Search

A new series of [Fe3−xLnx]O4 nanoparticles, with Ln = Gd; Dy; Lu and x = 0.05; 0.1; 0.15, was synthesized using the coprecipitation method. Analyses by X-ray diffraction (XRD), Rietveld refinement, and high-resolution transmission electron microscopy (HRTEM) indicate that all phases crystallized in space group Fd3¯m, characteristic of spinels. The XRD patterns, HRTEM, scanning electron microscopy analysis (SEM-EDS), and Raman spectra showed single phases. Transmission electron microscopy (TEM), Rietveld analysis, and Scherrer’s calculations confirm that these materials are nanoparticles with sizes in the range of ~6 nm to ~13 nm. Magnetic measurements reveal that the saturation magnetization (Ms) of the as-prepared ferrites increases with lanthanide chemical substitution (x), while the coercivity (Hc) has low values. The Raman analysis confirms that the compounds are ferrites and the Ms behavior can be explained by the relationship between the areas of the signals. The magnetic measurements indicate superparamagnetic behavior. The blocking temperatures (TB) were estimated from ZFC-FC measurements, and the use of the Néel equation enabled the magnetic anisotropy to be estimated.

Sandwich complexes of lanthanides have recently attracted a considerable amount of interest due to their applications as Single Molecule Magnet (SMM). Herein, a comprehensive series of heteroleptic lanthanide sandwich complexes ligated by the cyclononatetraenyl (Cnt) and the cyclooctatetraenyl (Cot) ligand [Ln(Cot)(Cnt)] (Ln=Tb, Dy, Er, Ho, Yb, and Lu) is reported. The coordination behavior of the Cnt ligand has been investigated along the series and shows different coordination patterns in the solid-state depending on the size of the corresponding lanthanide ion without altering its overall anisotropy. Besides the characterization in the solid state by single-crystal X-ray diffraction and in solution by 1 H NMR, static magnetic studies and ab initio computational studies were performed.

Abstract Polyurethanes, versatile polymers extensively explored across industries, can be augmented by incorporating complementary materials like lanthanides. This research presents a novel approach, employing a one-shot synthesis to create polyurethane-lanthanide composites using polyol, isocyanate, samarium, and holmium oxides. FTIR and Raman spectroscopy affirmed successful polyurethane matrix formation, while XRD unveiled distinct phases in lanthanide-loaded matrices versus soft, low-crystallinity polyurethane in control foam. Optical microscopy displayed morphology alterations due to samarium and holmium. Thermogravimetric analysis revealed heightened composite thermal stability compared to control foam. Looking ahead, these outcomes prompt further exploration of polyurethane-lanthanide composites, particularly in harnessing property changes for diverse applications.

ABSTRACT Lanthanides (Ln) are the most recently described life metals and are central to methylotrophy (type of metabolism in which organic substrates without carbon-carbon bonds serve as carbon and energy source) in diverse taxa. We recently characterized a novel, Ln-dependent, and Ln-accumulating methylotroph, Beijerinckiaceae bacterium RH AL1, which requires lighter Ln (La, Ce, Nd) for methanol oxidation. Starting from two sets of incubations, one with different La concentrations (50 nM and 1 µM) and one with different Ln elements [La, Nd, or an Ln cocktail (containing Ce, Nd, Dy, Ho, Er, Yb)], we could show that La concentration and different Ln elements strongly affect gene expression and intracellular Ln accumulation. Differential gene expression analysis revealed that up to 41% of the encoded genes were differentially expressed. The effects of La concentration and Ln elements were not limited to Ln-dependent methanol oxidation but reached into many aspects of metabolism. We observed that Ln influence the flagellar and chemotactic machinery and that they affect polyhydroxyalkanoate biosynthesis. The most differentially expressed genes included lanM, coding for the well-characterized lanthanide-binding protein lanmodulin, and a glucose dehydrogenase gene linked to the conversion of β-D-glucose to D-glucono-1,5-lactone, a known potential metal chelator. Electron microscopy, together with RNAseq, suggested that Beijerinckiaceae bacterium RH AL1 can discriminate between Ln elements and that they are differently taken up and accumulated. The discrimination of Ln and links between Ln and various aspects of metabolism underline a broader physiological role for Ln in Beijerinckiaceae bacterium RH AL1. IMPORTANCE Since its discovery, Ln-dependent metabolism in bacteria attracted a lot of attention due to its bio-metallurgical application potential regarding Ln recycling and circular economy. The physiological role of Ln is mostly studied dependent on presence and absence. Comparisons of how different (utilizable) Ln affect metabolism have rarely been done. We noticed unexpectedly pronounced changes in gene expression caused by different Ln supplementation. Our research suggests that strain RH AL1 distinguishes different Ln elements and that the effect of Ln reaches into many aspects of metabolism, for instance, chemotaxis, motility, and polyhydroxyalkanoate metabolism. Our findings regarding Ln accumulation suggest a distinction between individual Ln elements and provide insights relating to intracellular Ln homeostasis. Understanding comprehensively how microbes distinguish and handle different Ln elements is key for turning knowledge into application regarding Ln-centered biometallurgy.

