad Univ., Mazandaran (Iran, Islamic Republic of); Neumueller, Bernhard [Philipps-Universitat Marburg, Marburg (Germany)

    2013-11-15

    The reaction of LnCl{sub 3}·7H{sub 2}O [Ln = La (1), Ce (2)] with salicylic acid (HL) and 1,10-phenanthroline (Phen) at 20 .deg. C in H{sub 2}O/ethanol gave after work-up and recrystallization two novel lanthanide complexes with general formula [Ln(Phen){sub 2}(L){sub 3}(HL)]·H{sub 2}O. Compounds 1 and 2 were characterized by IR and UV-Vis spectroscopy, TGA, CHN as well as by X-ray analysis. According to these results, compounds 1 and 2 are isostructural and contain Ln{sup 3+} ions with coordination number nine. Complexes 1 and 2 consist of two Phen, one neutral HL and three L anions (two L anions act as monodentate ligands and the third one is chelating to Ln{sup 3+}). Thermal decomposition led to primary loss of the Phen molecules. Then HL molecules and finally L moieties left the material to give Ln{sub 2}O{sub 3}.

  9. Aqueous complexes of lanthanides(III) and actinides(III) with the carbonate and sulphate ions. Thermodynamic study by time-resolved laser-induced fluorescence spectroscopy and electro-spray-ionisation mass spectrometry

    International Nuclear Information System (INIS)

    The prediction of the environmental impact of a possible geological disposal of radioactive wastes is supported by the thermodynamic modelling of the radionuclides behaviour in the groundwater. In this framework, the analogy between lanthanides and actinides(III) is confirmed by a critical analysis of the literature and the comparison with experimental results obtained here. The limiting complex, Eu(CO3)33-, is identified by solubility measurements in Na2CO3 solutions. Then the formation constants of the complexes Eu(CO3)i3-2i (i=1-3) and Eu(SO4)i3-2i (i=1-2) are measured by TRLFS. The formation of aqueous LaSO4+ is studied by ESI-MS and is in good agreement with the expected speciation. The enthalpy and entropy of the reaction Cm(CO3)2- + CO32- ↔ Cm(CO3)33- are deduced from TRLFS measurements of the equilibrium constant between 10 and 70 C. The ionic strength effect is calculated using the SIT formula. (author)

  10. Chiral symmetry

    International Nuclear Information System (INIS)

    We present many varied chiral symmetry models at the quark level which consistently describe strong interaction hadron dynamics. The pattern that emerges is a nonstrange current quark mass scale mcur ≅ (34-69) MeV and a current quark mass ratio (ms/m)cur ≅ 5-6 along with no strange quark content in nucleons. (orig./WL)

  11. Chiral Zn(II-Bisamidine Complex as a Lewis-Brønsted Combined Acid Catalyst: Application to Asymmetric Mukaiyama Aldol Reactions of α-Ketoesters

    Directory of Open Access Journals (Sweden)

    Ryo Gotoh

    2012-07-01

    Full Text Available Focusing on the steric and electronic properties of the resonance-stabilized amidine framework, a cationic metal-bisamidine complex was designed as a conjugated combined Lewis-Brønsted acid catalyst. The chiral Zn(II-bisamidine catalyst prepared from the 2,2'-bipyridyl derived bisamidine ligand, ZnCl2, and AgSbF6 promoted asymmetric Mukaiyama aldol reaction of α-ketoester and α,α-disubstituted silyl enol ether to afford the α-hydroxyester having sequential quarternary carbons in good yield, albeit with low enantioselectivity. Addition of 1.0 equivalent of the fluoroalcohol having suitable acidity and bulkiness dramatically increased the enantioselectivity (up to 68% ee. DFT calculations suggested that this additive effect would be caused by self-assembly of the fluoroalcohol on the Zn(II-bisamidine catalyst.

  12. Asymmetric Electrophilic Fluorination of β-Keto Phosphonates in Ionic Liquid Media Catalyzed by Chiral Palladium Complexes

    International Nuclear Information System (INIS)

    We have accomplished the highly efficient catalytic enantioselective fluorination of β-keto phosphonates with excellent yield and enantioselectivity in ionic liquid, which simplify product isolation and catalyst recycling. The chemistry of bioactive organofluorine compounds is a rapidly developing area of research because of their importance in biochemical and medicinal application. Chiral organofluorine compounds containing a fluorine atom bonded directly to a stereogenic center have been utilized in studies of enzyme mechanisms and as intermediates in asymmetric syntheses. The development of effective methodologies for the preparation of new selectively fluorinated, stereochemically defined compounds is critical to further advances of fluorine chemistry. The catalytic enantioselective construction of fluorinated stereogenic centers is still important challenge in modern organic chemistry

  13. Asymmetric transfer hydrogenation of ketones in aqueous solution catalyzed by Rhodium(III) complexes with C2-symmetric fluorene-ligands containing chiral (1R,2R)-cyclohexane-1,2-diamine

    Energy Technology Data Exchange (ETDEWEB)

    Montalvo-Gonzalez, Ruben [Universidad Autonoma de Nayarit, Tepic, Nay (Mexico). Unidad Academica de Ciencias Quimico Biologicas y Farmaceuticas; Chavez, Daniel; Aguirre, Gerardo; Parra-Hake, Miguel; Somanathan, Ratnasamy, E-mail: somanatha@sundown.sdsu.ed [Instituto Tecnologico de Tijuana, B.C. (Mexico). Centro de Graduados e Investigacion

    2010-07-01

    Two C{sub 2}-symmetric bis(sulfonamide) ligands containing fluorene-chiral (1R, 2R)-cyclohexane-1,2-diamine were complexed to Rh{sup III}(Cp{sup *}) and used as catalyst to reduce aromatic ketones. The corresponding chiral secondary alcohols were obtained in 87-100% ee and 85-99% yield, under asymmetric transfer hydrogenation (ATH) conditions using aqueous sodium formate as the hydride source. With acetophenone, 94% ee and 86-97% yield was achieved with substrate/catalyst (S/C) ratio of 10,000. (author)

  14. 'Americium(III)/trivalent lanthanides' separation using organothiophosphinic acids

    International Nuclear Information System (INIS)

    The present paper describes the extraction of neodymium and other lanthanides by saponified Cyanex 301 acid. The saponification of commercial Cyanex 301 acid favoured the extraction of macro concentrations of neodymium from sodium nitrate aqueous solutions (pHeq ∼ 4). The amount of lanthanide extracted in the organic phase always reached the third of the initial concentration of saponified Cyanex 301 acid, which assumed a cation exchange mechanism to occur during the extraction. No nitrate anion took part in the complex formation. This paper also compares the abilities of purified Cyanex 301, Cyanex 302 and Cyanex 272 acids to extract and separate 241Am(III) from 152Eu(III). Very high separation factors S.F.Am/Eu were observed in the case of purified Cyanex 301 acid. Finally some studies are presented herein using tri-n-butylphosphate (TBP) as a synergistic extractant with Cyanex 301 acid to separate actinides from trivalent lanthanide. (author)

  15. A racemic and enantiopure unsymmetric diiron(III) complex with a chiral o-carborane-based pyridylalcohol ligand: combined chiroptical, magnetic, and nonlinear optical properties.

    Science.gov (United States)

    Di Salvo, Florencia; Tsang, Min Ying; Teixidor, Francesc; Viñas, Clara; Planas, José Giner; Crassous, Jeanne; Vanthuyne, Nicolas; Aliaga-Alcalde, Núria; Ruiz, Eliseo; Coquerel, Gerard; Clevers, Simon; Dupray, Valerie; Choquesillo-Lazarte, Duane; Light, Mark E; Hursthouse, Michael B

    2014-01-20

    The design of molecule-based systems combining magnetic, chiroptical and second-order optical nonlinear properties is still very rare. We report an unusually unsymmetric diiron(III) complex 1, in which three bulky chiral carboranylpyridinealkoxide ligands (oCBhmp(-)) bridge both metal ions and the complex shows the above-mentioned properties. The introduction of o-carborane into the 2-(hydroxymethyl)pyridine (hmpH) architecture significantly alters the coordination of the simple or aryl-substituted 2-hmpH. The unusual architecture observed in 1 seems to be triggered by the poor nucleophilicity of our alkoxide ligand (oCBhmp(-)). A very rare case of spontaneous resolution takes place on precipitation or exposure to solvent vapor for the bulk compound, as confirmed by a combination of single-crystal and powder X-ray diffraction, second-harmonic generation, and circular dichroism. The corresponding enantiopure complexes (+)1 and (-)1 have also been synthesized and fully characterized. This research provides a new building block with unique geometry and electronics to construct coordination complexes with multifunctional properties. PMID:24338928

  16. Punctuated Chirality

    OpenAIRE

    Gleiser, Marcelo; Thorarinson, Joel; Walker, Sara Imari

    2008-01-01

    Most biomolecules occur in mirror, or chiral, images of each other. However, life is homochiral: proteins contain almost exclusively levorotatory (L) amino acids, while only dextrorotatory (R) sugars appear in RNA and DNA. The mechanism behind this fundamental asymmetry of life remains an open problem. Coupling the spatiotemporal evolution of a general autocatalytic polymerization reaction network to external environmental effects, we show through a detailed statistical analysis that high int...

  17. De novo design, synthesis and spectroscopic characterization of chiral benzimidazole-derived amino acid Zn(II) complexes: Development of tryptophan-derived specific hydrolytic DNA artificial nuclease agent

    Science.gov (United States)

    Parveen, Shazia; Arjmand, Farukh

    2012-01-01

    Novel ternary dizinc(II) complexes 1- 3, derived from 1,2-bis(1H-benzimidazol-2-yl)ethane-1,2-diol and L-form of amino acids (viz., tryptophan, leucine and valine) were synthesized and characterized by spectroscopic (IR, 1H NMR, UV-vis, ESI-MS) and other analytical methods. To evaluate the biological preference of chiral drugs for inherently chiral target DNA, interaction of 1- 3 with calf thymus DNA in Tris-HCl buffer was studied by various biophysical techniques which reveal that all these complexes bind to CT DNA non-covalently via electrostatic interaction. The higher Kb value of L-tryptophan complex 1 suggested greater DNA binding propensity. Further, to evaluate the mode of action at the molecular level, interaction studies of complexes 1 and 2 with nucleotides (5'-GMP and 5'-TMP) were carried out by UV-vis titrations, 1H and 31P NMR which implicates the preferential selectivity of these complexes to N3 of thymine rather than N7 of guanine. Furthermore, complex 1 exhibits efficient DNA cleavage with supercoiled pBR322. The complex 1 cleaves DNA efficiently involving hydrolytic cleavage pathway. Such chiral synthetic hydrolytic nucleases with asymmetric centers are gaining considerable attention owing to their importance in biotechnology and drug design, in particular to cleave DNA with sequence selectivity different from that of the natural enzymes.

  18. Chiral streamers

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Dandan; Cao, Xin [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Lu, Xinpei, E-mail: luxinpei@hotmail.com [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China); Ostrikov, Kostya [School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, Queensland 4000 (Australia); Comonwealth Scientific and Industrial Research Organization, P.O. Box 218, Sydney, New South Wales 2070 (Australia)

    2015-10-15

    The interaction of time-varying electromagnetic fields and solid, liquid, and gaseous matter may lead to electrical breakdown phenomena through the excitation of ionization waves or streamers that control the dynamics of localized plasma propagation through the media. The streamers usually propagate along straight lines, either between random points in space or along a certain direction in a guided mode. Here, we report on a new type of plasma discharges with the regular helical propagation pattern driven by a pulsed dc voltage in nitrogen at sub-atmospheric-pressure conditions. The helical guided streamers, named chiral streamers or chi-streamers, are excited without any external magnetic fields, which commonly cause helical plasma motions. We also demonstrate a hybrid propagation mode involving the interchangeable chiral streamers and the straight-line propagating plasmas. High-speed, time-resolved optical imaging reveals that the chiral streamers and the hybrid patterns are made of spatially localized discrete plasma bullets, similar to the straight-line guided streamers. These results may enable effective control of propagation of confined plasmas and electromagnetic energy along pre-determined, potentially deterministic paths, which have important implications for the development of next-generation plasma-based radiation sources, communication devices, and medical treatments.

