Journal articles: 'Ions lanthanides'

1

Pałasz, A., and P. Czekaj. "Toxicological and cytophysiological aspects of lanthanides action." Acta Biochimica Polonica 47, no. 4 (December 31, 2000): 1107–14. http://dx.doi.org/10.18388/abp.2000_3963.

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Lanthanides, also called rare-earth elements, are an interesting group of 15 chemically active, mainly trivalent, f-electronic, silvery-white metals. In fact, lanthanides are not as rare as the name implies, except for promethium, a radioactive artificial element not found in nature. The mean concentrations of lanthanides in the earth's crust are comparable to those of life-important elements like iodine, cobalt and selenium. Many lanthanide compounds show particular magnetic, catalytic and optic properties, and that is why their technical applications are so extensive. Numerous industrial sources enable lanthanides to penetrate into the human body and therefore detailed toxicological studies of these metals are necessary. In the liver, gadolinium selectively inhibits secretion by Kupffer cells and it decreases cytochrome P450 activity in hepatocytes, thereby protecting liver cells against toxic products of xenobiotic biotransformation. Praseodymium ion (Pr3+) produces the same protective effect in liver tissue cultures. Cytophysiological effects of lanthanides appear to result from the similarity of their cationic radii to the size of Ca2+ ions. Trivalent lanthanide ions, especially La3+ and Gd3+, block different calcium channels in human and animal cells. Lanthanides can affect numerous enzymes: Dy3+ and La3+ block Ca2+-ATPase and Mg2+-ATPase, while Eu3+ and Tb3+ inhibit calcineurin. In neurons, lanthanide ions regulate the transport and release of synaptic transmitters and block some membrane receptors, e.g. GABA and glutamate receptors. It is likely that lanthanides significantly and uniquely affect biochemical pathways, thus altering physiological processes in the tissues of humans and animals.

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Maza-Rodriguez, J., P. Olivera-Pastor, S. Bruque, and A. Jimenez-Lopez. "Exchange selectivity of lanthanide ions in montmorillonite." Clay Minerals 27, no. 1 (March 1992): 81–89. http://dx.doi.org/10.1180/claymin.1992.027.1.08.

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AbstractThe exchange of Ca2+ and Na+ by tanthanide ions (Ln3+ = Pr3+, Gd3+, Er3+) in montmorillonite was investigated at two different ionic strengths (0·01 and 0·1 mol/kg). Preferential sorption of Ln3+ was observed and variable selectivity coefficients were found depending upon the lanthanide concentration in the solid, and ionic strength. The highest exchange extent of Ln3+ always occurred for the system Na+/Ln3+, but the exchange selectivities of Ln3+ were generally higher in the exchange system Ca2+/Ln3+. Although the relative affinity of montmorillonite for the three lanthanide ions was similar, distinctive behaviour between Pr3+ and the heavier lanthanides, Gd3+ and Er3+, was noted. The study of Ln3+ adsorption in trace amounts showed specific adsorption of lanthanides at high concentrations of Na+ in the external solution and that the exchange stoichiometries in the interlayer regions were 3 : 1 at equilibrium pH = 4.

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Alakhras, Fadi. "Kinetic Studies on the Removal of Some Lanthanide Ions from Aqueous Solutions Using Amidoxime-Hydroxamic Acid Polymer." Journal of Analytical Methods in Chemistry 2018 (July 8, 2018): 1–7. http://dx.doi.org/10.1155/2018/4058503.

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Lanthanide metal ions make distinctive and essential contributions to recent global proficiency. Extraction and reuse of these ions is of immense significance especially when the supply is restricted. In light of sorption technology, poly(amidoxime-hydroxamic) acid sorbents are synthesized and utilized for the removal of various lanthanide ions (La3+, Nd3+, Sm3+, Gd3+, and Tb3+) from aqueous solutions. The sorption speed of trivalent lanthanides (Ln3+) depending on the contact period is studied by a batch equilibrium method. The results reveal fast rates of metal ion uptake with highest percentage being achieved after 15–30 min. The interaction of poly(amidoxime-hydroxamic) acid sorbent with Ln3+ ions follows the pseudo-second-order kinetic model with a correlation coefficient R2 extremely high and close to unity. Intraparticle diffusion data provide three linear plots indicating that the sorption process is affected by two or more steps, and the intraparticle diffusion rate constants are raised among reduction of ionic radius of the studied lanthanides.

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Citron, Irvin M., Patrick M. Hanlon, and Stephen Arthur. "Ultraviolet Spectroscopic Determination of Five Lanthanide Elements without Prior Separation." Applied Spectroscopy 47, no. 6 (June 1993): 764–72. http://dx.doi.org/10.1366/0003702934067027.

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This investigation has resulted in an analytical method for the quantitative determination of total lanthanide concentration in aqueous solution by absorbance at 240 nm in the ultraviolet followed by quantitative determination of individual lanthanide ion concentrations by the use of concentration-responsive absorption peaks in the 190–235 nm region. The 240-nm peak is present and is proportional to concentration regardless of the ligand employed to complex the lanthanides (including H2O). The individual lanthanide/ligand peaks in the 190–235 nm region were selected on the basis of their separation from one another, their linearity of absorbance vs. concentration, and their statistical reliability based on replicate sample analyses. Lanthanides involved in this investigation were La+3, Nd+3, Eu+3, Ho+3, and Yb+3. Ligands ultimately selected for complexation were citrate for La+3, Nd+3, and Ho+3, and DTPA for Eu+3, Ho+3, and Yb+3. When large amounts of heavy metal ions were present, a modified method was developed with citrate as the only complexing ligand for all five lanthanides. The method here developed permits the analyses of lanthanide ions in aqueous solution without prior separation and involves the use of comparatively inexpensive instrumentation (UV absorption spectrophotometer).

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Werts, Martinus H. V. "Making sense of Lanthanide Luminescence." Science Progress 88, no. 2 (May 2005): 101–31. http://dx.doi.org/10.3184/003685005783238435.

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The luminescence of trivalent lanthanide ions has found applications in lighting, lasers, optical telecommunications, medical diagnostics, and various other fields. This introductory review presents the basics of organic and inorganic luminescent materials containing lanthanide ions, their applications, and some recent developments. After a brief history of the discovery, purification and early spectroscopic studies of the lanthanides, the radiative and nonradiative transitions of the 4f electrons in lanthanide ions are discussed. Lanthanide-doped phosphors, glasses and crystals as well as luminescent lanthanide complexes with organic ligands receive attention with respect to their preparation and their applications. Finally, two recent developments in the field of luminescent materials are addressed: near-infrared luminescent lanthanide complexes and lanthanide-doped nanoparticles.

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Zhang, Hailong, Ao Li, Kai Li, Zhipeng Wang, Xiaocheng Xu, Yaxing Wang, Matthew V. Sheridan, et al. "Ultrafiltration separation of Am(VI)-polyoxometalate from lanthanides." Nature 616, no. 7957 (April 19, 2023): 482–87. http://dx.doi.org/10.1038/s41586-023-05840-z.

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AbstractPartitioning of americium from lanthanides (Ln) present in used nuclear fuel plays a key role in the sustainable development of nuclear energy1–3. This task is extremely challenging because thermodynamically stable Am(III) and Ln(III) ions have nearly identical ionic radii and coordination chemistry. Oxidization of Am(III) to Am(VI) produces AmO22+ ions distinct with Ln(III) ions, which has the potential to facilitate separations in principle. However, the rapid reduction of Am(VI) back to Am(III) by radiolysis products and organic reagents required for the traditional separation protocols including solvent and solid extractions hampers practical redox-based separations. Herein, we report a nanoscale polyoxometalate (POM) cluster with a vacancy site compatible with the selective coordination of hexavalent actinides (238U, 237Np, 242Pu and 243Am) over trivalent lanthanides in nitric acid media. To our knowledge, this cluster is the most stable Am(VI) species in aqueous media observed so far. Ultrafiltration-based separation of nanoscale Am(VI)-POM clusters from hydrated lanthanide ions by commercially available, fine-pored membranes enables the development of a once-through americium/lanthanide separation strategy that is highly efficient and rapid, does not involve any organic components and requires minimal energy input.