Examining the effect of lanthanide-contaminated wastes, which have the potential to impact to other environmental compartments, requires conducting interaction studies with soils, as feasible first receptors of lanthanide leachates, and, if necessary, with sorbent materials, such as clay minerals and carbon-rich materials, which can serve as natural barriers and immobilisation agents used in remediation strategies. In this context, it is relevant to have available and reliable data on solid–liquid distribution coefficients (Kd) to understand the lanthanide sorption in these environmental matrices. Moreover, confirming lanthanide sorption analogies permits filling data gaps and data extrapolation among different contaminated scenarios, and thus facilitate to have available input data for decision-making related to the impact of a contaminated site. In this study, we demonstrate for the first time an analogous sorption of La, Sm, and Lu in carbon-rich materials (i.e., biochar and activated charcoal), clay minerals and soils, through laboratory batch experiments. The obtained sorption Kd values revealed similar sorption patterns among the three lanthanides for each matrix tested, even at different initial lanthanide concentrations. In all matrices, the maximum Kd values exceeded 104 L kg−1, with a significant decrease when testing high lanthanide concentrations. The analogy was first confirmed by examining the Kd correlations for the La-Sm, Lu-Sm, and La-Lu pairs within each matrix, for which strong linear correlations were obtained in all cases. Data compilations were built with own and literature data, and derived cumulative distribution functions revealed statistically equal lanthanide distributions and Kd best estimates. In addition to this, Kd variability decreased when grouping the data according to significant material properties. For the first time, Kd (Ln) best-estimates for different scenarios and materials were proposed as input data for risk assessment models.

Two compounds, Na3[Eu(DPA)3] ⋅ 14H2O and [Eu(DPA)(HDPA)(H2O)2] ⋅ 4H2O, were created and the structure determined using single crystal X‐ray diffraction. The single crystal luminescence properties were compared and related to the Eu3+ coordination geometry. The formation of single crystals from solutions of Eu(CF3SO3)3 and H2DPA was found change with the pH value of the H2DPA solution. Mixtures of Na3[Eu(DPA)3] ⋅ 14H2O and [Eu(DPA)(HDPA)(H2O)2] ⋅ 4H2O were observed with a pH ratio between the two structures. While visual inspection showed that all samples contained both Na3[Eu(DPA)3] ⋅ 14H2O and [Eu(DPA)(HDPA)(H2O)2] ⋅ 4H2O, the PXRD and luminescence data did not immediately reveal that the samples were pure. Having discovered that the samples were indeed mixtures, quantification was attempted by Rietveld refinement of the PXRD data, and the luminescence spectra were compared to those from single crystals. As the data was not found to reveal that the samples were mixtures, even though we knew that this was the case, we must urge caution when inferring structure‐property relationships from powder samples. In this case we were able to isolate monophasic systems and do a comparative study, but this requires that the samples are identified as mixtures. [ABSTRACT FROM AUTHOR]

The first use of the Schiff base chelate N‐naphthalidene‐o‐aminophenol (naphH2) in Co/Ln chemistry has afforded a family of isostructural [CoIII2LnIII(OMe)2(naph)2(O2CMe)3(MeOH)2] (Ln=Tb, Dy and Er) complexes, revealing a rare {CoIII2Ln(μ3‐OMe)}8+ triangular core composed of two diamagnetic CoIII ions and a 4f‐ion with slightly distorted square antiprismatic geometry. Alternating current (ac) magnetic susceptibility studies revealed that {Co2Dy}, and its magnetic diluted analogue {Co2Dy0.05Y0.95}, behave as mononuclear single‐molecule magnets (SMMs) with similar energy barriers for the magnetization reversal, Ueff, of ~85‐90 K. SMM properties were also detected for {Co2Er}, with the compound exhibiting a Ueff of 18.7 K under an applied magnetic field of 800 Oe. To interpret the experimental magnetic results, ab initio CASSCF/RASSI‐SO and DFT calculations were performed as a means of exploring the single‐ion characteristics of LnIII ions and comprehend the role of the diamagnetic CoIII ions in the magnetization relaxation of the three heterometallic compounds. [ABSTRACT FROM AUTHOR]

A series of isostructural Ln3O2(CN3) (Ln=La, Eu, Gd, Tb, Ho, Yb) oxoguanidinates was synthesized under high‐pressure (25–54 GPa) high‐temperature (2000–3000 K) conditions in laser‐heated diamond anvil cells. The crystal structure of this novel class of compounds was determined via synchrotron single‐crystal X‐ray diffraction (SCXRD) as well as corroborated by X‐ray absorption near edge structure (XANES) measurements and density functional theory (DFT) calculations. The Ln3O2(CN3) solids are composed of the hitherto unknown CN35− guanidinate anion—deprotonated guanidine. Changes in unit cell volumes and compressibility of Ln3O2(CN3) (Ln=La, Eu, Gd, Tb, Ho, Yb) compounds are found to be dictated by the lanthanide contraction phenomenon. Decompression experiments show that Ln3O2(CN3) compounds are recoverable to ambient conditions. The stabilization of the CN35− guanidinate anion at ambient conditions provides new opportunities in inorganic and organic synthetic chemistry. [ABSTRACT FROM AUTHOR]

Renewable and biodegradable polysaccharides have attracted interest for their wide applicability, among them their use as sorbents for heavy metal ions. Their high sorption capacity is due mainly to the acidic groups that populate the polysaccharide backbone, for example, carboxylic groups in alginate and sulfate ester groups in the iota and lambda carrageenans. In this study, these three polysaccharides were employed, alone or in different mixtures, to recover different heavy metal ions from aqueous solutions. All three polysaccharides were capable of adsorbing Eu3+, Sm3+, Er3+, or UO22+ and their mixtures, findings that were also confirmed using XPS, TGA, and FTIR analyses. In addition, the highest sorption yields of all the metal ions were obtained using alginate, alone or in mixtures. While the alginate with carboxylic and hydroxyl groups adsorbed different ions with the same selectivity, carrageenans with sulfate ester and hydroxyl groups exhibited higher adsorption selectivity for lanthanides than for uranyl, indicating that the activity of the sulfate ester groups toward trivalent and smaller ions was higher. [ABSTRACT FROM AUTHOR]