  19. Chiral streamers

    Science.gov (United States)

    Zou, Dandan; Cao, Xin; Lu, Xinpei; Ostrikov, Kostya Ken

    2015-10-01

    The interaction of time-varying electromagnetic fields and solid, liquid, and gaseous matter may lead to electrical breakdown phenomena through the excitation of ionization waves or streamers that control the dynamics of localized plasma propagation through the media. The streamers usually propagate along straight lines, either between random points in space or along a certain direction in a guided mode. Here, we report on a new type of plasma discharges with the regular helical propagation pattern driven by a pulsed dc voltage in nitrogen at sub-atmospheric-pressure conditions. The helical guided streamers, named chiral streamers or chi-streamers, are excited without any external magnetic fields, which commonly cause helical plasma motions. We also demonstrate a hybrid propagation mode involving the interchangeable chiral streamers and the straight-line propagating plasmas. High-speed, time-resolved optical imaging reveals that the chiral streamers and the hybrid patterns are made of spatially localized discrete plasma bullets, similar to the straight-line guided streamers. These results may enable effective control of propagation of confined plasmas and electromagnetic energy along pre-determined, potentially deterministic paths, which have important implications for the development of next-generation plasma-based radiation sources, communication devices, and medical treatments.

  20. Use of lanthanide catalysts in air electrodes

    International Nuclear Information System (INIS)

    A review on the lanthanide catalysts suitable for the reduction catalysis of oxygen in air electrodes is presented. The kinds of lanthanide indicated to be used as catalysts of oxygen reduction are shown. (A.R.H.)

  1. Molecular modeling on the recognition of DNA sequence and conformational repair of sheared DNA by novel chiral metal complex D, L-[Co(phen)2hpip]3+

    Institute of Scientific and Technical Information of China (English)

    WU; Yanbo; ZHANG; Cuiping

    2006-01-01

    A study on the recognition of DNA sequence and conformational repair of sheared DNA by Novel Chiral Metal complex D,L-[Co(phen)2hpip]3+ (phen=1,10 phenanthroline, hpip=2-[2-hydroxyphenyl] imidazole [4,5-f][1,10] phenanthroline) is carried out with molecular simulations. The results reveal that two isomers of the complex could both recognize the normal DNA in the minor groove orientation, while recognize the sheared DNA in the major groove orientation and both isomers could convert the conformation of mismatched bases from sheared form to parallel form. Further analysis shows that the steric details of complex's intercalation to base stack determine the results of recognition, which is induced by the steric collision among ancillary ligand phen, bases and DNA backbone, and by the steric crowding occurring in the process of structural expansion of bases and DNA backbone. Detailed analysis reveals that the conformational repair of mismatched bases relates not only to the steric interactions, but also to the π-π stack among normal bases, mismatched bases and hpip ligand.

  2. Extraction of lanthanides with lipophilic crown ether carboxylic acids for neutron activation analysis

    International Nuclear Information System (INIS)

    Sym-dibenzo-16-crown-5-oxyacetic acid (I) and its modified analogues (II) and (III) were applied to the extraction of the lanthanides in solutions with high ionic strength and complex matrices. Increasing the length of the side arm alkyl group increases the lipophilicity of the crown ether carboxylic acids and enhances the distribution ratio of the lanthanide-macrocycle complexes in the organic phase. Three lanthanides, La, Eu, and Lu, in natural waters were analyzed by extraction with 2-(sym-dibenzo-16-crown-5-oxy)-steraric acid followed by neutron activation analysis (NAA). The extraction method combined with NAA is capable of detecting the lanthanides at 10-4 μg/L level in complex aqueous systems

  3. The Lanthanide Contraction beyond Coordination Chemistry.

    Science.gov (United States)

    Ferru, Geoffroy; Reinhart, Benjamin; Bera, Mrinal K; Olvera de la Cruz, Monica; Qiao, Baofu; Ellis, Ross J

    2016-05-10

    The lanthanide contraction is conceptualized traditionally through coordination chemistry. Here we break this mold in a structural study of lanthanide ions dissolved in an amphiphilic liquid. The lanthanide contraction perturbs the weak interactions between molecular aggregates that drive mesoscale assembly and emergent behavior. The weak interactions correlate with lanthanide ion transport properties, suggesting new strategies for rare-earth separation that exploit forces outside of the coordination sphere. PMID:27060294

  4. Separation of lanthanides through hydroxyapatite; Separacion de lantanidos mediante hidroxiapatita

    Energy Technology Data Exchange (ETDEWEB)

    Garcia M, F.G

    2006-07-01

    With the objective of obtaining from an independent way to each one of the lanthanides {sup 151} Pm, {sup 161} Tb, {sup 166} Ho and {sup 177} Lu free of carrier and with high specific activities starting from the indirect irradiation via, it intends in this work to determine the viability of separation of the couples Nd/Pm, Dy/Ho, Gd/Tb and Yb/Lu, by means of ion exchange column chromatography, using hydroxyapatite (HAp) and fluorite like absorbent material in complexing media. It is important to mention that have registered separation studies among lanthanides of the heavy group with those of the slight group, using the same mass and, in comparison with this work, quantities different from the father were used and of the son, also, that the separation studies were carried out among neighboring lanthanides. In this investigation, it was determined the effect that its have the complexing media: KSCN, sodium tartrate, sodium citrate, EDTA and aluminon, their pH and concentration, in the adsorption of the lanthanides in both minerals, in order to determine the chromatographic conditions for separation of the couples Nd/Pm, Dy/Ho, Gd/Tb and Yb/Lu. The work consists of five chapters, in the first one they are presented a theoretical introduction of the characteristics more important of the lanthanides, the hydroxyapatite and the fluorite; in the second, it is deepened in the ion exchange, as well as the two techniques (XRD and High Vacuum Electron Microscopy) to make the characterization of LnCI{sub 3} (Ln = Nd, Gd, Dy or Yb) synthesized. The third chapter, it describes the methodology continued in our experimental work; in the room, its are presented the obtained results of the static and dynamic method to determine the viability of separation of neighboring lanthanides; and finally, the five chapter shows the conclusions. In this study, it is concludes that the separation among neighboring lanthanides cannot be carried out in the minerals and used media; because

  5. Chiral geometry in multiple chiral doublet bands

    CERN Document Server

    Zhang, Hao

    2015-01-01

    The chiral geometry of the multiple chiral doublet bands with identical configuration is discussed for different triaxial deformation parameters $\\gamma$ in the particle rotor model with $\\pi h_{11/2}\\otimes \

  6. X-Ray Structure of 8-Quinolinolato Lanthanide Complex:(8-Quinolinolato) bis (2,6-di-tert-butyl-4-methylphenoxo) samarium

    Institute of Scientific and Technical Information of China (English)

    YUAN,Fu-Gen(袁福根); LIU,Qing-Sheng(刘青生); WENG,Lin-Hong(翁林红)

    2002-01-01

    The heteroleptic (8-quinolinolato)bis(2,6-di-tert-butyl-4-methylphenoxo) samarium complex was synthesized and characterized by elemental analysis, IR spectrun and X-ray diffraction analysis. The complex is a five-coordinate dimer. Each 8-quinolinolato oxygen atom links two samarium atoms as a bridge and the Sm-N bond is a typical donor bond.

  7. Thermal decompositions of heavy lanthanide aconitates

    International Nuclear Information System (INIS)

    The conditions of thermal decomposition of Tb(III), Dy, Ho, Er, Tm, Yb and Lu aconitates have been studied. On heating, the aconitates of heavy lanthanides lose crystallization water to yield anhydrous salts, which are then transformed into oxides. The aconitate of Tb(III) decomposes in two stages. First, the complex undergoes dehydration to form the anhydrous salt, which next decomposes directly to Tb4O7. The aconitates of Dy, Ho, Er, Tm, Yb and Lu decompose in three stages. On heating, the hydrated complexes lose crystallization water, yielding the anhydrous complexes; these subsequently decompose to Ln2O3 with intermediate formation of Ln2O2CO3. (author)

  8. Lanthanides: New life metals?

    Science.gov (United States)

    Chistoserdova, Ludmila

    2016-08-01

    Lanthanides (Ln(3+)) that are Rare Earth Elements, until recently thought to be biologically inert, have recently emerged as essential metals for activity and expression of a special type of methanol dehydrogenase, XoxF. As XoxF enzyme homologs are encoded in a wide variety of microbes, including microbes active in important environmental processes such as methane and methanol metabolism, Ln(3+) may represent some of the key biogeochemical drivers in cycling of carbon and other elements. However, significant gaps in understanding the role of Ln(3+) in biological systems remain as the functions of most of the proteins potentially dependent of Ln(3+) and their roles in specific metabolic networks/respective biogeochemical cycles remain unknown. Moreover, enzymes dependent on Ln(3+) but not related to XoxF enzymes may exist, and these so far have not been recognized. Through connecting the recently uncovered genetic divergence and phylogenetic distribution of XoxF-like enzymes and through elucidation of their activities, metal and substrate specificities, along with the biological contexts of respective biochemical pathways, most parsimonious scenarios for their evolution could be uncovered. Generation of such data will firmly establish the role of Ln(3+) in the biochemistry of Life inhabiting this planet. PMID:27357406

  9. The separation of lanthanides and actinides in supercritical fluid carbon dioxide

    International Nuclear Information System (INIS)

    Supercritical fluid carbon dioxide presents an attractive alternative to conventional solvents for recovery of the actinides and lanthanides. Carbon dioxide is a good solvent for fluorine and phosphate-containing ligands, including the traditional tributylphosphate ligand used in process-scale uranium separations. Actinide and lanthanide oxides may even be directly dissolved in carbon dioxide containing the complexes formed between these ligands and mineral acids, obviating the need for large volumes of acids for leaching and dissolution, and the corresponding organic liquid-liquid solvent extraction solutions. Examples of the application of this novel technology for actinide and lanthanide separations are presented. (author)

  10. Complexation of trivalent cationic lanthanides by N.O donor ligands: physico-chemical studies of the association and selectivity in solution

    International Nuclear Information System (INIS)

    The aim of this work is to study the complexation of f-elements in solution by ligands incorporating N-heterocyclic donors. These ligands display interesting properties for the selective separation of An(III)/Ln(III) have been studied to obtain a better understanding of the coordination properties with f-elements and to develop more selective extractants. The hepta-dentate ligand tpaam shows an affinity for Ln(III) similar to the tetradentate ligand tpa in water even when the three additional amide groups are bonded to the metal. Even though the complexation with tpa is exothermic, that with tpaam is endothermic with a more positive entropy. The dehydration of the cation disfavours the formation of Ln(III) complexes with ligands containing weak donors. The analysis of the solution paramagnetic relaxation times of the tpaam complexes is in agreement with data in the solid-state. There is little difference between the formation constants of the Ln3+ complexes with different ligands (tpaam, tpzen, tpa and tpza) as determined by UV-vis spectrophotometry in anhydrous acetonitrile. The limitations encountered during this study are intrinsic to the ligands studied. The preliminary study of two tetrapodal ligands containing acid and pyridine groups (Lpy)or pyrazine (Lpz) show the formation of 1:1 complexes in water. Analysis of the formation constants of the corresponding Gd(III) complexes shows that replacement of a pyridine group by pyrazine result in a loss of stability of 1.6 logarithmic units. (author)