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Martín-Rodríguez, R., R. Valiente, F. Aguado, and A. C. Perdigón. "Highly efficient photoluminescence from isolated Eu3+ ions embedded in high-charge mica." J. Mater. Chem. C 5, no. 39 (2017): 10360–68. http://dx.doi.org/10.1039/c7tc01818e.

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Incorporation of lanthanide ions in synthetic clay minerals is a promising approach to combine the efficient sharp-line emission of lanthanides with the unique structural stability and high adsorption capacity of high-charge micas.

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Onghena, Bieke, Eleonora Papagni, Ernesto Rezende Souza, Dipanjan Banerjee, Koen Binnemans, and Tom Vander Hoogerstraete. "Speciation of lanthanide ions in the organic phase after extraction from nitrate media by basic extractants." RSC Advances 8, no. 56 (2018): 32044–54. http://dx.doi.org/10.1039/c8ra06712k.

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Dhepe, A. S., and A. B. Zade. "Spectrophotometric Study of Ternary Complex Forming Systems of Some Lanthanide Metal Ions with Eriochrome Cyanine R in Presence of Cetylpyridinium Bromide for Microdetermination." E-Journal of Chemistry 8, no. 3 (2011): 1264–74. http://dx.doi.org/10.1155/2011/871685.

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Study of coordination compounds of lanthanide elements has received a great attention due to growing applications in science and technology. Number of chromogenic reagents form water soluble colored complexes with lanthanides. Eriochrome cyanine R (ECR) a member of triphenylmethane type of dye has been reported to form green colored complexes with lanthanides and has been used for microdetermination of these metal ions. Addition of cationic surfactant, Cetylpyridinium bromide (CPB), a cationic surfactant sensitizes the color reactions of Gd(III), Tb(III), Dy(III), Ho(III) and Lu(III) with ECR. Formation of water soluble, highly colored ternary complexes with a considerable bathochromic shift of about 50 nm in presence of surfactant has been observed. Optimum reaction conditions and other analytical parameters were also evaluated. Stoichiometric ratio 1:3:3 of Ln: ECR: CPB are responsible for the observed rise in molar absorptivity and sensitivity. Beer’s law was obeyed between 0.50 to 13.00 ppm. Effective photometric range and molar absorptivity of these ternary complexes have been calculated. Effect of some common interfering ions on determination of these lanthanide metal ions was studied. A simple, rapid and highly sensitive spectrophotometeric method has been proposed for the determination of metal ions understudy.

10

Semenishyn, Nikolay, Serhii Smola, Mariia Rusakova, and Natalia Rusakova. "4f-LUMINESCENCE OF LANTHANIDE IONS IN REGIOISOMERIC CORROLE COMPLEXES." Ukrainian Chemistry Journal 87, no. 9 (October 25, 2021): 35–44. http://dx.doi.org/10.33609/2708-129x.87.09.2021.35-44.

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Isomeric ditopic corroles and complexes of Yb (III), Nd (III) and Er (III) based on them were synthesized and corrole-photosensitized 4f-luminescence in near infrared region was revealed. The structure of isomeric complexes allows adjusting the distance between the corrole core and lanthanide ion. The obtained results show that the sensitization mechanism changes drastically for both different lanthanides and isomeric forms.

11

Gagné, Olivier Charles. "Bond-length distributions for ions bonded to oxygen: results for the lanthanides and actinides and discussion of the f-block contraction." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 74, no. 1 (January 12, 2018): 49–62. http://dx.doi.org/10.1107/s2052520617017425.

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Bond-length distributions have been examined for 84 configurations of the lanthanide ions and 22 configurations of the actinide ions bonded to oxygen, for 1317 coordination polyhedra and 10 700 bond distances for the lanthanide ions, and 671 coordination polyhedra and 4754 bond distances for the actinide ions. A linear correlation between mean bond length and coordination number is observed for the trivalent lanthanides ions bonded to O2−. The lanthanide contraction for the trivalent lanthanide ions bonded to O2− is shown to vary as a function of coordination number, and to diminish in scale with an increasing coordination number. The decrease in mean bond length from La3+ to Lu3+ is 0.25 Å for coordination number (CN) 6 (9.8%), 0.22 Å for CN 7 (8.7%), 0.21 Å for CN 8 (8.0%), 0.21 Å for CN 9 (8.2%) and 0.18 Å for CN 10 (6.9%). The crystal chemistry of Np5+ and Np6+ is shown to be very similar to that of U6+ when bonded to O2−, but differs for Np7+.

12

Tigaa, Rodney A., Raul E. Ortega, Xinsong Lin, and Geoffrey F. Strouse. "A Versatile Tripodal Ligand for Sensitizing Lanthanide (LnIII) Ions and Color Tuning." Chemistry 3, no. 1 (January 26, 2021): 138–45. http://dx.doi.org/10.3390/chemistry3010011.

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Lanthanide (LnIII) ions were successfully chelated and sensitized with a tripodal ligand. The absolute LnIII-centered emission efficiencies were ~3% for both the europium(III) (EuIII) and terbium (TbIII) complexes and up to 54% for the cerium(III) (CeIII) complex. The differences in emission quantum yields for the early lanthanides (CeIII) and the mid lanthanides (EuIII and TbIII) were attributed to their d–f and f–f nature, respectively. Despite the low quantum yield of the EuIII complex, the combination of the residual ligand fluorescence and the red EuIII emission resulted in a bluish-white material with the Commission Internationale de l’Eclairage (CIE) coordinates (0.258, 0.242). Thus, metal complexes of the ligand could be used in the generation of single-component white-light-emitting materials.

13

Li, Yuyang, and Ronald Kluger. "Increased efficiency in biomimetic Lewis acid–base pair catalyzed monoacylation of diols by acyl phosphate monoesters." FACETS 2, no. 2 (September 1, 2017): 682–89. http://dx.doi.org/10.1139/facets-2017-0047.

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Acyl phosphate monoesters are biomimetic acylation reagents that require coordination to metal ions to react with cis-diol substrates in water. With lanthanide catalysts, outcomes are compromised by (1) the competitive lanthanide-promoted hydrolysis of the acyl phosphate reagents as well as by (2) the high affinity of lanthanum ions for the phosphate monoester by-product. Based on analysis of the mechanism of the process, optimizing reaction conditions can selectively inhibit the lanthanum-promoted hydrolysis of acyl phosphate monoesters. Furthermore, using zinc salts and lead salts in place of lanthanides enhances the reactivity of the reactants and causes less complexation of the metal ion with the by-products.

14

Weißhoff, Hardy, Katharina Janek, Peter Henklein, Herbert Schumann, and Clemens Mügge. "Elution Behavior and Structural Characterization of N- and C-functionalized DOTA Complexes for the Labelling of Biomolecules." Zeitschrift für Naturforschung B 64, no. 10 (October 1, 2009): 1159–68. http://dx.doi.org/10.1515/znb-2009-1008.

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Two types of lanthanide complexes of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) for the labelling of biomolecules were investigated by HPLC, MS and NMR spectroscopy. The elution behavior of lanthanide complexes of N-functionalized DOTA [1,4,7,10-tetraazacyclododecane- 1,4,7-triacetic acid-10-maleimidoethylacetamide (nDOTA-Mal) and 1-{2-[4-(maleimido- N-propylacetamidobutyl)amino]-2-oxoethyl}-1,4,7,10-tetraazacyclododecane-4,7,10-triacetic acid (nDOTA-Bu-Mal)] and C-functionalized DOTA [2-{4-(maleimido-N-propylacetamido)benzyl}-1,4, 7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (cDOTA-Bnz-Mal) and 2-(4-isothiocyanatobenzyl)- 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (cDOTA-Bnz-NCS)] was compared. N-functionalized lanthanide DOTA complexes coelute as required for their use as ICAT-analogous reagents. The complexation of the C-functionalized DOTA with lanthanides results in two fractions separable by HPLC. Coelution is observed for the main fractions of the lanthanide complexes. The retention times of the minor fractions show a dependence on the ionic radii of the metal ions. MALDI spectra of lanthanide-DOTA-peptide conjugates including different monoisotopic lanthanides demonstrate the advantage of the mass variations for extensive peptide and protein investigations.