Using Ce(III) as both a representative lanthanide and actinide analog, the ability of mixtures of acidic and basic azoles to allow direct access to homoleptic N‐donor f‐element complexes in one pot reactions from hydrated salts as starting materials was examined by reacting mixtures of 4‐amino‐1,2,4‐triazole (4‐NH2‐1,2,4‐Triaz), 5‐amino‐tetrazole (5‐NH2‐HTetaz), and 1,2,3‐triazole (1,2,3‐HTriaz) in 1 : 1 and 1 : 3 ratios with CeCl3 ⋅ 7H2O, [C2mim]3[CeCl6] ([C2mim]+=1‐ethyl‐2‐methylimidazolium), and Ce(NO3)3 ⋅ 6H2O. Although unsuccessful in our goal, structural analysis revealed that neutral 4‐NH2‐1,2,4‐Triaz is structure directing via η2μ2κ2 bridging, with the formation of the dinuclear complexes [Ce2Cl2(μ2‐4‐NH2‐1,2,4‐Triaz)4(H2O)8]Cl4 ⋅ 4H2O, [Ce2(μ2‐4‐NH2‐1,2,4‐Triaz)4(4‐NH2‐1,2,4‐Triaz)2(Cl)6], and [4‐NH2‐1,2,4‐HTriaz][Ce2(μ2‐4‐NH2‐1,2,4‐Triaz)2(μ2‐NO3)(NO3)6(H2O)2]. When the synthetic conditions favored hydrolysis, the hexanuclear Ce(III) complex [Ce6(μ3‐O)4(μ3‐OH)2(μ3‐Cl)2(Cl)6(μ2‐4‐NH2‐1,2,4‐Triaz)12] ⋅ 7H2O was isolated. This unexpected hydrolysis product represents the first example of a high nuclearity lanthanide complex where all Ln atoms are pairwise connected through 12 N‐donor ligands or 12 neutral bridging ligands of any type, a rare example of incorporation of non‐oxo coordinating anions in the M6X8 core, and the first reported Ce(III) hexanuclear complex of this type. [ABSTRACT FROM AUTHOR]

The magnetic susceptibility is measured for two series of linear organic–inorganic coordination polymers I‐Ln and II‐Ln (Ln = La–Tb). The structure of the polymers (isostructural in each series I‐Ln and II‐Ln) differs in the length and structure of the bridges and in the nearest environment of the lanthanides. The effective magnetic moments of lanthanide atoms are determined from the magnetic susceptibility. The measured magnetic moments agree with the values characteristic of isolated trivalent 3+ ions for all cases, except for Tb which demonstrates a higher value of 12.25 μB in one of the complexes. An analysis of the X‐ray photoelectron spectrum of Tb 5s makes it possible to estimate the spin magnetic moment of the Tb ion. [ABSTRACT FROM AUTHOR]

The paper of van der Ent et al. (Plant Soil 485:247–257, 2023), published in the previous issue, reports the hyperaccumulation of rare earth elements (REE) in plant species from the Proteaceae for the first time. Indeed, the high REE accumulation in Proteaceae is not completely unexpected, given that the plants release large amounts of carboxylates to acquire phosphorus and micronutrients. However, it is somewhat questionable that the efficiency of element mobilization alone sufficiently explains the large variability in REE accumulation among different taxa of Proteaceae or other P-efficient species that typically show low concentrations of REE. Given that REE3+ share chemical similarities to Ca2+ but form stable complexes with ligands similar to Al3+, it is reasonable that uptake and accumulation of REE depend not solely on element mobility but also on the dynamics of element speciation governed by the formation, stability, and fate of carboxylate-REE-complexes in the rhizosheaths. The rationale behind this contention is that for elements with low mobility in soil, changes in chemical speciation may increase the availability only if the complex stabilities that depend on rhizosphere pH allow a breakdown during uptake. In this commentary, we explore the idea that REE accumulation depends on rhizosphere processes related to nutrient acquisition and element exclusion that overlap in time, space, and function depending on the composition of metal-chelating ligands released by plant roots in concert with rhizosphere pH. Based on data from greenhouse and field experiments, we propose a model where plants with a P-mining strategy (hyper)accumulate REE when rhizosphere pH is below a critical value shifting the REE speciation to available forms. [ABSTRACT FROM AUTHOR]

The combination of two neutral CHON reagents, a lipophilic phenanthroline dicarboxamide and a hydrophilic diglycolamide, resulted in a synergistic separation of adjacent light lanthanides in nitrate medium as the ligands present a reversed lanthanide selectivity. Separation factors higher than 7 were obtained for the pair Pr/Nd, which is one of the highest values reported in the literature. [ABSTRACT FROM AUTHOR]