  11. Preparation, properties, spectral (IR, electronic, FAB-MS and PXRD) and magnetic characterization of some lanthanide complexes containing tridentate thiosemicarbazone ligand

    International Nuclear Information System (INIS)

    Schiff bases, containing 'S' donor atom, such as benzophenonethiosemicarbazone (btscH), salicylidenethiosemicarbazone (stscH) and bis-salicylidenethiosemicarbazone (bstscH) have been reacted with methanolic solution of LnCl3.7H2O (Ln = LaIII and CeIII) followed by addition of the saturated solution of KOH (in EtOH) in different molar ratio(s), afforded a variety of lanthanum(III) chloride Schiff base complexes of the type, (Cl2Ln(L).4H2O) and (ClLn(L)2.3H2O) (where L = btscH, stscH, bstscH and Ln = LaIII and CeIII). These complexes have been characterized by elemental analysis, molar conductance, spectral (IR, UV-Visible and FAB-mass ) as well as magnetic studies. X-Ray powder diffraction on two of the complex was recorded on Rigaku Model D/Max-2200 PC using Cu-Kα, radiation (λ = 1.5406 Å). The crystallite size of the complexes (ClLa(bstsc)2.3H2O) (6) and (ClCe(bstsc)2.3H2O) (12) were found to be 280 and 191 Å respectively. On the basis of these physico-chemical data a tentative structure for these complexes have been proposed. These complexes were found to be solid and were soluble in Lewis bases such as in DMF and DMSO or pyridine. (author)

  12. Lanthanides separation by counter - current electrophoretic using α - hydroxyisobutyric acid

    International Nuclear Information System (INIS)

    Studies about counter-current electrophoretic separation of rare earth metal ions using α-hydroxyisobutyric acid as complexing electrolyte are discussed. La, Pr, Nd, Sm and Eu were separated and fractions with purities better than 99,9% were obtained, using neutron activation analysis. A relation between the first stability constant of the α-hydroxyisobutyrate/lanthanide complexes and their migration velocities were observed. (M.J.C.)

  13. The interactions between the sterically demanding trimesitylphosphine oxide and trimesityphosphine with scandium and selected lanthanide ions

    Science.gov (United States)

    Platt, Andrew W. G.; Singh, Kuldip

    2016-05-01

    The reactions between lanthanide nitrates, Ln(NO3)3 and scandium and lanthanide trifluoromethane sulfonates, Ln(Tf)3 with trimesitylphosphine oxide, Mes3PO show that coordination to the metal ions does not lead to crystalline complexes. Investigation of the reactions by 31-P NMR spectroscopy shows that weak complexes are formed in solution. The crystal structures of Mes3PO·0.5CH3CN (1) and [Mes3PO]3H3O·2CH3CN·Tf (2), formed in the reaction between ScTf3 and Mes3PO, are reported. Trimesitylphosphine, Mes3P, is protonated by scandium and lanthanide trifluoromethane sulfonates and lanthanide nitrates in CD3CN and the structure of [Mes3PH]Cl·HCl·2H2O (3) is reported.

  14. Structures and magnetic properties of several phenoxo-O bridged dinuclear lanthanide complexes: Dy derivatives displaying substituent dependent magnetic relaxation behavior.

    Science.gov (United States)

    Wang, Wen-Min; Qiao, Wan-Zhen; Zhang, Hong-Xia; Wang, Shi-Yu; Nie, Yao-Yao; Chen, Hong-Man; Liu, Zhen; Gao, Hong-Ling; Cui, Jian-Zhong; Zhao, Bin

    2016-05-10

    Nine dinuclear Ln(iii) complexes, [Ln(dbm)2(L)]2 (Ln = Eu (), Tb (), Dy (), Ho (), Er ()) and [Ln(dbm)2(L')]2 (Ln = Tb (), Dy (), Ho (), Er ()) (dbm = 1,3-diphenyl-1,3-propanedione, HL = 2-[[(4-methoxy-phenyl)imino]methyl]-8-hydroxy-quinoline and HL' = 2-[[(4-ethoxyphenyl)imino]methyl]-8-hydroxyquinoline) have been synthesized, and structurally and magnetically characterized. The nine complexes are all phenoxo-O bridged binuclear complexes, in which Ln1 and Ln1a are in an eight-coordinated environment bridged by two phenoxido oxygen atoms of two 8-hydroxyquinoline Schiff base ligands. Although complexes and have very similar structures, magnetic studies reveal that they exhibit different magnetic relaxation behaviors with the effective barriers (ΔE/kB) of 34.5 K for and 67.6 K for . The dissimilar dynamic magnetic behaviors of and mostly result from the different electron-donating effect induced by the two alkoxy (-OCH3 and -OC2H5) of the 8-hydroxyquinoline Schiff base ligands. Meanwhile, for complexes , , and , there are no observed magnetic relaxation behaviors under a zero dc field. In addition, the luminescence properties of , and were studied. PMID:27095548

  15. The structure and spectroscopy of lanthanide(III) complexes with picolinic acid N-oxide in solution and in the solid state

    International Nuclear Information System (INIS)

    The spectroscopic characteristics and the crystal structure of Eu(III) complex with picolinic acid N-oxide ligand, picNO, at room and liquid-nitrogen temperatures are discussed. Studies concerning the Eu(III) ion luminescence (intensity, luminescence lifetime measurements, and excitation spectra of the 5D0 → 7F0 transition) are presented. The selective excitation luminescence spectroscopy of Eu(III) in the range of the 5D0 → 7F0 transition is used for the study of Eu/picNO complexes in solution equilibria. In the crystal the complex molecules build the two-dimensional structures with additional Na+ cations and water molecules. This structure consists of edge-sharing chains of Na distorted octahedral, interconnected by Eu polyhedra (distorted square antiprisms). The ligand, pyridine-2-carboxylate-1-oxide, coordinates to the Eu(III) ion as an ionic bidentate chelate, forming the Na[Eu(picNO)4] complex of six-membered chelate rings with the bite angles of ca. 70.5 deg. The complex is symmetrical; the Eu(III) ion is eight-coordinated

  16. Synthesis of novel lanthanide acylpyrazolonato ligands with long aliphatic chains and immobilization of the Tb complex on the surface of silica pre-modified via hydrophobic interactions.

    Science.gov (United States)

    Pettinari, C; Marchetti, F; Pettinari, R; Belousov, Y A; Taydakov, I V; Krasnobrov, V D; Petukhov, D I; Drozdov, A A

    2015-09-01

    Five new complexes Ln(Q(C17))3(H2O)(Solv) (Ln = Y, Solv = H2O, Ln = Tb, Dy, Sm or Eu, Solv = EtOH) were synthesized with the acylpyrazolonato ligand Q(C17) bearing a long aliphatic C17H35 chain in the acyl moiety, and the crystal structure of Y(Q(C17))3(H2O)2 shows the three aliphatic chains from the coordinated ligands positioned in the same direction, affording plane layers built by Y(Q(C17))3(H2O)2 molecules connected through H-bonding interactions. The layers are stitched to each other like in "hook & loop" tapes. Luminescence of complexes was determined and the complex Tb(Q(C17))3(H2O)(EtOH) was immobilized on the surface of silica preprocessed using a C17H35CONH(CH2)3Si(OEt)3 reagent via hydrophobic interactions of long aliphatic chains. Luminescent properties and micromorphology of the obtained hybrid particles and hybrid films were investigated. Intensive green emission of the complex retains after grafting onto the silica surface. Inclusion of the complex on the surface of silica materials occurs as separate molecules, after the disruption of the H-bonding network present in the crystalline phase of the pure terbium sample. PMID:26225470

  17. Sequential separation of actinides and lanthanides by extraction chromatography using a CMPO-TBP/XAD7 column

    International Nuclear Information System (INIS)

    CMPO/TBP sorbed on Amberlite XAD7 resin was used for the separation of actinides and lanthanides from nitric acid solutions by extraction chromatography. The distribution ratios of actinides and lanthanide fission products (Ce, Eu) as a function of acid concentration and some complexing agents were determined. In strong HNO3 medium (> 1 mol/l) the tri-, tetra- and hexavalent actinides as well as the lanthanides have shown great affinity for the CMPO/TBP/XAD7 sorbent. The same behavior was found in HCl medium except for trivalent actinides and lanthanides which show lower distribution values in the same acid range. The effect of some complexing agents as DTPA and ammonium oxalate were also investigated. In DTPA only hexavalent actinides showed higher distribution value. On the basis of these differences, an alternative procedure for actinide-lanthanide separation and actinides from each other is proposed. (author)

  18. Chiral symmetry and chiral-symmetry breaking

    International Nuclear Information System (INIS)

    These lectures concern the dynamics of fermions in strong interaction with gauge fields. Systems of fermions coupled by gauge forces have a very rich structure of global symmetries, which are called chiral symmetries. These lectures will focus on the realization of chiral symmetries and the causes and consequences of thier spontaneous breaking. A brief introduction to the basic formalism and concepts of chiral symmetry breaking is given, then some explicit calculations of chiral symmetry breaking in gauge theories are given, treating first parity-invariant and then chiral models. These calculations are meant to be illustrative rather than accurate; they make use of unjustified mathematical approximations which serve to make the physics more clear. Some formal constraints on chiral symmetry breaking are discussed which illuminate and extend the results of our more explicit analysis. Finally, a brief review of the phenomenological theory of chiral symmetry breaking is presented, and some applications of this theory to problems in weak-interaction physics are discussed

  19. DAE-BRNS symposium on spectroscopy of lanthanides and actinides (SLA-99)

    International Nuclear Information System (INIS)

    Spectroscopy of lanthanides and actinides, due to the rich and complex interactions of the f electrons, is of immense interest to basic sciences and technology. This volume covers both basic and applied aspects of the spectroscopy of lanthanides and actinides and also include the recent developments and emerging areas. The papers have been classified in several broad categories namely theoretical studies, high resolution spectroscopy, laser spectroscopy, solid state spectroscopy, analytical spectroscopy, optics and instrumentation and applications. Papers relevant to INIS are indexed separately

  20. Novel materials based on DNA-CTMA and lanthanide (Ce(3+) , Pr(3+) ).

    Science.gov (United States)

    Lazar, Cosmina Andreea; Kajzar, François; Mihaly, Maria; Rogozea, Adina Elena; Petcu, Adina Roxana; Olteanu, Nicoleta Liliana; Rau, Ileana

    2016-09-01

    New, deoxyribonucleic acid (DNA) based compounds, functionalized with hexadecyltrimethylammonium chloride (CTMA) and lanthanide hydroxide nanoparticles were synthesized. The spectral measurements suggest that between the DNA-CTMA complex and the lanthanide (III) ions a chemical interaction takes place. The obtained materials exhibit an improved fluorescence efficiency, showing a potential interest for application in photonics, and more particularly, in light emitting devices. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 613-617, 2016. PMID:27120012

  1. Chemical equilibria of lanthanides(Ln(III)=Pr, Sm, Gd, Dy)-macro-cyclic complexes with monodentate ligands in CH3OH(Part I)

    International Nuclear Information System (INIS)

    Ln-macrocyclic((20)DOTA) complexes, (Ln((20)DOTA)NO3)(H2O))(NO3)2·xH2O(Ln(III)=Pr, Sm, Gd, Dy), which had been synthesized from 2, 6-diformyl-p-cresol(DFPC), was placed in methanol for 2 days, and (Ln((20)DOTA)(NO3)(CH3OH))2+ was formed. The equilibrium constants(K) for the substitution of coordinated CH3OH in the Ln-(20)DOTA complexes by various auxiliary ligands, La(=monodentate ligands; pyridine, imidazole, triethylamine, diethylamine, piperidine) were determined spectroscopically at 25. deg. C and 0.1 M. The pKa of auxiliary ligand is in the order of pyridine < imidazole< triethylamine< diethylamine< piperidine, however the K has shown the trend of pyridine< imidazole< diethylamine< piperidine< triethylamine

  2. 3,2-HOPO Complexes of Near-Infra-Red (NIR) Emitting Lanthanides: Sensitization of Ho(III) and Pr(III) in Aqueous Solution

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Evan G.; Szigethy, Geza; Xu, Jide; Palsson, Lars-Olof; Beeby, Andrew; Raymond, Kenneth N.