15

Lin, Ying-Ting, Rong-Xuan Liu, Gilbert Audira, Michael Edbert Suryanto, Marri Jmelou M. Roldan, Jiann-Shing Lee, Tzong-Rong Ger, and Chung-Der Hsiao. "Lanthanides Toxicity in Zebrafish Embryos Are Correlated to Their Atomic Number." Toxics 10, no. 6 (June 19, 2022): 336. http://dx.doi.org/10.3390/toxics10060336.

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Rare earth elements (REEs) are critical metallic materials with a broad application in industry and biomedicine. The exponential increase in REEs utilization might elevate the toxicity to aquatic animals if they are released into the water due to uncareful handling. The specific objective of our study is to explore comprehensively the critical factor of a model Lanthanide complex electronic structures for the acute toxicity of REEs based on utilizing zebrafish as a model animal. Based on the 96 h LC50 test, we found that the majority of light REEs display lower LC50 values (4.19–25.17 ppm) than heavy REEs (10.30–41.83 ppm); indicating that they are atomic number dependent. Later, linear regression analyses further show that the average carbon charge on the aromatic ring (aromatic Cavg charge) can be the most significant electronic structural factor responsible for the Lanthanides’ toxicity in zebrafish embryos. Our results confirm a very strong correlation of LC50 to Lanthanide’s atomic numbers (r = 0.72), Milliken charge (r = 0.70), and aromatic Cavg charge (r = −0.85). This most significant correlation suggests a possible toxicity mechanism that the Lanthanide cation’s capability to stably bind to the aromatic ring on the residue of targeted proteins via a covalent chelating bond. Instead, the increasing ionic bond character can reduce REEs’ toxicity. In addition, Lanthanide toxicity was also evaluated by observing the disruption of photo motor response (PMR) activity in zebrafish embryos. Our study provides the first in vivo evidence to demonstrate the correlation between an atomic number of Lanthanide ions and the Lanthanide toxicity to zebrafish embryos.

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Lazicki, Andy Peter, and Johna Leddy. "Investigating Lanthanide Ions for Catalysis of Alcohols." ECS Meeting Abstracts MA2023-01, no. 50 (August 28, 2023): 2585. http://dx.doi.org/10.1149/ma2023-01502585mtgabs.

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Small molecule alcohols (methanol, ethanol, 2-propanol) are fuels limited by their oxidative kinetics. For these small molecules to be used as fuels, catalysts must be developed. One domain of chemicals which has not had its catalytic properties entirely studied are lanthanides. These lanthanides contain many properties not found in d-block metals or other compounds frequently used as catalysts. The ability to catalyze oxidation of small molecule alcohols is studied here. Performance of these lanthanides as a catalyst are measured for each small molecule using common voltametric techniques. Plausible mechanisms for any charge transfer enhancement are also estimated.

17

Angyal, SJ, L. Littlemore, and PAJ Gorin. "Lanthanide-Induced Shifts in the 13C N.M.R. Spectra of epi-Inositol and Some Anhydrohexoses. The Anomalous Behaviour of the Heavy Lanthanides." Australian Journal of Chemistry 38, no. 3 (1985): 411. http://dx.doi.org/10.1071/ch9850411.

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The shifts induced in the 13C n.m.r . spectrum of epi-inositol by the addition of various lanthanide ions have been determined and have been analysed in terms of contact and pseudocontact interactions. The behaviour of the three heavy lanthanides was found to be anomalous, probably owing to their smaller ionic radii and their lesser extent of hydration. Similar measurements have also been carried out on four 1,6- anhydro-β-D-hexopyranoses.

18

Pentón-Madrigal, A., Y. Mendez-González, A. Peláiz-Barranco, F. Calderón-Piñar, L. A. S. de Oliveira, J. Belhadi, and Y. Gagou. "Study ofAandBsites order in lanthanide-doped lead titanate ferroelectric system." Powder Diffraction 31, no. 1 (February 17, 2016): 23–30. http://dx.doi.org/10.1017/s0885715615000998.

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Pb0.88Ln0.08TiO3ferroelectric system, whereLn= La, Sm, Eu, and Dy, has been characterized using Scanning Electron Microscopy, Raman spectroscopy, and X-ray diffraction experiments. Softening of the lowest transverse optical phonon modeE(1TO) was evaluated as a function of the rare earths’ ionic radius suggesting partial occupation of lanthanide ions at theAandBsites of the perovskite structure. Using Rietveld refinements, it has been established a higher incorporation of Ln3+ions into theAsites of the perovskite structure than that of theBsites for the studied ceramics. The occupation atBsites increases slightly with the decreases of the ionic radii of the lanthanides.

19

Gao, Qi, Shuai Han, Qing Ye, Shuiyuan Cheng, Tianfang Kang, and Hongxing Dai. "Effects of Lanthanide Doping on the Catalytic Activity and Hydrothermal Stability of Cu-SAPO-18 for the Catalytic Removal of NOx (NH3-SCR) from Diesel Engines." Catalysts 10, no. 3 (March 17, 2020): 336. http://dx.doi.org/10.3390/catal10030336.

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Lanthanide (La, Ce, Nd, Gd, Tb, Ho or Lu)-doped Cu-SAPO-18 samples were prepared using the ion-exchange method. Physicochemical properties of the samples were systematically characterized by a number of analytical techniques, and the effects of lanthanide doping on catalytic activity and hydrothermal stability of the Cu-SAPO-18 catalysts for the NH3-SCR reaction were examined. It is shown that the doping of lanthanide elements could affect the interaction between the active components (copper ions) and the AEI-structured SAPO-18 support. The inclusion of some lanthanides significantly slowed down hydrolysis of the catalyst during hydrothermal aging treatment process, leading to an enhanced catalytic activity at both low and high temperatures and hydrothermal stability. In particular, Ce doping promoted the Cu2+ ions to migrate to the energetically favorable sites for enhancement in catalytic activity, whereas the other lanthanide ions exerted little or an opposite effect on the migration of Cu2+ ions. Additionally, Ce doping could improve hydrothermal stability of the Cu-SAPO-18 catalyst by weakening hydrolysis of the catalyst during the hydrothermal aging treatment process. Ce doping increased the catalytic activity of Cu-SAPO-18 at low and high temperatures, which was attributed to modifications of the redox and/or isolated Cu2+ active centers.

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Wójcik, Grzegorz. "Sorption Behaviors of Light Lanthanides(III) (La(III), Ce(III), Pr(III), Nd(III)) and Cr(III) Using Nitrolite." Materials 13, no. 10 (May 14, 2020): 2256. http://dx.doi.org/10.3390/ma13102256.

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The sorption of light lanthanides(III) (La(III), Ce(III), Pr(III), Nd(III)) and chromium(III) ions from acidic solutions on Nitrolite was studied at varying ions concentrations, pH, contact time and temperatures. The sorption capacity of lanthanides(III) and chromium(III) ions were examined in the ranges 2–9 and 2–5, respectively. The adsorption capacities of all metals are increase with the increasing pH (up to initial pH 9), despite the potential precipitation of metals at higher pH values. Therefore, an initial pH 9 of lanthanides gives the highest adsorption capacities. The kinetics of sorption chromium(III) and light lanthanides(III) were investigated. The experimental data were analyzed using the pseudo-first-order, pseudo-second-order forms, Elovich, and intra-particle diffusion models. The sorption kinetics of investigated ions was described by pseudo-second-order model the best. The results indicate the endothermic process of Cr(III), La(III), Ce(III), Pr(III) and Nd(III) ions sorption. The sorption capacities of La(III) 4.77 mg/g, Ce(III) 4.45 mg/g, Pr(III) 4.30 mg/g, Nd(III) 4.13 mg/g and Cr(III) 2.39 mg/g were calculated from the Langmiur model, which describes adsorption better than Freundlich and Dubinin–Radushkevich.