Taguchi method was applied to determine the optimum conditions for the extraction and separation of some lanthanides using three organic extractants. It was found that the optimum results were obtained with trioctylphosphine oxide (TOPO). The extraction efficiency and distribution coefficient of La(III), Ce(III), Y(III) and Th(IV) increased by increasing the salt concentration. Under these conditions 1 M HNO3, 0.1 M TOPO and 10–1 M KSCN, the extraction efficiency of all metals reached 85%. Based to the Pourbaix diagrams La3+, Ce3+, Y3+ and Th4+ were formed and the stoichiometry of the extracted complexes were Ln NO 3 3 · 2 TOPO org and Th NO 3 4 · TOPO org . [ABSTRACT FROM AUTHOR]

Electrospray Ionization Mass Spectrometry (ESI‐MS) technique and density functional theory (DFT) calculations were combined to study the formation of the complexes of lanthanides (Ln = La, Ce, Nd, Sm, Eu, Yb) and actinides (UO22+, Th4+) with CyMe4‐BTBP (6,6′‐bis(5,5,8,8‐tetramethyl‐5,6,7,8‐tetrahydro‐benzo‐[1,2,4‐]triazin‐3‐yl)‐[2,2′]bipyridine) to understand the mechanisms during the extraction process. Mass spectrometry titrations showed the formation of the complexation in acetonitrile. For lanthanides, only 1:2 complexes ([Ln(L)2]3+, [Ln(L)2(CH3CN)]3+), [Ln(L)2(NO3)]2+) were found at low [Ln]/[L] concentration ratios, whereas the 1:1 complexes ([Ln(L)(NO3)2]+) were observed when the [Ln]/[L] concentration ratio reached 1.0. For uranyl complexes, 1:1 complex ([UO2L(NO3)]+) was the only species within the measuring range. Th4+ complexes had two compositions: 1:1 and 1:2, in which 1:2 species was the dominant complex. Collision‐induced dissociation (CID) was employed to characterize the fragmentation process. The fragmentation process was unfolded sequentially on both sides of CyMe4‐BTBP ligand with the loss of alkyl groups and cleavage of triazinyl rings. The CID results of CyMe4‐BTBP complexes revealed a slight difference depending on the metal center. The DFT calculations showed that the stable complexes formed in acetonitrile solution were consistent with the ESI‐MS results. [ABSTRACT FROM AUTHOR]

Effect of structure of phosphorylketones containing flexible alkyl and conformationally rigid fragments in the linker on extraction ability toward actinides and lanthanides has been studied. It has been shown that the introduction of conformationally rigid cycloalkanediyl and alkenediyl fragments in the bridge between P=O and C=O groups in the structure of molecule decreases efficiency of extractants for both actinides and lanthanides. At the same time, the introduction of flexible alkyl groups in linker structure increases complexing and extraction ability. This dependence has been explained theoretically by modeling complexation (DFT, PBE, cc-pVDZ), monodentate coordination was observed for all studied phosphorylalkanones [ABSTRACT FROM AUTHOR]

Lanthanide-doped nanoparticles, featuring sharp emission peaks with narrow bandwidth, exhibit high downconversion luminescence intensity, making them highly valuable in the fields of bioimaging and drug delivery. High-crystallinity Y2O3 nanoparticles (NPs) doped with Er3+ ions were functionalized by using a pegylation procedure to confer water solubility and biocompatibility. The NPs were thoroughly characterized using transmission electron microscopy (TEM), inductively coupled plasma mass spectrometry (ICP-MS), and photoluminescence measurements. The pegylated nanoparticles were studied both from a toxicological perspective and to demonstrate their internalization within HCT-116 cancer cells. Cell viability tests allowed for the identification of the "optimal" concentration, which yields a detectable fluorescence signal without being toxic to the cells. The internalization process was investigated using a combined approach involving confocal microscopy and ICP-MS. The obtained data clearly indicate the efficient internalization of NPs into the cells with emission intensity showing a strong correlation with the concentrations of nanoparticles delivered to the cells. Overall, this research contributes significantly to the fields of nanotechnology and biomedical research, with noteworthy implications for imaging and drug delivery applications. [ABSTRACT FROM AUTHOR]

We report the synthesis of a new pyrene, dipicolinic acid‐based ligand (L1H) and its corresponding multi‐emissive and multifunctional europium complex [Eu(L1)3] that is capable of single component color switchable emission from red to blue and also white. At high concentration (10 mM) the single component system results in near pure white emission (CIE coordinates x,y=0.329, 0.324). Furthermore, the system showed ratiometric oxygen sensing with oxygen significantly quenching the pyrene centered emission but not the Eu3+ emission, resulting in an overall emission color change from blue to red on increasing oxygen content. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The reaction of DyCl3⋅6H2O with a rigid diacylhydrazone ligand (H2L) afforded a trinuclear precursor [Dy3L2Cl3(H2O)2(CH3OH)]Cl2⋅3CH3OH (1). The replacement of the Cl– ions and the coordinating solvents by the aryloxides ligands (Lx)– yields three trinuclear complexes [Dy3L2(Lx)5]⋅nsol (x = 1,2‐naphthol (2); x = 2,7‐hydroxycoumarin (3); and x = 3, phenol (4)). In complexes 2—4, two end Dy3+ centers adopt almost identical N4O4 coordination sphere of D6h geometry while the central one adopts N4O5 coordination sphere in Cs geometry. Magnetic measurements reveal weak antiferromagnetic interactions in the hydrated samples 2e—4e and two‐step slow relaxation process under zero dc field with effective energy barriers Ueff of 439 and 91 K, 353 and 40 K, 466 and 89 K for SR and FR in 2e—4e, respectively. Such dynamic magnetic behaviour for 4 persists in the magnetically diluted sample of 4@Y. Complex 4 possesses the short Dy‐Oaryloxide bond distance of 2.055(18) Å, and the largest Ueff among the reported linear trinuclear dysprosium complexes. Moreover, the functionalized aryloxides ligands (Lx)– show photoluminescence via intramolecular energy transfer, making 2e—4e luminescent Dy3+ SMMs with high energy barriers. [ABSTRACT FROM AUTHOR]