    2008-05-19

    There is a growing interest in Near Infra-Red (NIR) emission originating from organic complexes of Ln{sup III} cations. As a major impetus, biological tissues are considerably more transparent at these low energy wavelengths when compared to visible radiation, which facilitates deeper penetration of incident and emitted light. Furthermore, the long luminescence lifetimes of Ln{sup III} complexes (eg. Yb{sup III}, {tau}{sub rad} {approx} 1 ms) when compared to typical organic molecules can be utilized to vastly improve signal to noise ratios by employing time-gating techniques. While the improved quantum yield of Yb{sub III} complexes when compared to other NIR emitters favors their use for bioimaging applications, there has also been significant interest in the sensitized emission from other 4f metals such as Ln = Nd, Ho, Pr and Er which have well recognized applications as solid state laser materials (eg. Nd {approx} 1.06 {micro}m, Ho {approx} 2.09 {micro}m), and in telecommunications (eg. Er {approx} 1.54 {micro}m) where they can be used for amplification of optical signals. As a result of their weak (Laporte forbidden) f-f absorptions, the direct excitation of Ln{sup III} cations is inefficient, and sensitization of the metal emission is more effectively achieved using the so-called antenna effect. We have previously examined the properties of several Eu{sup III} complexes which feature 1-hydroxypyridin-2-one (Fig. 1) as the light harvesting chromophore. While the 1,2-HOPO isomer was found to strongly sensitize Eu{sup III}, we noted the analogous Me-3,2-HOPO isomer does not, which prompted further investigation of the properties of this chromophore with other metals.

  3. Design and Synthesis of Chiral Zn2+ Complexes Mimicking Natural Aldolases for Catalytic C–C Bond Forming Reactions in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Susumu Itoh

    2014-01-01

    Full Text Available Extending carbon frameworks via a series of C–C bond forming reactions is essential for the synthesis of natural products, pharmaceutically active compounds, active agrochemical ingredients, and a variety of functional materials. The application of stereoselective C–C bond forming reactions to the one-pot synthesis of biorelevant compounds is now emerging as a challenging and powerful strategy for improving the efficiency of a chemical reaction, in which some of the reactants are subjected to successive chemical reactions in just one reactor. However, organic reactions are generally conducted in organic solvents, as many organic molecules, reagents, and intermediates are not stable or soluble in water. In contrast, enzymatic reactions in living systems proceed in aqueous solvents, as most of enzymes generally function only within a narrow range of temperature and pH and are not so stable in less polar organic environments, which makes it difficult to conduct chemoenzymatic reactions in organic solvents. In this review, we describe the design and synthesis of chiral metal complexes with Zn2+ ions as a catalytic factor that mimic aldolases in stereoselective C–C bond forming reactions, especially for enantioselective aldol reactions. Their application to chemoenzymatic reactions in aqueous solution is also presented.

  4. Chiral mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Plum, Eric, E-mail: erp@orc.soton.ac.uk [Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Zheludev, Nikolay I., E-mail: niz@orc.soton.ac.uk [Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637378 (Singapore)

    2015-06-01

    Mirrors are used in telescopes, microscopes, photo cameras, lasers, satellite dishes, and everywhere else, where redirection of electromagnetic radiation is required making them arguably the most important optical component. While conventional isotropic mirrors will reflect linear polarizations without change, the handedness of circularly polarized waves is reversed upon reflection. Here, we demonstrate a type of mirror reflecting one circular polarization without changing its handedness, while absorbing the other. The polarization-preserving mirror consists of a planar metasurface with a subwavelength pattern that cannot be superimposed with its mirror image without being lifted out of its plane, and a conventional mirror spaced by a fraction of the wavelength from the metasurface. Such mirrors enable circularly polarized lasers and Fabry-Pérot cavities with enhanced tunability, gyroscopic applications, polarization-sensitive detectors of electromagnetic waves, and can be used to enhance spectroscopies of chiral media.

  5. Two chiral mononuclear and one-dimensional cadmium(II) complexes constructed by (1R,2R)-N1,N2-bis(pyridinylmethyl)cyclohexane-1,2-diamine derivatives: Effect of positional isomerism

    Science.gov (United States)

    Cheng, Lin; Cao, Qing-Na; Zhang, Li-Min; Zhang, Xiu-Ying; Gou, Shao-Hua; Fang, Lei

    2013-02-01

    Reactions of (1R,2R)-N1,N2-bis(pyridinylmethyl)cyclohexane-1,2-diamine derivatives, (1R,2R)-2-bpcd and (1R,2R)-3-bpcd [(1R,2R)-2-bpcd = (1R,2R)-N1,N2-bis(pyridin-2-ylmethyl)cyclohexane-1,2-diamine, (1R,2R)-3-bpcd = (1R,2R)-N1,N2-bis(pyridin-3-ylmethyl)cyclohexane-1,2-diamine], with CdI2 in an analogous way led to the formation of a chiral discrete mononuclear complex and a chiral one-dimensional polymeric chain, respectively, which may be attributed to the positional isomerism of the ligands. The chiral organic ligands and complexes display luminescent properties indicating that they may have a potential application as optical materials. Powder second-harmonic generation (SHG) efficiency measurement shows that the SHG efficiency of the complexes is approximately 0.3 and 0.45 times that of KDP, respectively.

  6. Biological toxicity of lanthanide elements on algae.

    Science.gov (United States)

    Tai, Peidong; Zhao, Qing; Su, Dan; Li, Peijun; Stagnitti, Frank

    2010-08-01

    The biological toxicity of lanthanides on marine monocellular algae was investigated. The specific objective of this research was to establish the relationship between the abundance in the seawater of lanthanides and their biological toxicities on marine monocellular algae. The results showed that all single lanthanides had similar toxic effects on Skeletonema costatum. High concentrations of lanthanides (29.04+/-0.61 micromol L(-1)) resulted in 50% reduction in growth of algae compared to the controls (0 micromol L(-1)) after 96 h (96 h-EC50). The biological toxicity of 13 lanthanides on marine monocellular algae was unrelated with the abundance of different lanthanide elements in nature, and the "Harkins rule" was not appropriate for the lanthanides. A mixed solution that contained equivalent concentrations of each lanthanide element had the same inhibition effect on algae cells as each individual lanthanide element at the same total concentration. This phenomenon is unique compared to the groups of other elements in the periodic table. Hence, we speculate that the monocellular organisms might not be able to sufficiently differentiate between the almost chemically identical lanthanide elements. PMID:20547408

  7. Conformational and Coordination Equilibria on DOTA Complexes of Lanthanide Metal Ions in Aqueous Solution Studied by 1H-NMR Spectroscopy

    OpenAIRE

    Aime, Silvio; Botta, Mauro; Fasano, Mauro; Marques, M. Paula M.; Geraldes, Carlos F. G. C.; Pubanz, Dirk; Merbach, André E.

    1997-01-01

    A variable-temperature, -pressure, and -ionic strength 1H NMR study of the DOTA complexes of different trivalent cations (Sc, Y, La, Ce → Lu) (DOTA = 1,4,7,10-tetraaza-1,4,7,10-tetrakis(carboxymethyl)cyclododecane) yielded data that are in contradiction with the hitherto used model of only two enantiomeric pairs of diastereoisomers that differ in the ligand conformations. A two-isomer equilibrium cannot explain the newly observed apparent reversal of the isomer ratio at the end of the series....

  8. Water-soluble chiral metallopeptoids.

    Science.gov (United States)

    Baskin, Maria; Maayan, Galia

    2015-09-01

    Metal ions play a significant role in the activity of biological systems including catalysis, recognition and folding. Therefore, introducing metal ions into peptidomimetic oligomers is a potential way for creating biomimetic metal complexes toward applications in sensing, recognition, drug design and catalysis. Herein we report the design, synthesis and characterization of water-soluble chiral N-substituted glycine oligomers, "peptoids," with one and two distinct intramolecular binding sites for metal ions such as copper and cobalt. We demonstrate for the first time the incorporation of the chiral hydrophilic group (S)-(+)-1-methoxy-2-propylamine (Nsmp) within peptoid sequences, which provides both chirality and water solubility. Two peptoids, a heptamer, and a dodecamer bearing two and four 8-hydroxyquinoline (HQ) groups respectively as metal-binding ligands, were synthesized on solid support using the submonomer approach. Using UV-titrations and ESI-MS analysis we demonstrate the creation of a novel metallopeptoid bearing two metal ions in distinct binding sites via intramolecular chelation. Exciton couplet circular dichroism (ECCD) demonstrated chiral induction from the chiral non-helical peptoids to the metal centers. PMID:25969151

  9. Enhancement of lanthanide evaporation by complexation: Dysprosium tri-iodide mixed with indium iodide and thulium tri-iodide mixed with thallium iodide

    International Nuclear Information System (INIS)

    The vapors in equilibrium with condensates of DyI3, DyI3/InI, TmI3, and TmI3/TlI were observed over the temperature range from 900 K to 1400 K using x-ray induced fluorescence. The total densities of each element (Dy, Tm, In, Tl, and I) in the vapor, summed over all atomic and molecular species, were determined. Dramatic enhancements in the total vapor densities of Dy and Tm were observed in the vapors over DyI3/InI and TmI3/TlI as compared to the vapors over pure DyI3 and pure TmI3, respectively. An enhancement factor exceeding 10 was observed for Dy at T≈ 1020 K, decreasing to 0 at T≈ 1250 K. An enhancement factor exceeding 20 was observed for Tm at T≈ 1040 K, decreasing to 0 at T≈ 1300 K. Such enhancements are expected from the formation of the vapor-phase hetero-complexes DyInI4 and TmTlI4. Numerical simulations of the thermo-chemical equilibrium suggest the importance of additional complexes in liquid phases. A description of the measurement technique is given. Improvements in the absolute calibration lead to an approximately 40% correction to previously reported preliminary results [J. J. Curry et al., Chem. Phys. Lett. 507, 52 (2011); Appl. Phys. Lett. 100, 083505 (2012)

  10. LANTHANIDE ENHANCE LUMINESCENCE (LEL) WITH ONE AND TWO PHOTON EXCITATION OF QUANTUM DYES LANTHANIDE (III) - MACROCYCLES

    Science.gov (United States)

    Title: Lanthanide Enhance Luminescence (LEL) with one and two photon excitation of Quantum Dyes? Lanthanide(III)-Macrocycles Principal Author:Robert C. Leif, Newport InstrumentsSecondary Authors:Margie C. Becker, Phoenix Flow Systems Al Bromm, Virginia Commonw...

  11. Selectivity enhancement of Arsenazo(III) reagent towards heavier lanthanides using polyaminocarboxylic acids: A spectrophotometric study

    Science.gov (United States)

    Matharu, Komal; Mittal, Susheel K.; Ashok Kumar, S. K.; Sahoo, Suban K.