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Yang, Han Yu. "Lanthanide-Based Nanoprobes for Time-Resolved Luminescence Imaging on Various Ions and Molecules." Materials Science Forum 1075 (November 30, 2022): 9–17. http://dx.doi.org/10.4028/p-76fds1.

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Lanthanide-doped upconversion nanoparticles (Ln-UCNPs) have been extensively explored in the biological field. In particular, Ln-UCNPs with near-infrared (NIR) fluorescence have tremendous potential for biological imaging because of their outstanding photo-and chemo-stability, extended photoluminescence lifetimes, low long-term toxicities and narrow photoluminescence bandwidths as well as minimal background interferences. Using predesigned energy transfer routes makes it possible to get upconversion luminescence from lanthanides' 4f-4f optical transitions. This article clarifies the key working principles and superiorities of Ln-UCNPs for bioimaging. A crucial overview of recent advances in biological detection adopting lanthanide-based luminescence resonance energy transfer (LRET) mechanisms is presented while emphasizing the importance of modifying Ln-UCNPs to obtain a more efficient energy transfer mechanism.

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Savić, Aleksandar, Anna M. Kaczmarek, Rik Van Deun, and Kristof Van Hecke. "DNA Intercalating Near-Infrared Luminescent Lanthanide Complexes Containing Dipyrido[3,2-a:2′,3′-c]phenazine (dppz) Ligands: Synthesis, Crystal Structures, Stability, Luminescence Properties and CT-DNA Interaction." Molecules 25, no. 22 (November 13, 2020): 5309. http://dx.doi.org/10.3390/molecules25225309.

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In order to create near-infrared (NIR) luminescent lanthanide complexes suitable for DNA-interaction, novel lanthanide dppz complexes with general formula [Ln(NO3)3(dppz)2] (Ln = Nd3+, Er3+ and Yb3+; dppz = dipyrido[3,2-a:2′,3′-c]phenazine) were synthesized, characterized and their luminescence properties were investigated. In addition, analogous compounds with other lanthanide ions (Ln = Ce3+, Pr3+, Sm3+, Eu3+, Tb3+, Dy3+, Ho3+, Tm3+, Lu3+) were prepared. All complexes were characterized by IR spectroscopy and elemental analysis. Single-crystal X-ray diffraction analysis of the complexes (Ln = La3+, Ce3+, Pr3+, Nd3+, Eu3+, Er3+, Yb3+, Lu3+) showed that the lanthanide’s first coordination sphere can be described as a bicapped dodecahedron, made up of two bidentate dppz ligands and three bidentate-coordinating nitrate anions. Efficient energy transfer was observed from the dppz ligand to the lanthanide ion (Nd3+, Er3+ and Yb3+), while relatively high luminescence lifetimes were detected for these complexes. In their excitation spectra, the maximum of the strong broad band is located at around 385 nm and this wavelength was further used for excitation of the chosen complexes. In their emission spectra, the following characteristic NIR emission peaks were observed: for a) Nd3+: 4F3/2 → 4I9/2 (870.8 nm), 4F3/2 → 4I11/2 (1052.7 nm) and 4F3/2 → 4I13/2 (1334.5 nm); b) Er3+: 4I13/2 → 4I15/2 (1529.0 nm) c) Yb3+: 2F5/2 → 2F7/2 (977.6 nm). While its low triplet energy level is ideally suited for efficient sensitization of Nd3+ and Er3+, the dppz ligand is considered not favorable as a sensitizer for most of the visible emitting lanthanide ions, due to its low-lying triplet level, which is too low for the accepting levels of most visible emitting lanthanides. Furthermore, the DNA intercalation ability of the [Nd(NO3)3(dppz)2] complex with calf thymus DNA (CT-DNA) was confirmed using fluorescence spectroscopy.

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Krsmanović, R., Stefano Polizzi, and P. Canton. "Characterization of Nanoporous Lanthanide-Doped Gadolinium Gallium Garnet Powders Obtained by Propellant Synthesis." Materials Science Forum 494 (September 2005): 143–48. http://dx.doi.org/10.4028/www.scientific.net/msf.494.143.

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In the present work we study the nanocrystalline powders of lanthanide-doped Gd3Ga5O12 (GGG, gadolinium gallium garnet) prepared using propellant synthesis. A series of GGG samples containing a number of different trivalent lanthanide ions (Tm, Er, Ho, Eu, Sm, Nd, and Pr) in different quantities (1%, 5%, 10%) were produced. Samples were characterized by X-ray diffraction (pre- and post calcination) for phase identification and line-broadening analysis, and by electron microscopy (SEM and TEM) for morphological and nanostructural investigation. Thermal behavior of the powder was investigated by thermal gravimetric analysis (TGA) and differential thermal analysis (DTA). The samples have a polycrystalline porous structure. Elemental microanalysis made by energy dispersive X-ray spectroscopy (EDX) detector attached to TEM and XRD unit-cell determinations confirmed that the lanthanides ions entered the structure of GGG. Crystallites have a high degree of disorder.

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Romanova, Kseniya A., and Yuriy G. Galyametdinov. "Simulation of Energy Transfer Processes in Mesogenic Binuclear Complexes of Lanthanides(III)." Liquid Crystals and their Application 24, no. 1 (March 28, 2024): 22–35. http://dx.doi.org/10.18083/lcappl.2024.1.22.

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Quantum-chemical simulation of the molecular structure and excited state energies of some mesogenic binuclear complexes of lanthanides(III) with substituted β-diketones and Lewis bases have been performed. Correlations between geometric parameters, structural features of the complexes' coordination polyhedra, potential liquid-crystalline properties, and luminescence efficiency were analyzed. According to the calculated values of the lowest singlet and triplet excited states of the ligands, energy level diagrams were constructed and the main channels of intramolecular energy transfer between the excited levels of the ligands and lanthanide(III) ions were defined. The process of interionic energy transfer was elucidated and the ligand environment for the creation of mesogenic binuclear lanthanide(III) complexes with intense luminescence was proposed.

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Liu, Xiaohui, Tuerxun Aidilibike, Junjie Guo, Yangyang Li, Weihua Di, and Weiping Qin. "Upconversion luminescence of Sm2+ ions." RSC Advances 7, no. 23 (2017): 14010–14. http://dx.doi.org/10.1039/c7ra00071e.

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Nahar, Sultana N. "Theoretical Spectra of Lanthanides for Kilonovae Events: Ho I-III, Er I-IV, Tm I-V, Yb I-VI, Lu I-VII." Atoms 12, no. 4 (April 17, 2024): 24. http://dx.doi.org/10.3390/atoms12040024.

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The broad emission bump in the electromagnetic spectra observed following the detection of gravitational waves created during the kilonova event of the merging of two neutron stars in August 2017, named GW170817, has been linked to the heavy elements of lanthanides (Z = 57–71) and a new understanding of the creation of heavy elements in the r-process. The initial spectral emission bump has a wavelength range of 3000–7000 Å, thus covering the region of ultraviolet (UV) to optical (O) wavelengths, and is similar to those seen for lanthanides. Most lanthanides have a large number of closely lying energy levels, which introduce extensive sets of radiative transitions that often form broad regions of lines of significant strength. The current study explores these broad features through the photoabsorption spectroscopy of 25 lanthanide ions, Ho I-III, Er I-IV, Tm I-V, Yb I-VI, and Lu I-VII. With excitation only to a few orbitals beyond the ground configurations, we find that most of these ions cover a large number of bound levels with open 4f orbitals and produce tens to hundreds of thousands of lines that may form one or multiple broad features in the X-ray to UV, O, and infrared (IR) regions. The spectra of 25 ions are presented, indicating the presence, shapes, and wavelength regions of these features. The accuracy of the atomic data used to interpret the merger spectra is an ongoing problem. The present study aims at providing improved atomic data for the energies and transition parameters obtained using relativistic Breit–Pauli approximation implemented in the atomic structure code SUPERSTRUCTURE and predicting possible features. The present data have been benchmarked with available experimental data for the energies, transition parameters, and Ho II spectrum. The study finds that a number of ions under the present study are possible contributors to the emission bump of GW170817. All atomic data will be made available online in the NORAD-Atomic-Data database.