In recent years, bis‐1,2,4‐triazine ligands have been widely used in actinide separation processes for their good separation ability and stability in high acidity. However, the hard stripping of BTP, kinetics sluggish of BTBP, and inexhaustive separation of BTPhen are still issues to be improved. Here, we evaluated the effects of bis‐1,2,4‐triazine ligands containing 6‐membered aliphatic rings L1‐3 and bis‐1,2,4‐triazine ligands containing 5‐membered aliphatic rings L4‐6 on selective separation of Am(III)/Eu(III) to understand the structure‐effect relationship of ligands (skeleton of pyridine L1,4, bipyridine L2,5, and phenanthroline L3,6). Six bis‐1,2,4‐triazine ligand structures are optimized based on density function theory(DFT). Herein, complexations of L2, L3L5L6 with Am/Eu ions were investigated. The results show that all BTPs ligands preferentially bind to Am(III). The electronic structures of the [M(L)2(NO3)]2+ (M = Am, Eu) complex and the bonding properties between metal and ligand were investigated. The results suggest that phenanthroline containing six‐membered aliphatic rings L3 shows the best affinity for Am(III) and phenanthroline containing five‐membered aliphatic rings L6 show faster dynamics. The calculated thermodynamic and separation factors indicate that L6 has the best selective separation of Am(III)/Eu(III). In conclusion, the skeleton of phenanthroline has the best extraction effect on Am(III), while the kinetics and separation effect can be improved by adjusting aliphatic rings. [ABSTRACT FROM AUTHOR]

Reactions in the Na2MoO4–ZrOCl2–ErCl3–H2O system at 20°C were studied by the method of residual concentrations. The insoluble substance formed in this system was investigated by physicochemical methods (XRD, IR spectroscopy, thermal analysis). [ABSTRACT FROM AUTHOR]

Remote temperature probing at the cryogenic range is of utmost importance for the advancement of future quantum technologies. Despite the notable achievements in luminescent thermometers, accurately measuring temperatures below 10 K remains a challenging endeavor. In this study, we propose a novel magneto‐optical thermometric approach based on the magnetic‐circular dichroism (MCD) technique, which offers unprecedented capabilities for meticulous temperature variation analysis at cryogenic temperatures. The inherent temperature sensitivity of the MCD C‐term, in conjunction with both positive and negative signals, enables highly sensitive magneto‐optical temperature probing. Additionally, a groundbreaking relative thermal sensitivity value of 95.3 % K−1 at 2.54 K can be achieved using a mononuclear lanthanide complex, [[Ho(acac)3(phen)], in the presence of a 0.25 T applied magnetic field and using a combination of multiparametric thermal read‐out with multiple regression. These results unequivocally demonstrate the viability and effectiveness of our methodology for cryogenic temperature sensing. [ABSTRACT FROM AUTHOR]

Materials based on organic chromophores and lanthanides able to transform low‐energy photons, specifically near‐infrared (NIR) photons, into higher energy photons to eventually lead to long‐lived sensitized emission of the dye are highly desirable. Cooperative sensitization (CS) upconversion has only been accomplished for lanthanide‐based clusters. We used here the eosin Y (EOS) dianion and Yb3+ (EOS‐Yb), and demonstrate the efficient CS emission of the dye after NIR excitation. Remarkably, the EOS dianion emission exhibits a nearly linear dependence on the EOS‐Yb concentration and a quadratic dependence on the laser power density. The emission is non‐sensitive to oxygen and its lifetime lasts about 1.76 μs and 12 μs in DMSO and DMSO‐d6, respectively. Moreover, the effect of temperature (293–363 K range) on the EOS‐Yb 1H NMR spectroscopic shifts demonstrates the reversible dynamic nature of the material. [ABSTRACT FROM AUTHOR]

A gradient elution-based ion interaction chromatography (IIC) method was developed for the determination of trace terbium (Tb) in a gadolinium (Gd) matrix. A reverse-phase column dynamically coated with camphor sulfonic acid (CSA) and α-hydroxybutyric acid (α-HIBA) as the eluent was utilized. Through a comprehensive study, an optimized gradient profile was established, which improved the separation between Tb and Gd. The limit of detection (LOD) for Tb was 2 ng/mL, and the standard deviation was 2% (n = 3) for 0.1 µg/mL Tb in the presence of 1084 µg/mL Gd. With the developed method, trace Tb determination without prior matrix separation was possible. [ABSTRACT FROM AUTHOR]