    2015-06-01

    A new study has been conducted to quantify lanthanide(III) ions using Arsenazo III-polyaminocarboxylic acid (PACA) system. The study disclosed two different analytically important information: (i) λmax of lanthanide-Arsenazo III complexes for lighter lanthanides like Ce(III) and Nd(III) did not shift from its original position on addition of PACA and (ii) for heavier lanthanides like Dy(III), Tm(III) and Lu(III) a new λmax at 538 nm was observed, while wavelengths at 610 nm and 654 nm were disappeared in presence of ethylenediaminetertracetic acid (EDTA) and trans-1,2-Diaminocyclohexane-N,N,N‧,N‧-tetraacetic acid (DCTA), further the intensity of peak decreased with increase in lanthanide(III) ion concentration. Effect of ethylene glycol-bis(2-aminoethylether)-N,N,N‧,N‧-tetraacetic acid (EGTA) and N-(2-hydroxyethyl) ethylenediamine-N,N‧,N‧-triacetic acid (EDTA-OH) on Arsenzo(III)-Ln(III) complex is very weak and there is no analytically importance of such interaction. Moreover, this work confirms that Nd(III) and heavy lanthanides can be successfully determined with high accuracy in the working range of concentration of these metal ions.

  12. An NMR strategy for fragment-based ligand screening utilizing a paramagnetic lanthanide probe

    International Nuclear Information System (INIS)

    A nuclear magnetic resonance-based ligand screening strategy utilizing a paramagnetic lanthanide probe is presented. By fixing a paramagnetic lanthanide ion to a target protein, a pseudo-contact shift (PCS) and a paramagnetic relaxation enhancement (PRE) can be observed for both the target protein and its bound ligand. Based on PRE and PCS information, the bound ligand is then screened from the compound library and the structure of the ligand–protein complex is determined. PRE is an isotropic paramagnetic effect observed within 30 Å from the lanthanide ion, and is utilized for the ligand screening in the present study. PCS is an anisotropic paramagnetic effect providing long-range (∼40 Å) distance and angular information on the observed nuclei relative to the paramagnetic lanthanide ion, and utilized for the structure determination of the ligand–protein complex. Since a two-point anchored lanthanide-binding peptide tag is utilized for fixing the lanthanide ion to the target protein, this screening method can be generally applied to non-metal-binding proteins. The usefulness of this strategy was demonstrated in the case of the growth factor receptor-bound protein 2 (Grb2) Src homology 2 (SH2) domain and its low- and high-affinity ligands.

  13. Chiral Gravitational Waves from Chiral Fermions

    CERN Document Server

    Anber, Mohamed M

    2016-01-01

    We report on a new mechanism that leads to the generation of primordial chiral gravitational waves, and hence, the violation of the parity symmetry in the Universe. We show that nonperturbative production of fermions with a definite helicity is accompanied by the generation of chiral gravitational waves. This is a generic and model-independent phenomenon that can occur during inflation, reheating and radiation eras, and can leave imprints in the cosmic microwave background polarization and may be observed in future ground- and space-based interferometers. We also discuss a specific model where chiral gravitational waves are generated via the production of light chiral fermions during pseudoscalar inflation.

  14. Monomeric Cu(Ⅱ) Complex Containing Chiral Phase-transfer Catalyst as Ligand and Its Asymmetrically Catalytic Reaction

    Institute of Scientific and Technical Information of China (English)

    QU Zhi-Rong; XIONG Ren-Gen

    2008-01-01

    The thermal treatment of CuCl2 with N-(4'-vinylbenzyl)cinchonidinitim chloride(L1)afforded a monomeric discrete homochiral copper(Ⅱ)complex N-4'-(vinylbenzyl)cinchonidinium trichlorocoprate(Ⅱ)(1).Their applications to the enantioselectively catalytic alkylation reaction of N-(diphenylmethylidene)glycine tert-butyl ester(3)show that the higher ee value observed in catalyst 1 than that in the corresponding free ligand L1 is probably due to the rigidity enhancement after the coordination of N atom of quinoline ring to the copper ion.

  15. The Absorption Spectra of Some Lanthanide (III Ions

    Directory of Open Access Journals (Sweden)

    Suresh Purohit

    2013-04-01

    Full Text Available Complexes of some lanthanides such as Pr (Praseodymium, Nd (Neodymium, Sm (Samarium and Tb (Terbium gives absorption bands in the visible region of the spectrum. The Pr(III, Nd(III, Sm(III and Tb(III ions have four, ten, seven and two peaks respectively in their absorption bands. On the other hand Gd (Gadolinium gives absorption band in UV- region and it has two peaks in its absorption band.

  16. Magnetic molecular materials with paramagnetic lanthanide ions

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The diverse magnetic properties of lanthanide-based magnetic molecular materials are introduced in the following organization.First,the general aspects of magnetic molecular materials and electronic states of lanthanide ions are introduced.Then the structures and magnetic properties are described and analyzed for molecules with one lanthanide ion,4f-4f,4f-3d and 4f-p magnetic coupling interactions.In each section,magnetic coupling,magnetic ordering and magnetic relaxation phenomenon are briefly reviewed using some examples.Finally,some possibilities of developing magnetic molecular materials containing lanthanide ions are discussed in the outlook part.

  17. Thermoemission properties of barium lanthanides

    International Nuclear Information System (INIS)

    The electron work function of Ba3Ln4O9 compounds in a Ln series from Sm to Ln, Y, Sc is measured by the method of thermoemission. Absence of periodicity in changing PHIsub(ef) is established which is in agreement with monotonous dependence of the other physicochemical properties on the ordinal number of Ln and is explained by the energy penetration of 4f-orbitals of lanthanide during the oxide formation

  18. Enrichment of lanthanides in aragonite

    Institute of Scientific and Technical Information of China (English)

    瞿成利; 路波; 刘刚

    2009-01-01

    Using the constant addition technique,the coprecipitation of lanthanum,gadolinium,and lutetium with aragonite in seawater was experimentally investigated at 25 ℃.Their concentrations in aragonite overgrowths were determined by inductive coupled plasma mass spectrometer.All these lanthanides were strongly enriched in aragonite overgrowths.The amount of lanthanum,gadolinium,and lutetium incorporated into aragonite accounted for 57%-99%,50%-89%,and 40%-91% of their initial total amount,respectively.With the in...

  19. Anomalous Chiral Superfluidity

    OpenAIRE

    Lublinsky, Michael(Physics Department, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel); Zahed, Ismail

    2009-01-01

    We discuss both the anomalous Cartan currents and the energy-momentum tensor in a left chiral theory with flavour anomalies as an effective theory for flavored chiral phonons in a chiral superfluid with the gauged Wess-Zumino-Witten term. In the mean-field (leading tadpole) approximation the anomalous Cartan currents and the energy momentum tensor take the form of constitutive currents in the chiral superfluid state. The pertinence of higher order corrections and the Adler-Bardeen theorem is ...

  20. Self-assembly of multinuclear coordination species with chiral bipyridine ligands: silver complexes of 5,6-CHIRAGEN(o,m,p-xylidene) ligands and equilibrium behaviour in solution.

    Science.gov (United States)

    Mamula, O; Monlien, F J; Porquet, A; Hopfgartner, G; Merbach, A E; von Zelewsky, A

    2001-01-19

    The complexation reactions between Ag- and a series of enantiopure ligands belonging to the CHIRAGEN (from CHIRAlity GENerator) family (L1, L2, L3, based on (-)-5,6-pinene bipyridine) have been studied in solution. It has been shown that the length of the bridge plays a fundamental role in the self-assembly processes leading to different compounds: mononuclear complexes (with L3), mixtures of polynuclear complexes (with L2) and circular helicates (with L 1). Although the absolute configuration of the chiral centres in all three ligands is the same, the metal-centred chirality of L3 (delta) is inverted with respect to that in the other two complexes with L1 and L2 (delta). The metal configuration is thus opposite in the mononuclear complex with respect to the polynuclear species. Detailed thermodynamic studies were carried out for the Ag+ and L1 ligand system by 1H and 109Ag NMR spectroscopy (as a function of concentration, temperature and pressure). At low temperature and high pressure, the [Ag6L1(6)]6+ hexanuclear circular helicate forms a tetranuclear circular helicate [Ag4L1(4)]4+: 2[Ag6L1(6)]6+ 3 [Ag4L1(4)]4+. The thermodynamics parameters, obtained by temperature and pressure variation, have the following values: K298 = (8.7 +/- 0.7) x 10(-5) mol x kg(-1), deltaHo = -15.65 +/- 0.8 kJ x mol(-1), deltaSo = -130.2 +/- 3 J x mol(-1) x K(-1) and deltaVo(256 K)= -160 +/- 12 cm3 x mol(-1). The reaction volume calculated according to Connolly's method indicates that the calculated structure of [Ag4L1(4)]4+ is plausible. Both the signs and large magnitudes of deltaSo and deltaVo are counterintuitive, yet can be understood by modelling methods. PMID:11271539

  1. Introduction to chiral symmetry

    International Nuclear Information System (INIS)

    These lectures are an attempt to a pedagogical introduction into the elementary concepts of chiral symmetry in nuclear physics. Effective chiral models such as the linear and nonlinear sigma model will be discussed as well as the essential ideas of chiral perturbation theory. Some applications to the physics of ultrarelativistic heavy ion collisions will be presented

  2. Lanthanide mixed ligand chelates for DNA profiling and latent fingerprint detection

    Science.gov (United States)

    Menzel, E. R.; Allred, Clay

    1997-02-01

    It is our aim to develop a universally applicable latent fingerprint detection method using lanthanide (rare-earth) complexes as a source of luminescence. Use of these lanthanide complexes offers advantages on several fronts, including benefits from large Stokes shifts, long luminescence lifetimes, narrow emissions, ability of sequential assembly of complexes, and chemical variability of the ligands. Proper exploitation of these advantages would lead to a latent fingerprint detection method superior to any currently available. These same characteristics also lend themselves to many of the problems associated with DNA processing in the forensic science context.

  3. Effect of complexation with lanthanide metal ions on the photochromism of (1,3,3-trimethyl-5′-hydroxy-6′-formyl- indoline-spiro2,2′-[2h]chromene in different media

    Directory of Open Access Journals (Sweden)

    Boris Lukyanov

    2006-03-01

    Full Text Available Complexation of lanthanide ions {Ln(III ions [Tb(III, Eu(III, or Sm(III]} with the spiropyran-derived merocyanine obtained in dark and under steady irradiation of indoline spiropyran (1,3,3-trimethyl-5′-hydroxy-6′-formyl-indoline-spiro-2,2′-[2H]chromene induces a noticeable hypsochromic shift of about 10–110 nm of its visible absorption band concomitant with hypochromic effect and influences its thermal bleaching in the dark. The effect of lanthanide ions and medium on photochromic, spectral-and-kinetic, and luminescence properties of the spiropyran and its complexes in solution and polymer matrix of polymethylmethacrylate (PMMA is studied. Efficient energy transfer from the spiropyran moiety results in efficient typical luminescence from the Ln(III ion that becomes more pronounced in polar nonalcoholic solvents and PMMA solid matrix. Moreover, luminescence mappings for pattern recognition analysis have been obtained from which the nature of the solvent and/or the ligand is clearly identified.