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Lazaris, Dimitrios, Ioannis Sismanidis, Vasileios Drosos, Evripidis Farmakis, and and Evangelos Paleologos. "Absorption of Europium chloride from zebrafish (Danio rerio) embryos under experimental conditions." E3S Web of Conferences 436 (2023): 03003. http://dx.doi.org/10.1051/e3sconf/202343603003.

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Lanthanides (Ln) have an essential role in the pollution of the environment because of their ecotoxicity. The pollution of Ln significantly increased due to their use in industry and agriculture in the last decade. Europium (Eu) is the most reactive lanthanide by far. This metal is contained in many industries wastes and it may enter the food chain. The biochemical behavior of lanthanides has been extensively studied, but there are limited studies on Eu. It is remarkable that Ln react with biologically chemical compounds, affecting competitively and replacing the basic ions of the cell such as calcium (Ca2+) and magnesium (Mg2+). Based on the international literature, there are not much data on the toxic effects of Eu mainly on aquatic organisms. Exposure of zebrafish embryos to Europium indicated that the absorption of the metal from the embryos was taken place from the earliest stages of their development.

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Dunaev, Anatoliy M., Vladimir B. Motalov, and Lev S. Kudin. "ELECTRON WORK FUNCTION OF LANTHANIDE TRIIODIDES." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 63, no. 11 (October 27, 2020): 13–20. http://dx.doi.org/10.6060/ivkkt.20206311.6292.

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Desorption enthalpies of LnI4– and Ln2I7– associative ions (Ln = La, Ce, Pr, Nd, Gd, Tb, Dy, Ho, Er, Tm, and Lu) and the enthalpy of sublimation of LnI3 molecules were determined by Knudsen effusion mass spectrometric technique. These data were used to calculate the effective values of electron work function φe of polycrystalline samples of lanthanide triiodides LnI3 for the first time. The calculation methodology is based on the study of thermochemical cycles, which include atoms, molecules, ions, and electrons being in thermodynamic equilibrium with the LnI3 crystal inside the effusion cell. The values obtained for different lanthanides turned out to be close. They lie in the range of about 2.4 – 4.4 eV with an average value in the series: φe = 3.2 ± 0.3 eV. The latter value is close to those for previously studied lanthanide tribromides. No secondary periodicity of φe was found within the calculated errors along the lanthanide series. The results obtained are in quantitative agreement with the theoretical calculation of the values of the band gap of lanthanide triiodides. Comparison of φe with other classes of lanthanide compounds such as oxides, hexaborides, and lanthanide metals shows relatively high electron emission ability yielding only to alkali and alkali-earth metals.

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Ali, Hassan, Reza Ganjali, and Farnoush Faridbod. "A lutetium pvc membrane sensor based on (2-oxo-1,2-diphenylethylidene)-n-phenylhydrazinecarbothioamide." Journal of the Serbian Chemical Society 76, no. 9 (2011): 1295–305. http://dx.doi.org/10.2298/jsc100826114a.

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Based on the former experience on the design and construction of metal ions sensors, especially those of high sensitivity for lanthanides, (2-oxo-1,2-diphenylethylidene)-N-phenylhydrazinecarbothioamide (PHCT) was used to construct a Lu3+ PVC sensor exhibiting a Nernstian slope of 19.8?0.3 mV decade-1. The sensor was found to function well over a concentration range of 1.0?10-2 and 1.0?10-6 mol L-1 of the target ion with a detection limit of 6.8?10-7 mol L-1. The sensor selectivity against many common alkaline, alkaline earth, transition, heavy metals and specially lanthanide ions was very good and it functioned well in the pH range 2.5 - 8.7. Having a lifetime of at least 2 months and a short response time of ?5 s, the sensor was successfully used as an indicator electrode in the potentiometric titration of Lu3+ ions.

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Simon, A., Hj Mattausch, N. B. Mikheev, and C. Keller. "Zum Einbau von einigen Lanthaniden in Gd2Cl3 / Incorporation of Some Lanthanides into Gd2Cl3." Zeitschrift für Naturforschung B 42, no. 6 (June 1, 1987): 666–68. http://dx.doi.org/10.1515/znb-1987-0602.

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Abstract Co-crystallization experiments with radioactive isotopes of lanthanides (Ce, Nd, Eu, Gd, Tb, Dy, Tm, Yb) show that only Tb is incorporated by Gd2Cl3 in a significant amount. The results are discussed in terms of the electronic configuration of Ln2+ ions as well as redox potentials E°(Ln3+/Ln2+).

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Berthod, Alain, Jun Xiang, Serge Alex, and Colette Gonnet-Collet. "Chromatographie à contre courant et micelles inverses pour la séparation et l'extraction de cations métalliques." Canadian Journal of Chemistry 74, no. 2 (February 1, 1996): 277–86. http://dx.doi.org/10.1139/v96-031.

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Countercurrent chromatography (CCC) is a separation technique in which the stationary phase is a liquid. Diethylhexyl phosphoric acid (DEHPA) forms reverse micelles in heptane. Metallic ions, located in an aqueous phase, can be extracted into the aqueous core of the reverse micelles in the heptane phase. A CCC apparatus can be considered as a powerful mixing and extracting machine with efficiency above several hundreds of theoretical plates. La3+, Ce3+, Pr3+, and Nd3+ lanthanide cations were separated using CCC with a DEHPA-containing heptane stationary phase. Studying the retention variations with aqueous mobile phase pH, it was possible to determine the lanthanide extraction constants and separation coefficients. Overloading conditions are described. Frontal chromatography was performed using a Co2+ and Ni2+ solution. The Co2+ ions were concentrated in the heptane + DEHPA stationary phase, a part of the solution was deionized, and another part was enriched in only Ni2+ ions. This method also produced the extraction constants and separation coefficients. The use of CCC with a complexing stationary phase can be applied to any cation for ion filtering and concentration, or for deionization of aqueous phases. Key words: countercurrent chromatography, CCC; ion extraction, ion filtering, deionization, lanthanides, transition metals.

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Martinez-Martin, Paloma, Josefina Perles, and Juan Carlos Rodriguez-Ubis. "Crystal Structure Dependence of the Energy Transfer from Tb(III) to Yb(III) in Metal–Organic Frameworks Based in Bispyrazolylpyridines." Crystals 10, no. 2 (January 27, 2020): 69. http://dx.doi.org/10.3390/cryst10020069.

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Luminescent mixed lanthanide metal−organic framwork (MOF) materials have been prepared from two polyheterocyclic diacid ligands, 2,6-bis(3-carboxy-1-pyrazolyl)pyridine and 2,6-bis(4-carboxy-1-pyrazolyl)pyridine. The crystal structures of the two organic molecules are presented together with the structures for the MOFs obtained by hydrothermal synthesis either with Yb(III) or mixed Tb(III)/Yb(III) ions. Different coordination architectures result from each ligand, revealing also important differences between the lanthanides. The mixed lanthanide metal−organic frameworks also present diverse luminescent behavior; in the case of 2,6-bis(4-carboxy-1-pyrazolyl)pyridine, where no coordinated water is present in the metal environment, Tb(III) and Yb(III) characteristic emission is observed by excitation of the bispyrazolylpyridine chromophore.

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Lansman, J. B. "Blockade of current through single calcium channels by trivalent lanthanide cations. Effect of ionic radius on the rates of ion entry and exit." Journal of General Physiology 95, no. 4 (April 1, 1990): 679–96. http://dx.doi.org/10.1085/jgp.95.4.679.