Luminescent lanthanide (Ln3+ = Pr, Nd, Sm, Eu, and Tb)-ions doped calcium molybdate(CaMoO4) nanoparticles(NPs) were prepared by the polyol wet-chemical route. X-ray diffraction (XRD) pattern of all samples showed the formation of a single-phase scheelite type tetragonal structure with an average crystalline size over 21.6–33.4 nm. Thermal stability was evaluated to study the surface-anchored functional groups by weight loss measurement. Fourier transform infrared (FTIR) spectra were recorded to identify the adsorbed functional groups. Aqueous dispersibility and colloidal stability were recorded with the help of the UV/visible absorption spectra. These nanocrystals formed semi-transparent colloidal solutions after being evenly disseminated in aqueous media. The doping of the luminescent ions significantly affects the crystal structure and photoluminescence (PL) properties of the CaMoO4:Ln3+ NPs. In a comparative analysis of the absorption spectra, bandgap, Raman-active modes, and luminescent properties, they were greatly influenced by altering the dopant ion due to the variation in the atomic radius of the element. The doping of smaller atomic radius Ln3+-ions distorts the unit cell, and, subsequently, bond angle/length alters the symmetry of the host crystal. The distorted crystal lattice affects the crystalline, size, lattice parameter, band gap values, Raman active vibrational modes, and luminescent efficiency. The distorted crystal structure of the host lattices facilitates the movement of the oxygen vacancies through charge transfer, resulting in efficiently suppressed emission efficiency. Graphical abstract [ABSTRACT FROM AUTHOR]

The synthesis of new water-soluble N-alkylated derivatives of 1,3,5-triaza-7-phosphaadamantane is presented. Ru(PPh3)2Cl2 has been used to react with 1-(4-nitrobenzyl)-3,5-triaza-1-azonia-7-phosphaadamantane bromide (PTAR). By using elemental analysis, NMR, and IR spectroscopy, the obtained compounds were identified. The UV-visible absorption spectroscopy has been used to monitor the complexation of various transition metal cations. Studies on conductivity have been utilized to validate the complexes' stoichiometries. Using the disc diffusion method, five bacteria strains were used for the study of the antimicrobial activity of compounds 1-3. All tested pathogens, including M luteus LB 141107, were found to have strong biologic activity against the compounds tested in this study. Additionally, DPPH (2,2-diphenyl-1-picrylhydrazyl) has been tested for its ability to scavenge hydrogen peroxide and free radicals. According to our results, these compounds exhibit excellent radical scavenging properties. [ABSTRACT FROM AUTHOR]

The oxidation states of atoms in CuCr1-xLaxS2 (x = 0–0.03) solid solutions were determined using the analysis of Cu2p, Cr2p, S2p, and La3d core level binding energy. The cationic substitution did not significantly affect the charge distribution on matrix elements (Cu, Cr, and S). The oxidation states of the atoms were identified as S2− for sulfur, Cu+ for copper, and Cr3+ for chromium. The cationic substitution in CuCr1-xLaxS2 was found to occur via the isovalent principle. The cationic substitution of CuCrS2 matrix with lanthanum ions led to the enhancement of the Seebeck coefficient comparing CuCr1-xLaxS2 to the initial matrix. The observed enhancement was attributed to the reconstruction of the valence band electronic structure after the cationic substitution. The maximum Seebeck coefficient value of 412 μV/K was measured for CuCr0.985La0.015S2 at 420 K. An increase in the lanthanum concentration to x = 0.03 caused a suppression of the Seebeck coefficient. The synthetic route was found to significantly affect both the magnetic properties and charge carrier concentration. The magnetic properties of CuCr1-xLaxS2 synthesized using metal sulfide reagents cannot be interpreted using the simple isovalent Cr3+ to La3+ cationic substitution model. The defectiveness of the samples and the formation of the impurity CuLaS2 phase could be additional factors that affect the magnetic properties of CuCr1-xLaxS2. [ABSTRACT FROM AUTHOR]

Different energy interaction parameters such as Slater–Condon (Fk), Racah (Ek) factor, Lande (ξ4f) parameter, nephelauxetic ratio (β), bonding parameter (b1/2), and percent covalency parameter () were evaluated for the 4f–4f transition spectra of free and complexed Nd3+ ion with the amino acid ligands namely L-tryptophan and L-isoleucine. The experiment was conducted in different aquated organic solvents (dimethylformamide, acetonitrile, 1,4-dioxane, and methanol) in the presence/absence of Mg2+, which was extended further at different pH (2, 4, and 6) in dimethylformamide medium. The calculated values of the energy interaction parameters could indicate the detailed fashion of binding of the ligand with the metal including its possible coordination number theoretically. The complexation was found to be most favorable in DMF solvent and also at pH 6. [ABSTRACT FROM AUTHOR]

The triphenylmethane (trityl) group has been recognized as a supramolecular synthon in crystal engineering, molecular machine rotors and stereochemical chirality inductors in materials science. Herein we demonstrate for the first time how it can be utilized in the domain of molecular magnetic materials through shaping of single molecule magnet (SMM) properties within the lanthanide complexes in tandem with other non‐covalent interactions. Trityl‐appended mono‐ (HL1) and bis‐compartmental (HL2) hydrazone ligands were synthesized and complexated with Dy(III) and Er(III) triflate and nitrate salts to generate four monometallic (1–4) and two bimetallic (5, 6) complexes. The static and dynamic magnetic properties of 1–6 were investigated, revealing that only ligand HL1 induces assemblies (1–4) capable of showing SMM behaviour, with Dy(III) congeners (1, 2) able to exhibit the phenomenon also under zero field conditions. Theoretical ab initio studies helped in determination of Dy(III) energetic levels, magnetic anisotropic axes and corroborated magnetic relaxation mechanisms to be a combination of Raman and quantum tunnelling in zero dc field, the latter being cancelled in the optimum non‐zero dc field. Our work represents the first study of magneto‐structural correlations within the trityl Ln‐SMMs, leading to generation of slowly relaxing zero‐field dysprosium complexes within the hydrogen‐bonded assemblies. [ABSTRACT FROM AUTHOR]