  4. Coordination chemistry of several radius-sensitive complexones and applications to lanthanide-actinide separations

    International Nuclear Information System (INIS)

    The relationships between the lanthanide complex formation equilibria and the lanthanide-actinide separation application of three radius sensitive ligands have been studied. The consecutive stepwise formation constants of the 1:1, 2:1, and 3:1 chelate species formed by the interaction of DHDMB and the tripositive lanthanides and yttrium were determined potentiometrically at 0.1 M ionic strength and 250C. Results indicate that three different coordination modes, one tridentate and two bidentate are in evidence. Tracer level 241Am - 155Eu cation-exchange experiments utilizing DHDMB eluents indicate that this dihydroxycarboxylate does not form a sufficiently strong americium complex to elute that actinide ahead of europium. The overall stability of the americium 3:1 complex appears intermediate between samarium and europium. Cation-exchange elutions of 241Am, 155Eu, and 160Tb mixtures with EEDTA solutions prove that the EEDTA ligand is capable of eluting americium ahead of all of the tripositive lanthanide cations. The minimum separation occurs with terbium, where the Am-Tb separation factor is 1.71. 1,5-diaminopentane-N,N,N',N'-tetraacetic acid (PMDTA) was synthesized using cation exchange. A mathematical method was developed for the formation constants of the protonated and unprotonated lanthanide-PMDTA complexes from potentiometry. Cation-exchange elutions of tracer quantities of Am, Eu, and Tb revealed that terbium is eluted ahead of both americium and europium

  5. Speciation and gene flow between snails of opposite chirality.

    Directory of Open Access Journals (Sweden)

    Angus Davison

    2005-09-01

    Full Text Available Left-right asymmetry in snails is intriguing because individuals of opposite chirality are either unable to mate or can only mate with difficulty, so could be reproductively isolated from each other. We have therefore investigated chiral evolution in the Japanese land snail genus Euhadra to understand whether changes in chirality have promoted speciation. In particular, we aimed to understand the effect of the maternal inheritance of chirality on reproductive isolation and gene flow. We found that the mitochondrial DNA phylogeny of Euhadra is consistent with a single, relatively ancient evolution of sinistral species and suggests either recent "single-gene speciation" or gene flow between chiral morphs that are unable to mate. To clarify the conditions under which new chiral morphs might evolve and whether single-gene speciation can occur, we developed a mathematical model that is relevant to any maternal-effect gene. The model shows that reproductive character displacement can promote the evolution of new chiral morphs, tending to counteract the positive frequency-dependent selection that would otherwise drive the more common chiral morph to fixation. This therefore suggests a general mechanism as to how chiral variation arises in snails. In populations that contain both chiral morphs, two different situations are then possible. In the first, gene flow is substantial between morphs even without interchiral mating, because of the maternal inheritance of chirality. In the second, reproductive isolation is possible but unstable, and will also lead to gene flow if intrachiral matings occasionally produce offspring with the opposite chirality. Together, the results imply that speciation by chiral reversal is only meaningful in the context of a complex biogeographical process, and so must usually involve other factors. In order to understand the roles of reproductive character displacement and gene flow in the chiral evolution of Euhadra, it will be

  6. Insights on some chiral smectic phases

    Indian Academy of Sciences (India)

    B Pansu

    2003-08-01

    Combining layered positional order as smectic order and chirality can generate complex architectures since twist parallel to the layers is not allowed. This paper will review some new experimental results on different phases resulting from the competition between smectic positional order and twist orientational order. It concerns the TGBA and the NL*, that is the liquid line phase as well as the SmQ phase. Chiral effects in the isotropic phase will also be discussed.

  7. A TRUEX-based separation of americium from the lanthanides

    Energy Technology Data Exchange (ETDEWEB)

    Bruce J. Mincher; Nicholas C. Schmitt; Mary E. Case

    2011-03-01

    Abstract: The inextractability of the actinide AnO2+ ions in the TRUEX process suggests the possibility of a separation of americium from the lanthanides using oxidation to Am(V). The only current method for the direct oxidation of americium to Am(V) in strongly acidic media is with sodium bismuthate. We prepared Am(V) over a wide range of nitric acid concentrations and investigated its solvent extraction behavior for comparison to europium. While a separation is achievable in principal, the presence of macro amounts of cerium competes for the sparingly soluble oxidant and the oxidant itself competes for CMPO complexation. These factors conspire to reduce the Eu/Am separation factor from ~40 using tracer solutions to ~5 for extractions from first cycle raffinate simulant solution. To separate pentavalent americium directly from the lanthanides using the TRUEX process, an alternative oxidizing agent will be necessary.

  8. Advancing the scientific basis of trivalent actinide-lanthanide separations

    International Nuclear Information System (INIS)

    For advanced fuel cycles designed to support transmutation of transplutonium actinides, several options have been demonstrated for process-scale aqueous separations for U, Np, Pu management and for partitioning of trivalent actinides and fission product lanthanides away from other fission products. The more difficult mutual separation of Am/Cm from La-Tb remains the subject of considerable fundamental and applied research. The chemical separations literature teaches that the most productive alternatives to pursue are those based on ligand donor atoms less electronegative than O, specifically N- and S-containing complexants and chloride ion (Cl-). These 'soft-donor' atoms have exhibited usable selectivity in their bonding interactions with trivalent actinides relative to lanthanides. In this report, selected features of soft donor reagent design, characterization and application development will be discussed. The roles of thiocyanate, aminopoly-carboxylic acids and lactate in separation processes are detailed. (authors)

  9. Solvent extraction studies of lanthanide acetylacetonates. Part 3

    International Nuclear Information System (INIS)

    The complex formation of the heavier trivalent lanthanides (Ln) 65Tb, 67Ho, 69Tm and 71Lu with acetylacetone (HAa) has been studied at 25 ±0.1 deg. C by the liquid-liquid extraction technique in the system 0.02-3.5 M HAa in benzene/1.0 M Na(H)ClO4 using trace amounts of radioactive lanthanides. The stepwise formation constants, Kn=[LnAan][LnAan-1]-1[Aa-]-1 (n=2 to 4), the distribution constant of the neutral complex LnAa3 between the phases (P3), and the self-adduct formation of LnAa3 x HAa in the organic phase (Kadd1) have been evaluated. To obtain the necessary data for a precise evaluation of the lower formation constants, distribution values as low as 0.0001 had to be measured with high accuracy in the pH range 3-9. To make this possible the investigation was made by the recently developed AKUFVE-LISOL technique. A survey of the results on all the lanthanides studied in this series is also given. (author)

  10. Chiral separation of alpha-diimine Ru(II) and Fe(II) complexes and assessment of association constants of their complexes with sulfated cyclodextrins by capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Sázelová, Petra; Koval, Dušan; Severa, Lukáš; Teplý, Filip; Kašička, Václav

    Salzburg: Society of Analytical Chemistry, 2014. P509. [ISC 2014. International Symposium on Chromatography /30./. 14.09.2014-18.09.2014, Salzburg] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S; GA ČR GA13-32974S Institutional support: RVO:61388963 Keywords : alpha-diimine Fe(II) complex * capillary electrophoresis * association constant Subject RIV: CB - Analytical Chemistry, Separation

  11. Baryons and Chiral Symmetry

    CERN Document Server

    Liu, Keh-Fei

    2016-01-01

    The relevance of chiral symmetry in baryons is highlighted in three examples in the nucleon spectroscopy and structure. The first one is the importance of chiral dynamics in understanding the Roper resonance. The second one is the role of chiral symmetry in the lattice calculation of $\\pi N \\sigma$ term and strangeness. The third one is the role of chiral $U(1)$ anomaly in the anomalous Ward identity in evaluating the quark spin and the quark orbital angular momentum. Finally, the chiral effective theory for baryons is discussed.

  12. A sensitive fluorescent sensor of lanthanide ions

    CERN Document Server

    Bekiari, V; Lianos, P

    2003-01-01

    A fluorescent probe bearing a diazostilbene chromophore and a benzo-15-crown-5 ether moiety is a very efficient sensor of lanthanide ions. The ligand emits strong fluorescence only in the presence of specific ions, namely lanthanide ions, while the emission wavelength is associated with a particular ion providing high sensitivity and resolution.

  13. Chirality in Nonlinear Optics

    Science.gov (United States)

    Haupert, Levi M.; Simpson, Garth J.

    2009-05-01

    The past decade has witnessed the emergence of new measurement approaches and applications for chiral thin films and materials enabled by the observations of the high sensitivity of second-order nonlinear optical measurements to chirality. In thin films, the chiral response to second harmonic generation and sum frequency generation (SFG) from a single molecular monolayer is often comparable with the achiral response. The chiral specificity also allows for symmetry-allowed SFG in isotropic chiral media, confirming predictions made ˜50 years ago. With these experimental demonstrations in hand, an important challenge is the construction of intuitive predictive models that allow the measured chiral response to be meaningfully related back to molecular and macromolecular structure. This review defines and considers three distinct mechanisms for chiral effects in uniaxially oriented assemblies: orientational chirality, intrinsic chirality, and isotropic chirality. The role of each is discussed in experimental and computational studies of bacteriorhodopsin films, binaphthol, and collagen. Collectively, these three model systems support a remarkably simple framework for quantitatively recovering the measured chiral-specific activity.

  14. Synthesis and photophysical studies of chiral helical macrocyclic scaffolds via coordination-driven self-assembly of 1,8,9,16-tetraethynyltetraphenylene. formation of monometallic platinum(II) and dimetallic platinum(II)-ruthenium(II) complexes.

    Science.gov (United States)

    Lin, Fang; Peng, Hai-Yan; Chen, Jing-Xing; Chik, David T W; Cai, Zongwei; Wong, Keith M C; Yam, Vivian W W; Wong, Henry N C

    2010-11-24

    This paper is concerned with the synthesis and reactions of enantiopure 1,8,9,16-tetraethynyltetraphenylene (3). We obtained 3 in 34% yield through four steps starting from 1,8,9,16-tetrahydroxytetraphenylene (2a) via a functional group interconversion strategy. On the basis of this chiral "helical" building block, three rigid helical macrocycles 14, 15, and 22 were designed. Complexes 14 and 15 were constructed via coordination-driven self-assembly with platinum(II) complexes 8 and 9b, while 22 cannot be obtained successfully. Then macrocycle 28 was designed on the structural basis of 22 to which octyl chains were introduced, in the hope of improving the solubility of the complex. Macrocycle 28 was finally formed and was characterized by NMR spectroscopy, elemental analysis, and electrospray mass spectrometry. For the enantiopure 15 and 28, circular dichroism (CD) spectra also exhibited chiral properties. Complexes 27 and 28 both exhibited an intense emission band at 621 nm in acetonitrile at 298 K upon excitation at λ > 420 nm. PMID:21033663

  15. Chiral Rotational Spectroscopy

    CERN Document Server

    Cameron, Robert P; Barnett, Stephen M

    2015-01-01

    We introduce chiral rotational spectroscopy: a new technique that enables the determination of the individual optical activity polarisability components $G_{XX}'$, $G_{YY}'$, $G_{ZZ}'$, $A_{X,YZ}$, $A_{Y,ZX}$ and $A_{Z,XY}$ of chiral molecules, in a manner that reveals the enantiomeric constitution of a sample whilst yielding an incisive signal even for a racemate. Chiral rotational spectroscopy could find particular use in the analysis of molecules that are chiral by virtue of their isotopic constitution and molecules with multiple chiral centres. The principles that underpin chiral rotational spectroscopy can also be exploited in the search for molecular chirality in space, which, if found, may add weight to hypotheses that biological homochirality and indeed life itself are of cosmic origin.