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Currents flowing through single dihydropyridine-sensitive Ca2+ channels were recorded from cell-attached patches on C2 myotubes. In the presence of dihydropyridine agonist to prolong the duration of single-channel openings, adding micromolar concentrations of lanthanum (La), cerium (Ce), neodymium (Nd), gadolinium (Gd), dysprosium (Dy), or ytterbium (Yb) to patch electrodes containing 110 mM BaCl2 caused the unitary Ba2+ currents to fluctuate between fully open and shut states. The kinetics of channel blockade followed the predictions of a simple open channel block model in which the fluctuations of the single-channel current arose from the entry and exit of blocking ions from the pore. Entry rates for all the lanthanides tested were relatively insensitive to membrane potential, however, exit rates depended strongly on membrane potential increasing approximately e-fold per 23 mV with hyperpolarization. Individual lanthanide ions differed in both the absolute rates of ion entry and exit: entry rates decreased as cationic radius decreased; exit rates also decreased with cationic radius during the first part of the lanthanide series but then showed little change during the latter part of the series. Overall, the results support the idea that smaller ions enter the channel more slowly, presumably because they dehydrate more slowly; smaller ions also bind more tightly to a site within the channel pore, but lanthanide residence time within the channel approaches a maximum for the smaller cations with radii less than or equal to that of Ca2+.

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Chan, Eric J., Jack M. Harrowfield, Brian W. Skelton, and Allan H. White. "X-Ray Structural Studies of Small-Bite Ligands on Large Cations – Lanthanide(III) Ions and Dimethylphosphate." Australian Journal of Chemistry 73, no. 6 (2020): 539. http://dx.doi.org/10.1071/ch19506.

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Reactions of lanthanide chlorides or trifluoracetates (tfa) or picrates with trimethylphosphate alone in the first two cases or trimethylphosphate plus 1,10-phenanthroline or 2,2′;6′,2′′-terpyridine in the third, result in the formation of crystalline products containing dimethylphosphate (dmp–). Single crystal X-ray structural characterisation of these materials has shown that the stoichiometrically simple Ln(dmp)3 species obtained with chloride reactants and the lighter lanthanides are polymeric and commonly dimorphic, while the stoichiometrically more variable mixed dmp/tfa complexes have structures closely related to one phase of the Ln(dmp)3 family, and the presence of picrate and aza-aromatic ligands enables the isolation of Y and Lu derivatives containing binuclear species. In all, the dmp– ligands adopt exclusively the κ1O;κ1O′ bridging mode, the overall results indicating that this should apply to the complete lanthanide series.

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Jona, I., and A. Martonosi. "The effects of membrane potential and lanthanides on the conformation of the Ca2+-transport ATPase in sarcoplasmic reticulum." Biochemical Journal 234, no. 2 (March 1, 1986): 363–71. http://dx.doi.org/10.1042/bj2340363.

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The effects of Ca2+, lanthanide ions (Gd3+, La3+ and Pr3+) and membrane potential on the fluorescence of tryptophan and covalently bound fluorescein were analysed in native and fluorescein isothiocyanate (FITC)-labelled sarcoplasmic reticulum vesicles. The binding of Ca2+ and lanthanides to the Ca2+-ATPase increases the fluorescence intensity of tryptophan and decreases the fluorescence intensity of FITC; the dependence of these effects on cation concentration is consistent with the involvement of the high-affinity Ca2+-binding sites of the Ca2+-ATPase in the cation-induced fluorescence changes. The fluorescence of FITC-labelled sarcoplasmic reticulum vesicles is also influenced by membrane potential changes induced by ion substitution. Inside positive potential increases, while inside negative potential decreases, the fluorescence of bound FITC. Smaller potential-dependent changes in tryptophan fluorescence were also observed. The effects of Ca2+, lanthanides and membrane potential on the fluorescence of tryptophan and FITC are discussed in terms of the two major conformations of the Ca2+-ATPase (E1 and E2), that are assumed to alternate during Ca2+ transport. The observations support the suggestion [Dux, Taylor, Ting-Beall & Martonosi (1985) J. Biol. Chem. 260, 11730-11743] that the vanadate-induced crystals of Ca2+-ATPase represent the E2, while the Ca2+ and lanthanide-induced crystals the E1, conformation of the enzyme.

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Flakina, Alexandra M., Elena I. Zhilyaeva, Gennady V. Shilov, Maxim A. Faraonov, Svetlana A. Torunova, and Dmitri V. Konarev. "Layered Organic Conductors Based on BEDT-TTF and Ho, Dy, Tb Chlorides." Magnetochemistry 8, no. 11 (October 28, 2022): 142. http://dx.doi.org/10.3390/magnetochemistry8110142.

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Molecular semiconductors with lanthanide ions have been synthesized based on BEDT-TTF and lanthanide chlorides: (BEDT-TTF)2[HoCl2(H2O)6]Cl2(H2O)2 (1, which contains a 4f holmium cation), and (BEDT-TTF)2LnCl4(H2O)n (Ln = Dy, Tb, Ho (2–4), which contain 4f anions of lanthanides). Conductivity and EPR measurements have been carried out along with the SQUID magnetometry, and the crystal structure has been established for 1. The structure of 1 is characterized by an alternation of organic radical cation layers composed of BEDT-TTF chains and inorganic layers consisting of chains of the [HoCl2(H2O)6]+ cations interlinked by chlorine anions and crystallization water molecules. The magnetic susceptibility of 1–3 determined mainly by lanthanide ions follows the Curie–Weiss law with the Weiss temperatures of −3, −3, −2 K for 1–3, respectively, indicating weak antiferromagnetic coupling between paramagnetic lanthanide ions. The signals attributed to the BEDT-TTF+· radical cations only are observed in the EPR spectra of 1–3, which makes it possible to study their magnetic behavior. There are two types of chains in the organic layers of 1: the chains composed of neutral molecules and those formed by BEDT-TTF+· radical cations. As a result, uniform 1D antiferromagnetic coupling of spins is observed in the BEDT-TTF+· chains with estimated exchange interaction J = −10 K. The study of dynamic magnetic properties of 1–3 shows that these compounds are not SMMs.

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Edington, Sean C., Andrea Gonzalez, Thomas R. Middendorf, D. Brent Halling, Richard W. Aldrich, and Carlos R. Baiz. "Coordination to lanthanide ions distorts binding site conformation in calmodulin." Proceedings of the National Academy of Sciences 115, no. 14 (March 15, 2018): E3126—E3134. http://dx.doi.org/10.1073/pnas.1722042115.

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The Ca2+-sensing protein calmodulin (CaM) is a popular model of biological ion binding since it is both experimentally tractable and essential to survival in all eukaryotic cells. CaM modulates hundreds of target proteins and is sensitive to complex patterns of Ca2+ exposure, indicating that it functions as a sophisticated dynamic transducer rather than a simple on/off switch. Many details of this transduction function are not well understood. Fourier transform infrared (FTIR) spectroscopy, ultrafast 2D infrared (2D IR) spectroscopy, and electronic structure calculations were used to probe interactions between bound metal ions (Ca2+ and several trivalent lanthanide ions) and the carboxylate groups in CaM’s EF-hand ion-coordinating sites. Since Tb3+ is commonly used as a luminescent Ca2+ analog in studies of protein−ion binding, it is important to characterize distinctions between the coordination of Ca2+ and the lanthanides in CaM. Although functional assays indicate that Tb3+ fully activates many Ca2+-dependent proteins, our FTIR spectra indicate that Tb3+, La3+, and Lu3+ disrupt the bidentate coordination geometry characteristic of the CaM binding sites’ strongly conserved position 12 glutamate residue. The 2D IR spectra indicate that, relative to the Ca2+-bound form, lanthanide-bound CaM exhibits greater conformational flexibility and larger structural fluctuations within its binding sites. Time-dependent 2D IR lineshapes indicate that binding sites in Ca2+−CaM occupy well-defined configurations, whereas binding sites in lanthanide-bound-CaM are more disordered. Overall, the results show that binding to lanthanide ions significantly alters the conformation and dynamics of CaM’s binding sites.

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Niciu, H., Dorel Radu, C. Onose, V. Maduta, Daniela Niciu, H. Stroescu, and C. S. Onose. "The Influence of the Vitreous Matrix for the Determination of the Lanthanides Doping Concentration from the Optical Transmission Spectra." Advanced Materials Research 39-40 (April 2008): 269–72. http://dx.doi.org/10.4028/www.scientific.net/amr.39-40.269.