In this study, we investigated the structures of lanthanide (Eu(III), Dy(III), and Gd(III)) complexes with p-coumaric (p-CAH2) and caffeic (CFAH3) acids using the FTIRKBr, FTIRATR, and Raman spectroscopic methods. The compositions of the solid phase caffeinates and p-coumarates were obtained on the basis of the amounts of hydrogen and carbon determined using an elemental analysis. The degree of hydration and the thermal decomposition of each compound were examined via a thermal analysis of TG, DTG, and DSC. Antioxidant spectroscopic tests were performed using the DPPH (1,1-diphenyl-2-picrylhydrazyl radical), FRAP (ferric reducing antioxidant activity), and ABTS (2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (diammonium salt radical cation) methods. The antimicrobial activity of each compound against Escherichia coli, Bacillus subtilis, and Candida albicans was investigated. The electrical properties of the liposomes which mimicked the microbial surfaces formed in the electrolyte containing the tested compounds were also investigated. The above biological properties of the obtained complexes were compared with the activities of p-CAH2 and CFAH3. The obtained data suggest that lanthanide complexes are much more thermally stable and have higher antimicrobial and antioxidant properties than the ligands (with the exception of CFAH3 in the case of antioxidant activity tests). The Gd(III) complexes revealed the highest biological activity among the studied lanthanide complexes. [ABSTRACT FROM AUTHOR]

Two-dimensional layered coordination polymers based on the hetero-substituted 3-chloro-6-cyano-2,5-dihydroxybenzoquinone ligands, hereafter ClCNAn2− anilate, and LnIII ions (Tb and Eu) are reported. Compounds 1 and 2, formulated as Ln2(ClCNAn)3(DMSO)6 (LnIII = Tb, 1; Eu, 2), and their related intermediates 1′ and 2′, formulated as Ln2(ClCNAn)3(H2O)x·yH2O (x + y likely = 12, Ln = Tb, 1′; and Eu, 2′), were prepared by a conventional one-pot reaction (the latter) and recrystallized from DMSO solvent (the former). Polyhydrated intermediates 1′ and 2′ show very similar XRPD patterns, while, despite their common stoichiometry, 1 and 2 are not isostructural. Compound 1 consists of a 2D coordination framework of 3,6 topology, where [Tb(DMSO)3]III moieties are bridged by three bis-chelating ClCNAn2− ligands, forming distorted hexagons. Ultrathin nanosheets of 1 were obtained by exfoliation via the liquid-assisted sonication method and characterized by atomic force microscopy, confirming the 2D nature of 1. The crystal structure of 2, still showing the presence of 2D sheets with a "hexagonal" mesh and a common (3,6) connectivity, is based onto flat, non-corrugated slabs. Indeed, at a larger scale, the different "rectangular tiles" show clear roofing in 1, which is totally absent in 2. The magnetic behavior of 1 very likely indicates depopulation of the highest crystal-field levels, as expected for TbIII compounds. [ABSTRACT FROM AUTHOR]

The possibility to precisely control reaction outcomes for pursuing materials with well-defined features is a main endeavor in the development of inorganic materials. Confining reactions within a confined space, such as nanoreactors, is an extremely promising methodology which allows to ensure control over the final properties of the material. An effective room temperature inverse miniemulsion approach for the controlled synthesis of undoped and Eu3+-doped calcium molybdate crystalline nanophosphors was developed. The advantages and the efficiency of confined space in terms of controlling nanoparticle features like size, shape, and functional properties are highlighted by systematically comparing miniemulsion products with calcium molybdate particles obtained without confinement from a typical batch synthesis. A relevant beneficial impact of space confinement by miniemulsion nanodroplets is observed on the control of size and shape of the final nanoparticles, resulting in 12 nm spherical nanoparticles with a narrow size distribution, as compared to the 58 nm irregularly shaped and aggregated particles from the batch approach (assessed by TEM analysis). Further considerable effects of the confined space for the miniemulsion samples are found on the doping effectiveness, leading to a more homogeneous distribution of the Eu3+ ions into the molybdate host matrix, without segregation (assessed by PXRD, XAS, and ICP-MS). These findings are finally related to the photoluminescence properties, which are evidenced to be closely dependent on the Eu3+ content for the miniemulsion samples, as an increase of the relative intensity of the direct f–f excitation and a shortening of the lifetime (from 0.901 ms for 1 at. % to 0.625 ms for 7 at. % samples) with increasing Eu3+ content are observed, whereas no relationship between these parameters and the Eu3+ content is evidenced for the batch samples. All these results are ascribed to the uniform and controlled crystallization occurring inside each miniemulsion nanodroplet, as opposed to the less controlled nucleation and growth for a classic nonconfined approach. [ABSTRACT FROM AUTHOR]

The surface chemistry of nanoparticles is a key step on the pathway from particle design towards applications in biologically relevant environments. Here, a bilayer‐based strategy for the surface modification of hydrophobic nanoparticles is introduced that leads to excellent colloidal stability in aqueous environments and good protection against disintegration, while permitting surface functionalization via simple carbodiimide chemistry. We have demonstrated the excellent potential of this strategy using upconversion nanoparticles (UCNPs), initially coated with oleate and therefore dispersible only in organic solvents. The hydrophobic oleate capping is maintained and a bilayer is formed upon addition of excess oleate. The bilayer approach renders protection towards luminescence loss by water quenching, while the incorporation of additional molecules containing amino functions yields colloidal stability and facilitates the introduction of functionality. The biological relevance of the approach was confirmed with the use of two model dyes, a photosensitizer and a nitric oxide (NO) probe that, when attached to the surface of the UCNPs, retained their functionality to produce singlet oxygen and detect intracellular NO, respectively. We present a simple and fast strategy to protect and functionalize inorganic nanoparticles in biological media, which is important for controlled surface engineering of nanosized materials for theranostic applications. [ABSTRACT FROM AUTHOR]