  16. On chiral and non chiral 1D supermultiplets

    Energy Technology Data Exchange (ETDEWEB)

    Toppan, Francesco, E-mail: toppan@cbpf.b [Centro Brasileiro de Pesquisas Fisicas (TEO/CBPF), Rio de Janeiro, RJ (Brazil). Coordenacao de Fisica Teorica

    2011-07-01

    In this talk I discuss and clarify some issues concerning chiral and non chiral properties of the one-dimensional supermultiplets of the N-extended supersymmetry. Quaternionic chirality can be defined for N = 4, 5, 6, 7, 8. Octonionic chirality for N = 8 and beyond. Inequivalent chiralities only arise when considering several copies of N = 4 or N = 8 supermultiplets. (author)

  17. Chiral symmetry and chiral-symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Peskin, M.E.

    1982-12-01

    These lectures concern the dynamics of fermions in strong interaction with gauge fields. Systems of fermions coupled by gauge forces have a very rich structure of global symmetries, which are called chiral symmetries. These lectures will focus on the realization of chiral symmetries and the causes and consequences of thier spontaneous breaking. A brief introduction to the basic formalism and concepts of chiral symmetry breaking is given, then some explicit calculations of chiral symmetry breaking in gauge theories are given, treating first parity-invariant and then chiral models. These calculations are meant to be illustrative rather than accurate; they make use of unjustified mathematical approximations which serve to make the physics more clear. Some formal constraints on chiral symmetry breaking are discussed which illuminate and extend the results of our more explicit analysis. Finally, a brief review of the phenomenological theory of chiral symmetry breaking is presented, and some applications of this theory to problems in weak-interaction physics are discussed. (WHK)

  18. Enantioselectively controlled release of chiral drug (metoprolol) using chiral mesoporous silica materials

    Science.gov (United States)

    Guo, Zhen; Du, Yu; Liu, Xianbin; Ng, Siu-Choon; Chen, Yuan; Yang, Yanhui

    2010-04-01

    Chiral porous materials have attracted burgeoning attention on account of their potential applications in many areas, such as enantioseparation, chiral catalysis, chemical sensors and drug delivery. In this report, chiral mesoporous silica (CMS) materials with various pore sizes and structures were prepared using conventional achiral templates (other than chiral surfactant) and a chiral cobalt complex as co-template. The synthesized CMS materials were characterized by x-ray diffraction, nitrogen physisorption, scanning electron microscope and transmission electron microscope. These CMS materials, as carriers, were demonstrated to be able to control the enantioselective release of a representative chiral drug (metoprolol). The release kinetics, as modeled by the power law equation, suggested that the release profiles of metoprolol were remarkably dependent on the pore diameter and pore structure of CMS materials. More importantly, R- and S-enantiomers of metoprolol exhibited different release kinetics on CMS compared to the corresponding achiral mesoporous silica (ACMS), attributable to the existence of local chirality on the pore wall surface of CMS materials. The chirality of CMS materials on a molecular level was further substantiated by vibrational circular dichroism measurements.

  19. Enantioselectively controlled release of chiral drug (metoprolol) using chiral mesoporous silica materials

    Energy Technology Data Exchange (ETDEWEB)

    Guo Zhen; Liu Xianbin; Ng, Siu-Choon; Chen Yuan; Yang Yanhui [School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459 (Singapore); Du Yu, E-mail: du_yu@jlu.edu.cn, E-mail: yhyang@ntu.edu.sg [College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China)

    2010-04-23

    Chiral porous materials have attracted burgeoning attention on account of their potential applications in many areas, such as enantioseparation, chiral catalysis, chemical sensors and drug delivery. In this report, chiral mesoporous silica (CMS) materials with various pore sizes and structures were prepared using conventional achiral templates (other than chiral surfactant) and a chiral cobalt complex as co-template. The synthesized CMS materials were characterized by x-ray diffraction, nitrogen physisorption, scanning electron microscope and transmission electron microscope. These CMS materials, as carriers, were demonstrated to be able to control the enantioselective release of a representative chiral drug (metoprolol). The release kinetics, as modeled by the power law equation, suggested that the release profiles of metoprolol were remarkably dependent on the pore diameter and pore structure of CMS materials. More importantly, R- and S-enantiomers of metoprolol exhibited different release kinetics on CMS compared to the corresponding achiral mesoporous silica (ACMS), attributable to the existence of local chirality on the pore wall surface of CMS materials. The chirality of CMS materials on a molecular level was further substantiated by vibrational circular dichroism measurements.

  20. Enantioselectively controlled release of chiral drug (metoprolol) using chiral mesoporous silica materials

    International Nuclear Information System (INIS)

    Chiral porous materials have attracted burgeoning attention on account of their potential applications in many areas, such as enantioseparation, chiral catalysis, chemical sensors and drug delivery. In this report, chiral mesoporous silica (CMS) materials with various pore sizes and structures were prepared using conventional achiral templates (other than chiral surfactant) and a chiral cobalt complex as co-template. The synthesized CMS materials were characterized by x-ray diffraction, nitrogen physisorption, scanning electron microscope and transmission electron microscope. These CMS materials, as carriers, were demonstrated to be able to control the enantioselective release of a representative chiral drug (metoprolol). The release kinetics, as modeled by the power law equation, suggested that the release profiles of metoprolol were remarkably dependent on the pore diameter and pore structure of CMS materials. More importantly, R- and S-enantiomers of metoprolol exhibited different release kinetics on CMS compared to the corresponding achiral mesoporous silica (ACMS), attributable to the existence of local chirality on the pore wall surface of CMS materials. The chirality of CMS materials on a molecular level was further substantiated by vibrational circular dichroism measurements.

  1. Magnetic moments of lanthanide 3-, 4-nitrobenzoates and 3,4-dinitrobenzoates

    International Nuclear Information System (INIS)

    The magnetic moments for lanthanide 3-nitro and 4-nitrobenzoates were determined at 298 K and those for 3,4-dinitrobenzoates of rare earth elements over the temperature range 77 - 296 K. The complexes of 3,4-dinitrobenzoates of rare earth were found to obey the Curie-Weiss law. The values of μ calculated for all complexes (except that for europium 3,4-dinitrobenzoates) are close to those obtained for Ln3+ ions by Hund and Van Vleck. The results reveal that irrespective of the kind of ligands (3-nitro, 4-nitro or 3,4-dinitrobenzoates) no influence of their field on lanthanide ions occurs. (author)

  2. Chirality and angular momentum in optical radiation

    CERN Document Server

    Coles, Matt M

    2012-01-01

    This paper develops, in precise quantum electrodynamic terms, photonic attributes of the "optical chirality density", one of several measures long known to be conserved quantities for a vacuum electromagnetic field. The analysis lends insights into some recent interpretations of chiroptical experiments, in which this measure, and an associated chirality flux, have been treated as representing physically distinctive "superchiral" phenomena. In the fully quantized formalism the chirality density is promoted to operator status, whose exploration with reference to an arbitrary polarization basis reveals relationships to optical angular momentum and helicity operators. Analyzing multi-mode beams with complex wave-front structures, notably Laguerre-Gaussian modes, affords a deeper understanding of the interplay between optical chirality and optical angular momentum. By developing theory with due cognizance of the photonic character of light, it emerges that only the spin angular momentum of light is engaged in such...

  3. `Americium(III)/trivalent lanthanides` separation using organothiophosphinic acids

    Energy Technology Data Exchange (ETDEWEB)

    Hill, C.; Madic, C.; Baron, P. [CEA Marcoule, 30 - Bagnols-sur-Ceze (France); Ozawa, Masaki; Tanaka, Yasumasa

    1997-12-31

    The present paper describes the extraction of neodymium and other lanthanides by saponified Cyanex 301 acid. The saponification of commercial Cyanex 301 acid favoured the extraction of macro concentrations of neodymium from sodium nitrate aqueous solutions (pH{sub eq} {approx} 4). The amount of lanthanide extracted in the organic phase always reached the third of the initial concentration of saponified Cyanex 301 acid, which assumed a cation exchange mechanism to occur during the extraction. No nitrate anion took part in the complex formation. This paper also compares the abilities of purified Cyanex 301, Cyanex 302 and Cyanex 272 acids to extract and separate {sup 241}Am(III) from {sup 152}Eu(III). Very high separation factors S.F.{sub Am/Eu} were observed in the case of purified Cyanex 301 acid. Finally some studies are presented herein using tri-n-butylphosphate (TBP) as a synergistic extractant with Cyanex 301 acid to separate actinides from trivalent lanthanide. (author)

  4. Sensitisation of visible and NIR lanthanide emission by InPZnS quantum dots in bi-luminescent hybrids.

    Science.gov (United States)

    Molloy, Jennifer K; Lincheneau, Christophe; Karimdjy, Maria Moula; Agnese, Fabio; Mattera, Lucia; Gateau, Christelle; Reiss, Peter; Imbert, Daniel; Mazzanti, Marinella

    2016-03-25

    The synthesis of stable hybrid nanoparticles combining InPZnS@ZnSe/ZnS quantum dots (QDs) and grafted lanthanide complexes has been performed using two different approaches in organic and aqueous media. The final bi-luminescent hybrids exhibit Ln(III) (Ln = Eu and Yb) centred luminescence upon QD excitation, suggesting that an energy transfer occurs from the QD to the lanthanide. PMID:26941180

  5. Using lanthanide chelates and uranyl compounds for diagnostic by fluoroimmunoassays

    International Nuclear Information System (INIS)

    The importance of the luminescence of lanthanide ions and UO22+ is related to its peculiar characteristics, e.g. long lifetime and line-like emission bands in the visible, which make these ions unique among the species that are known to luminescence. Recent developments in the field of supramolecular chemistry have allowed the design of ligands capable of encapsulating lanthanide ions, thus forming kinetically inert complexes. By introduction of chromophoric groups in these ligands, an intense luminescence of the ion can be obtained via the 'antenna effect', defined as a light conversion process involving distinct absorbing (ligand) and emitting (metal ion) components. In such a process, the quantities that contribute to the luminescence intensity are the efficiency of the absorption, the efficiency of the ligand-metal energy transfer, and the efficiency of the metal luminescence. Encapsulation of lanthanide ions with suitable ligands may therefore give rise to 'molecular devices' capable to emit strong, long-lived luminescence. Besides the intrinsic interest in their excited state properties, compounds of lanthanide ions, in particular of the Eu3+ and Tb3+ ions, and now UO22+ are important for their potential use as luminescent labels for biological species in fluoroimmunoassays (FIAs). This is most interesting because fluorimetric labeling represents an alternative method to the use of radioactive labels, which has long been the most common way of quantifying immunoreactions. In this article we report information about luminescent materials, which gave a good signal to quantify biological molecules by TR-FIA, DELFIA , DSLFIA, RIA and FRET. (author)

  6. Selective extraction of trivalent actinides from lanthanides with dithiophosphinic acids and tributylphosphate

    International Nuclear Information System (INIS)

    A variety of chemical systems have been developed to separate trivalent actinides from lanthanides based on the slightly stronger complexation of the trivalent actinides with ligands that contain soft donor atoms. The greater stability of the actinide complexes in these systems has often been attributed to a slightly greater covalent bonding component for the actinide ions relative to the lanthanide ions. The authors have investigated several synergistic extraction systems that use ligands with a combination of oxygen and sulfur donor atoms that achieve a good group separation of the trivalent actinides and lanthanides. For example, the combination of dicyclohexyldithiophosphinic acid and tributylphosphate has shown separation factors of up to 800 for americium over europium in a single extraction stage. Such systems could find application in advanced partitioning schemes for nuclear waste

  7. Chiral Superfluidity for QCD

    CERN Document Server

    Kalaydzhyan, Tigran

    2014-01-01

    We argue that the strongly coupled quark-gluon plasma formed at LHC and RHIC can be considered as a chiral superfluid. The "normal" component of the fluid is the thermalized matter in common sense, while the "superfluid" part consists of long wavelength (chiral) fermionic states moving independently. We use the bosonization procedure with a finite cut-off and obtain a dynamical axion-like field out of the chiral fermionic modes. Then we use relativistic hydrodynamics for macroscopic description of the effective theory obtained after the bosonization. Finally, solving the hydrodynamic equations in gradient expansion, we find that in the presence of external electromagnetic fields or rotation the motion of the "superfluid" component gives rise to the chiral magnetic, chiral vortical, chiral electric and dipole wave effects. Latter two effects are specific for a two-component fluid, which provides us with crucial experimental tests of the model.