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In contrast with transitional metals whose spectra and color depends a lot of the ligands strength field, the sensitivity of the rare earth spectra is significantly weaker. This is the reason why the color of these ions is the same whatever the basic vitreous matrix. These properties permit to establish a relation for the determination of the concentration of these ions in vitreous matrix directly from the optical transmission spectra. The paper presents some samples of silica and phosphate glasses with lanthanides content for nonlinear optical applications synthesized at a laboratory scale. VIS-NIR transmission curves are presented, for several compositions. For the correlation of the lanthanides content with the specific optical absorption peak one used a method starting from the Lambert – Beer law. For the Nd2O3 concentration determination, it was used a method proposed by D.M. Dood and D.B. Fraser for the OH groups content, with an error of +4%. For specific peaks, expressions for lanthanides concentration in ppm, related to the optical transmission were found. A possibility appears to directly find the lanthanides concentration from the absorption coefficient at specific wavelengths for each vitreous matrix. The influence of matrix is discussed.

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Ferenc, Wiesława, Beata Cristóvão, and Jan Sarzyński. "Magnetic, thermal and spectroscopic properties of lanthanide(III) 2-(4-chlorophenoxy) acetates, Ln(C8H6ClO3)3•nH2O." Journal of the Serbian Chemical Society 78, no. 9 (2013): 1335–49. http://dx.doi.org/10.2298/jsc121203043f.

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4-Chlorophenoxyacetates of lanthanides(III) were synthesized as polycrystalline hydrated solids with the general formulae: Ln(C8H6ClO3)3?2H2O (Ln = La(III), Pr(III), Sm(III), Eu(III) and Tb(III)), Ln(C8H6ClO3)3?H2O (Ln = Dy(III)) and Ln(C8H6ClO3)3?3H2O (Ln = Er(III), Tm(III), Yb(III) and Lu(III) and characterized by elemental analysis, FTIR spectroscopy, magnetic and thermogravimetric studies and also by X-ray diffraction (XRD) measurements. The complexes have colours typical for lanthanide(III) ions. The carboxylate groups bind as bidentate chelating. On heating to 1273 K in air the complexes decompose in three steps. At first they dehydrate in one stage to form anhydrous salts that next decompose to the oxides of respective metals with the intermediate formation of their oxychlorides. The gaseous products of compound thermal decomposition in nitrogen were also determined and the magnetic susceptibilities were measured over the ranges 76-303K and 1.8-303K, and their magnetic moments were calculated. The results show that 4-chlorophenoxyacetates of lanthanides(III) are high-spin complexes with weak ligand field.

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Balestrieri, Matteo, Silviu Colis, Mathieu Gallart, Guy Schmerber, Paul Bazylewski, Gap Soo Chang, Marc Ziegler, Pierre Gilliot, Abdelilah Slaoui, and Aziz Dinia. "Photon management properties of rare-earth (Nd,Yb,Sm)-doped CeO2films prepared by pulsed laser deposition." Physical Chemistry Chemical Physics 18, no. 4 (2016): 2527–34. http://dx.doi.org/10.1039/c5cp04961j.

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Halubek-Gluchowska, Katarzyna, Damian Szymański, Thi Ngoc Lam Tran, Maurizio Ferrari, and Anna Lukowiak. "Upconversion Luminescence of Silica–Calcia Nanoparticles Co-doped with Tm3+ and Yb3+ Ions." Materials 14, no. 4 (February 16, 2021): 937. http://dx.doi.org/10.3390/ma14040937.

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Looking for upconverting biocompatible nanoparticles, we have prepared by the sol–gel method, silica–calcia glass nanopowders doped with different concentration of Tm3+ and Yb3+ ions (Tm3+ from 0.15 mol% up to 0.5 mol% and Yb3+ from 1 mol% up to 4 mol%) and characterized their structure, morphology, and optical properties. X-ray diffraction patterns indicated an amorphous phase of the silica-based glass with partial crystallization of samples with a higher content of lanthanides ions. Transmission electron microscopy images showed that the average size of particles decreased with increasing lanthanides content. The upconversion (UC) emission spectra and fluorescence lifetimes were registered under near infrared excitation (980 nm) at room temperature to study the energy transfer between Yb3+ and Tm3+ at various active ions concentrations. Characteristic emission bands of Tm3+ ions in the range of 350 nm to 850 nm were observed. To understand the mechanism of Yb3+–Tm3+ UC energy transfer in the SiO2–CaO powders, the kinetics of luminescence decays were studied.

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Misztalewska, I., A. Z. Wilczewska, O. Wojtasik, K. H. Markiewicz, P. Kuchlewski, and A. M. Majcher. "New acetylacetone-polymer modified nanoparticles as magnetically separable complexing agents." RSC Advances 5, no. 121 (2015): 100281–89. http://dx.doi.org/10.1039/c5ra20137c.

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Silva, Ricardo F., Jorge M. Sampaio, Pedro Amaro, Andreas Flörs, Gabriel Martínez-Pinedo, and José P. Marques. "Structure Calculations in Nd III and U III Relevant for Kilonovae Modelling." Atoms 10, no. 1 (February 7, 2022): 18. http://dx.doi.org/10.3390/atoms10010018.

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The detection of gravitational waves and electromagnetic signals from the neutron star merger GW170817 has provided evidence that these astrophysical events are sites where the r-process nucleosynthesis operates. The electromagnetic signal, commonly known as kilonova, is powered by the radioactive decay of freshly synthesized nuclei. However, its luminosity, colour and spectra depend on the atomic opacities of the produced elements. In particular, opacities of lanthanides and actinides elements, due to their large density of bound–bound transitions, are fundamental. The current work focuses on atomic structure calculations for lanthanide and actinide ions, which are important in kilonovae modelling of ejecta spectra. Calculations for Nd III and U III, two representative rare-earth ions, were achieved. Our aim is to provide valuable insights for future opacity calculations for all heavy elements. We noticed that the opacity of U III is about an order of magnitude greater than the opacity of Nd III due to a higher density of levels in the case of the actinide.

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Turanov, A. N., V. K. Karandashev, O. I. Artyushin, E. V. Smirnova, and V. K. Brel. "Synthesis and extraction properties of 4,5-diphosphorylated triazoles." Журнал общей химии 93, no. 4 (April 15, 2023): 577–85. http://dx.doi.org/10.31857/s0044460x23040091.

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A method for the synthesis of 4,5-diphosphorylated 1,2,3-triazoles has been developed, and the extraction of U(VI), Th(IV), and lanthanides(III) from nitric acid solutions by them was studied. A synergistic effect was found in the extraction of metal ions with mixtures of 4,5-diphosphorylated 1,2,3-triazoles and dinonylnaphthalenesulfonic acid. The stoichiometry of the extracted complexes was determined, and the influence of the structure of the extractant and the concentration of HNO3 in the aqueous phase on the efficiency of the extraction of metal ions into the organic phase was considered. It was established that 4,5-diphosphorylated 1,2,3-triazole with the octyl substituent at nitrogen atom has the highest extraction ability with respect to actinides and lanthanides in nitric acid media.

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Kurganskii, Ivan V., Evgeniya S. Bazhina, Alexander A. Korlyukov, Konstantin A. Babeshkin, Nikolay N. Efimov, Mikhail A. Kiskin, Sergey L. Veber, Alexey A. Sidorov, Igor L. Eremenko, and Matvey V. Fedin. "Mapping Magnetic Properties and Relaxation in Vanadium(IV) Complexes with Lanthanides by Electron Paramagnetic Resonance." Molecules 24, no. 24 (December 14, 2019): 4582. http://dx.doi.org/10.3390/molecules24244582.