Chemotherapy‐induced enteritis is one of the side effects associated with cancer therapy, which significantly affects the treatment effect, but there is no effective clinical detection method that can early diagnose its occurrence and progression. Here, a series of second near‐infrared window (NIR‐II) hybrid nanosensors are designed that consisted of lanthanide nanoparticles and β‐Mo2C‐derived polymetallic oxomolybdate nanoclusters (Ln@POM). Based on the high sensitivity of POM to reactive oxygen species (ROS) closely related to chemotherapy‐induced enteritis, the NIR‐II luminescence intensity and lifetime of Ln@POM (Ln: Yb3+, Nd3+, Ho3+, Tm3+, Er3+) show excellent responsiveness to H2O2 and HClO with the detection limit down to 0.15 and 0.14 µm, respectively. Utilizing Nd@POM as a ROS‐activated NIR‐II nanosensor, the chemotherapeutic enteritis is successfully detected within 7 h after induction of chemotherapy drugs, which is significantly earlier than the gold standard method (immunohistochemistry, 24 h). These results demonstrate that the designed hybrid nanosensors are promising optical tools for the early diagnosis of ROS‐related diseases. [ABSTRACT FROM AUTHOR]

Abstract—First results of the experimental study of a hydrothermal multisystem including lanthanides (Ln) and Fe oxides (magnetite and hematite) are presented. Ln concentrations in solutions and crystals were determined by ICP-MS and LA-ICP-MS, respectively. The Ln partition and cocrystallization coefficients obtained are interpreted as the maximum estimates of "true" values corresponding to structurally bound admixture. It is shown that Ln (except for Eu) are the compatible elements in hydrothermal magnetite; heavy Ln (beginning with Tb) are compatible in hematite. The pronounced tendency of the increase of both coefficients with increasing Ln atomic number beginning from Gd–Tb was established. This is of great importance when light to heavy Ln ratio is used as a typochemical guide for localization of ore source. The Ln-rich phases in association with magnetite and hematite were obtained. These phases have oxychloride (without Fe) and oxyhydroxide (with Fe) composition and exemplify the simultaneous occurrence of light and heavy Ln within a single hydrothermal system due to the co-crystallization of phases selectively accumulating light and heavy lanthanides. [ABSTRACT FROM AUTHOR]

We report the synthesis of Ln3+ nitrate [Ln(Tpm)(NO3)3] ⋅ MeCN (Ln=Yb (1Yb), Eu (1Eu)) and chloride [Yb(Tpm)Cl3] ⋅ 2MeCN (2Yb), [Eu(Tpm)Cl2(μ‐Cl)]2 (2Eu) complexes coordinated by neutral tripodal tris(3,5‐dimethylpyrazolyl)methane (Tpm). The crystal structures of 1Ln and 2Ln were established by single crystal X‐ray diffraction, while for 1Yb high resolution experiment was performed. Nitrate complexes 1Ln are isomorphous and both adopt mononuclear structure. Chloride 2Yb is monomeric, while Eu3+ analogue 2Eu adopts a binuclear structure due to two μ2‐bridging chloride ligands. The typical lanthanide luminescence was observed for europium complexes (1Eu and 2Eu) as well as for terbium and dysprosium analogues ([Ln(Tpm)(NO3)3] ⋅ MeCN, Ln=Tb (1Tb), Dy (1Dy); [Ln(Tpm)Cl3] ⋅ 2MeCN, Ln=Tb (2Tb), Dy (2Dy)). [ABSTRACT FROM AUTHOR]

The responsive control of energy transfer (ET) plays a key role in the broad applications of lanthanide‐doped nanomaterials. Photonic crystals (PCs) are excellent materials for ET regulation. Among the numerous materials that can be used to fabricate PCs, chiral nematic liquid crystals are highly attractive due to their good photoelectric responsiveness and biocompatibility. Here, the mechanisms of ET and the photonic effect of chiral nematic structures on ET are introduced; the regulation methods of chiral nematic structures and the resulting changes in ET of lanthanide‐doped nanomaterials are highlighted; and the challenges and promising opportunities for ET in chiral nematic structures are discussed. [ABSTRACT FROM AUTHOR]

A series of 32 heterometallic ionic complexes [CeNi6(Ala)12][(LnxCe1 –x)(NO3)3(OH)3(H2O)] (Ln = Tb, Ho, Er, Tm, Yb, Lu) have been synthesized and characterized by XRD and IPC-MS. The dependence of the degree of substitution of lanthanides in the anionic position on the nature of Ln3+ and precipitation conditions has been determined. The processes occurring during the formation of the complexes have been studied by UV-Vis, diffuse reflectance electronic spectroscopy, and ICP-MS. Based on these data, a model of equilibria in the system was proposed to explain the increase in the degree of substitution of Ln in the anionic position in the lanthanide series and with a decrease in the concentration of Ce and Ln in the solution from which precipitation is performed. [ABSTRACT FROM AUTHOR]