  8. Mechanical separation of chiral dipoles by chiral light

    CERN Document Server

    Canaguier-Durand, Antoine; Genet, Cyriaque; Ebbesen, Thomas W

    2013-01-01

    Optical forces take on a specific form when involving chiral light fields interacting with chiral objects. We show that optical chirality density and flow can have mechanical effects through reactive and dissipative components of chiral forces exerted on chiral dipoles. Remarkably, these force components are directly related to standard observables: optical rotation and circular dichroism, respectively. As a consequence, resulting forces and torques are dependent on the enantiomeric form of the chiral dipole. This leads to promising strategies for the mechanical separation of chiral objects using chiral light forces.

  9. How strongly are the magnetic anisotropy and coordination numbers correlated in lanthanide based molecular magnets?

    Indian Academy of Sciences (India)

    Tulika Gupta; Gopalan Rajaraman

    2014-09-01

    Ab initio CASSCF+RASSI-SO investigations on a series of lanthanide complexes [LnIII = Dy(1), Tb(2), Ce(3), Nd(4), Pr(5) and Sm(6)] have been undertaken and in selected cases (for 1, 2, 3 and 4) coordination number (C.N.) around the LnIII ion has been gradually varied to ascertain the effect of C.N. on the magnetic anisotropy. Our calculations reveal that complex 3 possesses the highest barrier height for reorientation of magnetisation (Ueff) and predict that 3 is likely to exhibit Single Molecule Magnet (SMM) behaviour. Complex 5 on the other hand is predicted to preclude any SMM behaviour as there is no intrinsic barrier for reorientation of magnetization. Ground state anisotropy of all the complexes show mixed behaviour ranging from pure Ising type to fully rhombic behaviour. Coordination number around the lanthanide ion is found to alter the magnetic behaviour of all the lanthanide complexes studied and this is contrary to the general belief that the lanthanide ions are inert and exert small ligand field interaction.High symmetric low-coordinate LnIII complexes are found to yield large Ueff values and thus should be the natural targets for achieving very large blocking temperatures.

  10. Synthesis and Application of Chiral Spiro Cp Ligands in Rhodium-Catalyzed Asymmetric Oxidative Coupling of Biaryl Compounds with Alkenes.

    Science.gov (United States)

    Zheng, Jun; Cui, Wen-Jun; Zheng, Chao; You, Shu-Li

    2016-04-27

    The vastly increasing application of chiral Cp ligands in asymmetric catalysis results in growing demand for novel chiral Cp ligands. Herein, we report a new class of chiral Cp ligands based on 1,1'-spirobiindane, a privileged scaffold for chiral ligands and catalysts. The corresponding Rh complexes are shown to be excellent catalysts in asymmetric oxidative coupling reactions, providing axially chiral biaryls in 19-97% yields with up to 98:2 er. PMID:27070297

  11. Chirally enhanced solubilization through perylene-based surfactant

    International Nuclear Information System (INIS)

    Recently we introduced a rationally designed surfactant which forms energy transfer complexes with carbon nanotubes. We investigate the chiral selectivity of this compound, a perylene derived surfactant, through photoluminescence (PL) measurements, and find a strong enhancement of the luminescence intensity for one particular group of chiralities. The effect is striking, with luminescence increases of several hundred percent. Chiral selectivity of the investigated surfactant compound as compared to solubilization through sodium cholate (SC). Small numbers indicate chirality, large numbers laola family. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Chirally enhanced solubilization through perylene-based surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, Friederike; Reich, Stephanie; Setaro, Antonio [Department of Physics, Freie Universitaet Berlin, Arnimallee 14, 14195 Berlin (Germany); Heek, Timm; Haag, Rainer [Department of Chemistry, Freie Universitaet Berlin, Takustrasse 3, 14195 Berlin (Germany)

    2012-12-15

    Recently we introduced a rationally designed surfactant which forms energy transfer complexes with carbon nanotubes. We investigate the chiral selectivity of this compound, a perylene derived surfactant, through photoluminescence (PL) measurements, and find a strong enhancement of the luminescence intensity for one particular group of chiralities. The effect is striking, with luminescence increases of several hundred percent. Chiral selectivity of the investigated surfactant compound as compared to solubilization through sodium cholate (SC). Small numbers indicate chirality, large numbers laola family. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Rapid separation of lanthanides and actinides on small particle based reverse phase supports

    Energy Technology Data Exchange (ETDEWEB)

    Datta, A.; Sivaraman, N.; Srinivasan, T.G.; Vasudeva Rao, P.R. [Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

    2010-07-01

    This paper presents the results on the use of short columns (3-5 cm long) with small particle size (1.8 {mu}m) for high performance liquid chromatographic separation of individual lanthanides and uranium from plutonium as well as uranium from thorium to achieve rapid separations i.e. separation time as short as 3.6 min for individual lanthanides, 1 min for thorium-uranium and 4.2 min for uranium from plutonium. These advantages can be exploited to significantly reduce analysis time, liquid waste generation as well as dose to operator when radioactive samples are analysed e.g. burn-up determination. In the present work, a dynamic ion-exchange chromatographic separation technique was employed using camphor-10-sulfonic acid (CSA) as the ion-pairing reagent and {alpha}-hydroxy isobutyric acid ({alpha}-HIBA) as the complexing reagent for the isolation of individual lanthanides as well as the separation of uranium from thorium. Uranium was separated from Pu(III) as well as Pu(IV) by reverse phase HPLC technique. The reverse phase HPLC was also investigated for the isolation and quantitative determination of uranium from thorium as well as lanthanide group from uranium. The dynamic ion-exchange technique using small particle support was demonstrated for measuring the concentrations of lanthanide fission products such as La, Ce, Pr, Nd and Sm in the dissolver solution of fast reactor fuel. Similarly, the assay of uranium in the dissolver solution of fast reactor was carried out using reverse phase HPLC technique. The rapid separation technique using reverse phase HPLC was also demonstrated for separation of lanthanides as a group from uranium matrix; samples of LiCl-KCl eutectic salt containing chlorides of lanthanides in uranium matrix (typically 1: 2000) were analysed. (orig.)

  14. Electric field effects on nuclear magnetic shielding of the 1:1 and 2:1 (homo and heterochiral) complexes of XOOX' (X, X' = H, CH3) with lithium cation and their chiral discrimination

    Science.gov (United States)

    Alkorta, Ibon; Elguero, José; Provasi, Patricio F.; Pagola, Gabriel I.; Ferraro, Marta B.

    2011-09-01

    The set of 1:1 and 2:1 complexes of XOOX' (X, X' = H, CH3) with lithium cation has been studied to determine if they are suitable candidates for chiral discrimination in an isotropic medium via nuclear magnetic resonance spectroscopy. Conventional nuclear magnetic resonance is unable to distinguish between enantiomers in the absence of a chiral solvent. The criterion for experimental detection is valuated by the isotropic part of nuclear shielding polarisability tensors, related to a pseudoscalar of opposite sign for two enantiomers. The study includes calculations at coupled Hartree-Fock and density functional theory schemes for 17O nucleus in each compound. Additional calculations for 1H are also included for some compounds. A huge static homogeneous electric field, perpendicular to the magnetic field of the spectromer, as big as ≈1.7 × 108 V m-1 should be applied to observe a shift of ≈1 ppm for 17O magnetic shielding in the proposed set of complexes.

  15. On chirality of slime mould.

    Science.gov (United States)

    Dimonte, Alice; Adamatzky, Andrew; Erokhin, Victor; Levin, Michael

    2016-02-01

    Left-right patterning and lateralised behaviour is an ubiquitous aspect of plants and animals. The mechanisms linking cellular chirality to the large-scale asymmetry of multicellular structures are incompletely understood, and it has been suggested that the chirality of living cells is hardwired in their cytoskeleton. We examined the question of biased asymmetry in a unique organism: the slime mould Physarum polycephalum, which is unicellular yet possesses macroscopic, complex structure and behaviour. In laboratory experiment using a T-shape, we found that Physarum turns right in more than 74% of trials. The results are in agreement with previously published studies on asymmetric movement of muscle cells, neutrophils, liver cells and growing neural filaments, and for the first time reveal the presence of consistently-biased laterality in the fungi kingdom. Exact mechanisms of the slime mould's direction preference remain unknown. PMID:26747637

  16. Doped Chiral Polymer Metamaterials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Doped Chiral Polymer Metamaterials (DCPM) with tunable resonance frequencies have been developed by adding plasmonic inclusions into chiral polymers with variable...

  17. Higher order atomic effects in the lanthanides

    International Nuclear Information System (INIS)

    Laser induced fluorescence spectroscopy, Doppler-free two-photon spectroscopy, inter modulated optogalvanic spectroscopy, Doppler-free saturation absorption spectroscopy and improvements of these methods in respect of the different properties of the lanthanides are presented in detail

  18. The proton complex of a diaza-macropentacycle: structure, slow formation, and chirality induction by ion pairing with the optically active 1,1'-binaphthyl-2,2'-diyl phosphate anion.

    Science.gov (United States)

    Bonnot, Clément; Chambron, Jean-Claude; Espinosa, Enrique; Bernauer, Klaus; Scholten, Ulrich; Graff, Roland

    2008-10-17

    The protonation of a sterically crowded [N2S6] macropentacycle (1) with 1 equiv of CF3SO3H in CDCl3 is slow and gives the singly (oo(+) [1 x H](+)) and doubly (o(+)o(+) [1 x 2H](2+)) protonated forms as kinetic products, the i(+)o form of [1 x H](+) being the thermodynamic product. i(+)o [1 x H](+) is C3 helically chiral in the solid state and in solution. The barrier to racemization (DeltaG(double dagger)) of the [1 x H](+) propeller is >71 kJ mol(-1). The ammonium proton is encapsulated in the tetrahedral coordination sphere provided by the endo (i) nitrogen bridgehead atom and the three proximal thioether sulfurs, which makes [1 x H](+) a proton complex. Use of the optically active acid (R)-(-)- or (S)-(+)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate (BNPH) in chloroform allowed us to induce a significant diastereomeric excess (24% de), which produced a detectable ICD. The de was decreased in acetone-d6 (10%), suggesting that the sense of chirality of [1 x H](+) is controlled by ion-pair interactions. Detailed NMR studies allowed us to locate the chiral anion on the endo side of [1 x H](+), in the cavity lined by endo t-Bu groups, and to establish that the rate of anion exchange in [1 x H][(S,R)-(+/-)-BNP] was higher than the rate of propeller inversion of [1 x H](+). PMID:18811199

  19. Chiral geometry in multiple chiral doublet bands

    Science.gov (United States)

    Zhang, Hao; Chen, Qibo

    2016-02-01

    The chiral geometry of multiple chiral doublet bands with identical configuration is discussed for different triaxial deformation parameters γ in the particle rotor model with . The energy spectra, electromagnetic transition probabilities B(M1) and B(E2), angular momenta, and K-distributions are studied. It is demonstrated that the chirality still remains not only in the yrast and yrare bands, but also in the two higher excited bands when γ deviates from 30°. The chiral geometry relies significantly on γ, and the chiral geometry of the two higher excited partner bands is not as good as that of the yrast and yrare doublet bands. Supported by Plan Project of Beijing College Students’ Scientific Research and Entrepreneurial Action, Major State 973 Program of China (2013CB834400), National Natural Science Foundation of China (11175002, 11335002, 11375015, 11461141002), National Fund for Fostering Talents of Basic Science (NFFTBS) (J1103206), Research Fund for Doctoral Program of Higher Education (20110001110087) and China Postdoctoral Science Foundation (2015M580007)

  20. Lanthanides in the frame of Molecular Magnetism

    OpenAIRE

    Gatteschi D

    2014-01-01

    Molecular magnetism is producing new types of materials which cover up to date aspects of basic science together with possible applications. This article highlights recent results from the point of view of lanthanides which are now intensively used to produce single molecule magnets, single chain and single ion magnets. After a short introduction reminding the main steps of development of molecular magnetism, the basic properties of lanthanides will be covered highlighting important features ...