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Vanadium(IV) complexes are actively studied as potential candidates for molecular spin qubits operating at room temperatures. They have longer electron spin decoherence times than many other transition ions, being the key property for applications in quantum information processing. In most cases reported to date, the molecular complexes were optimized through the design for this purpose. In this work, we investigate the relaxation properties of vanadium(IV) ions incorporated in complexes with lanthanides using electron paramagnetic resonance (EPR). In all cases, the VO6 moieties with no nuclear spins in the first coordination sphere are addressed. We develop and implement the approaches for facile diagnostics of relaxation characteristics in individual VO6 moieties of such compounds. Remarkably, the estimated relaxation times are found to be close to those of other vanadium-based qubits obtained previously. In the future, a synergistic combination of qubit-friendly properties of vanadium ions with single-molecule magnetism and luminescence of lanthanides can be pursued to realize new functionalities of such materials.

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Kornilov, A. D., M. S. Grigoriev, and E. V. Savinkina. "Comparison of the rare earth complexes iodides and polyiodides with biuret." Fine Chemical Technologies 17, no. 2 (June 1, 2022): 172–81. http://dx.doi.org/10.32362/2410-6593-2022-17-2-172-181.

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Objectives. Currently, several hundred polyiodide compounds have been synthesized and structurally characterized, but so far, no formation patterns for certain polyiodide ions have been revealed. The purpose of this work is to continue the search for formation regularities of polyiodides, including polyiodides of lanthanide complexes.Methods. Iodide and polyiodide of samarium complexes with biuret (BU), [Sm(BU)4]I3·BU·2H2O and [Sm(BU)4][I5][I]2, were first synthesized and characterized by X-ray diffraction analysis and infrared spectroscopy, respectively.Results. The obtained compounds complement the row of isostructural lanthanide (La–Gd) complexes. Structures of corresponding iodides and polyiodides were compared in detail. Both types of the compounds contain complex cations of the same composition; however, their structures differ significantly. The central atom coordination polyhedron can be described as a distorted square antiprism and a distorted dodecahedron, respectively. Even greater differences are observed in the outer sphere of complex compounds. The iodide compound crystals contain uncoordinated iodide ions, a biuret molecule and two water molecules. In the polyiodide compound, cations together with isolated I– ions form a three-dimensional framework with the channels, in which linear I5– ions are united in infinite linear chains by weak interactions.Conclusions. The replacement of an iodide ion with a polyiodide ion in complex compounds of lanthanides with BU leads to changes in both the inner sphere and the outer sphere of the cation complex, including the supramolecular level. The presence of iodine atom infinite linear chains in polyiodides allows expecting the presence of anisotropic electrical conductivity along this direction.

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de Melo, Fernando, Sabrina Almeida, and Henrique Toma. "Magnetic Nanohydrometallurgy Applied to Lanthanide Separation." Minerals 10, no. 6 (June 11, 2020): 530. http://dx.doi.org/10.3390/min10060530.

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Lanthanides play an important role in modern technology because of their outstanding optical, electronic, and magnetic properties. Their current hydrometallurgical processing involves lixiviation, leading to concentrates of elements whose separation requires exhaustive procedures because of their similar chemical properties. In this sense, a new nanotechnological approach is here discussed, involving the use of iron oxide nanoparticles functionalized with complexing agents, such as diethylenetriaminepentaacetic acid (DTPA), for carrying out the magnetic extraction and separation of the lanthanide ions in aqueous solution. This strategy, also known as magnetic nanohydrometallurgy (MNHM), was first introduced in 2011 for dealing with transition metal recovery in the laboratory, and has been recently extended to the lanthanide series. This technology is based on lanthanide complexation and depends on the chemical equilibrium involved. It has been better described in terms of Langmuir isotherms, considering a uniform distribution of the metal ions over the nanoparticles surface, as evidenced by high angle annular dark field microscopy. The observed affinity parameters correlate with the lanthanide ion contraction series, and the process dynamics have been studied by monitoring the nanoparticles migration under an applied magnetic field (magnetophoresis). The elements can be reversibly captured and released from the magnetically confined nanoparticles, allowing their separation by a simple acid-base treatment. It can operate in a circular scheme, facilitated by the easy magnetic recovery of the extracting agents, without using organic solvents and ionic exchange columns. MNHM has been successfully tested for the separation of the lanthanide elements from monazite mineral, and seems a promising green nanotechnology, particularly suitable for urban mining.

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Lincheneau, Christophe, Floriana Stomeo, Steve Comby, and Thorfinnur Gunnlaugsson. "Recent Highlights in the use of Lanthanide-directed Synthesis of Novel Supramolecular (Luminescent) Self-assembly Structures such as Coordination Bundles, Helicates and Sensors." Australian Journal of Chemistry 64, no. 10 (2011): 1315. http://dx.doi.org/10.1071/ch11184.

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In this short review, we focus on the recent developments within the field of coordination chemistry where mono- or multimetallic supramolecular self-assemblies are formed by employing structurally defined organic ligands, taking advantage of the high coordination requirements of the lanthanides. Such synthesis results in the formation of both structurally complex and beautiful self-assemblies. Moreover, as the lanthanide ions possess both unique magnetic (e.g. GdIII and DyIII) and luminescent properties, either in the visible (EuIII, SmIII and TbIII) or near-infrared regions (YbIII, NdIII, ErIII), these physical features are usually transferred to the self-assemblies themselves, allowing the formation of highly functional structures, such as coordination networks, as well as molecular bundles and helicates. Hence, examples of the use of lanthanide-directed synthesis of luminescent sensors, some of which are formed on solid surfaces such as gold (flat surface or nanoparticles), and imaging agents are presented. Moreover, we demonstrate that by using chiral organic ligands, lanthanide-directed synthesis can also give rise to the formation of enantiomerically pure self-assemblies, the structure of which can be probed using circularly polarized luminescence.

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Chan, Eric J., Simon A. Cotton, Jack M. Harrowfield, Brian W. Skelton, Alexandre N. Sobolev, and Allan H. White. "Polypyridines, Picrates, Lanthanides: A Plethora of Stacks?" Australian Journal of Chemistry 73, no. 6 (2020): 529. http://dx.doi.org/10.1071/ch19367.

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Reactions of the lanthanide(iii) picrates (picrate=2,4,6-trinitrophenoxide=pic) with 1,10-phenanthroline (phen) and 2,2′:6′,2′′-terpyridine (terpy) in a 1:2 molar ratio have provided crystals suitable for X-ray structure determinations in instances predominantly involving the lighter lanthanides. In all, the aza-aromatic ligands chelate the lanthanide ion, none being found as ‘free’ ligands within the lattice. The complexes of 1,10-phenanthroline have been characterised in two forms, one unsolvated (Ln=La, Sm, Eu; monoclinic, C2/c, Z 8), one an acetonitrile monosolvate (Ln=Gd; monoclinic, P21/a, Z 4), the latter being the only previously known form (with Ln=La). In both forms, the LnIII is nine-coordinate, in an approximately tricapped trigonal-prismatic environment, with two picrate ligands chelating through phenoxide and 2-nitro group oxygen atoms, the third being bound through phenoxide-O only. The 2,2′:6′,2′′-terpyridine complexes, all acetonitrile monosolvates defined for Ln=La, Gd, Er, and Y (monoclinic, C2/c, Z 4), are ionic, one picrate having been displaced from the primary coordination sphere. For Ln=La, the two bound picrates are again chelating, making the LaIII 10-coordinate in a distorted bicapped square-antiprismatic environment but in the other species they are bound through phenoxide-O only, making the LnIII ions eight-coordinate in a distorted square-antiprismatic environment. Stacked arrays of the ligands can be found in both series of complexes, with intramolecular picrate–picrate and picrate–aza-aromatic stacks being prominent features.

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Dwadasi, Balarama Sridhar, Sriram Goverapet Srinivasan, and Beena Rai. "Interfacial structure in the liquid–liquid extraction of rare earth elements by phosphoric acid ligands: a molecular dynamics study." Physical Chemistry Chemical Physics 22, no. 7 (2020): 4177–92. http://dx.doi.org/10.1039/c9cp05719f.

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MD simulations reveal the chemical and physical heterogeneity at the liquid–liquid interface, nature of complexes formed by phosphoric acid ligands with lanthanides, and the sequence of events in the extraction of these ions.

Journal articles on the topic 'Ions lanthanides'

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