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We report the results of measurements of thermal conductivity coefficient dependence on temperature of single crystals of SrIr4In2Ge4 and EuIr4In2Ge4. The measurements were carried out over the temperature range of ∼5–300 K. The EuIr4In2Ge4 crystal, unlike its strontium analog SrIr4In2Ge4, shows an amazing anisotropy: At low temperatures, it displays significantly smaller thermal conductivity in the ab plane than in the direction of c axis, while at the high ones the thermal conductivity in the direction perpendicular to the c axis increases well above that of in the c axis. The observed phenomena may be a result of the interaction of phonons with 1D chains of short-range ordered magnetic moment of europium atoms and the exchange energy between the chains in the paramagnetic phase of EuIr4In2Ge4. [ABSTRACT FROM AUTHOR]

Transition-metal and rare-earth borides are of considerable interest due to their electronic, mechanical, and magnetic properties as well as their structural stability under extreme conditions. Here, we report on a series of high-pressure Raman and x-ray diffraction experiments on the cubic rare-earth hexaboride EuB6 to an ultrahigh pressure of 187 GPa in a diamond anvil cell. In EuB6, divalent europium ions occupy the corners of the cubic structure, which encloses a rigid boron-bonded cage. So far, no structural phase transitions have been reported, while the nanoindentation studies indicate amorphization in nanoscale shear bands during plastic deformation. Our x-ray diffraction studies have revealed that the ambient cubic phase of EuB6 shows broadening and splitting of diffraction peaks starting at 72 GPa and the broadening continuing to 187 GPa. The high-pressure phase is recovered on decompression, and the Raman spectroscopy of the recovered sample from 187 GPa shows a downward frequency shift and broadening of T2g, Eg, and A1g modes of boron octahedron. The density functional theory simulations of EuB6 at 100 GPa have identified five possible lowest energy crystal structures. The experimental x-ray diffraction data at high pressures is compared with the theoretical predictions and the role of structural distortions induced by shear stresses is also discussed. [ABSTRACT FROM AUTHOR]

Polyvinylidene difluoride trifluoroethylene (PVDF-TrFE) has received widespread application in flexible electronics and biomedical devices but is limited in its sensing modalities to piezoelectricity and pyroelectricity. The addition of optically or magnetically active nanoparticles could provide additional sensing modalities in the same element, which could drive miniaturization of such sensors. Europium barium titanate (EBTO) is one such optically active nanoparticle that could add functionality to such a nanocomposite. In this work, multifunctional nanocomposites of PVDF-TrFE and EBTO are successfully synthesized and characterized for their material and electronic properties. The nanocomposite in this work is the first known multifunctional nanocomposite with PVDF-TrFE and a fluorescent nanoparticle. [ABSTRACT FROM AUTHOR]

A novel nanocomposite, [Eu(BTD)3(DPBT)]–BSA@MnO2, is reported to serve as an effective nanoprobe for bimodal time-gated luminescence (TGL) and magnetic resonance (MR) imaging of H2O2in vitro and in vivo. The nanoprobe was fabricated by immobilizing visible-light-excitable Eu3+ complexes in bovine serum albumin (BSA)-coated lamellar MnO2 nanosheets. The TGL of the Eu3+ complex was effectively quenched by the MnO2 nanosheets. Upon exposure to H2O2, the MnO2 nanosheets underwent reduction to Mn2+, which simultaneously triggered rapid, selective and sensitive "turn-on" responses toward H2O2 in both TGL and MR detection modes. The presence of a protective "corona" formed by BSA enables the nanoprobe to withstand high concentrations of glutathione (GSH), a strong reducing agent of MnO2 nanosheets. This capability allows the nanoprobe to be utilized for detecting H2O2 in living biosamples. The combined utilization of TGL and MR detection modes enables the nanoprobe to image H2O2 across a wide range of resolutions, from the subcellular level to the whole body, without any depth limitations. The results obtained from these modes can be cross-validated, enhancing the accuracy of the detection. The capability of the nanoprobe was validated by TGL imaging of endogenous and exogenous H2O2 in live HeLa cells, as well as bimodal TGL–MR imaging of H2O2 in tumor-bearing mice. The research achievements suggest that the integration of luminescent lanthanide complexes with protein-coated MnO2 nanosheets offers a promising bimodal TGL–MR sensing platform for H2O2in vitro and in vivo. [ABSTRACT FROM AUTHOR]

In this work, bisarsine oxides were evaluated as novel bridging ligands, aiming to develop practical and efficient luminescent lanthanide coordination polymers. We have synthesized one‐dimensional (1D) Eu3+ coordination polymers that incorporate bisarsine oxide bridging ligands and hexafluoroacetylacetonate anions. These polymers exhibited a denser packing of chains compared to analogous polymers bridged with bisphosphine oxides. The coordination polymers demonstrated exceptional thermal stability and substantial emission quantum yields. Additionally, the bisarsine oxides induced a pronounced polarization effect, facilitating a sensitive electric dipole transition that yields considerably narrow band red emission. Remarkably, the Eu3+ coordination polymers with bisarsine oxides maintained intense emission even at 550 K. A distinctive feature of these polymers is their heating‐induced emission enhancement observed when the temperature was increased from 300 K to 400 K. [ABSTRACT FROM AUTHOR]

Graphene‐like materials were prepared by thermal copolymerization using melamine as a precursor, and chemical methods successfully synthesized Eu/g‐C3N4 composites containing different europium elements. Degradation rates of 64.3 %, 91.9 %, and 72.8 % were observed in the photocatalytic degradation of Pefloxacin, Enrofloxacin, and Ciprofloxacin under visible light (λ>550 nm). Determine the photocatalytic activity of the composite. When the doping amount was Eu/g‐C3N4‐2 with k=0.0135 min−1, four times greater than that of g‐C3N4, the best photocatalytic effect was obtained. Repeated studies revealed that the Eu/g‐C3N4 composite samples had good cycle stability, and a potential degradation process was postulated. [ABSTRACT FROM AUTHOR]

Glasses with the compositions in mol % of 50ZnO:(50 − x)B2O3:0.5Eu2O3:xWO3, x = 0, 1, 3, 5 and 10 were obtained by applying the melt-quenching method and investigated by Raman spectroscopy, DSC analysis and photoluminescence (PL) spectroscopy. Raman spectra revealed that tungstate ions incorporate into the base zinc borate glass as tetrahedral [WO4]2− groups, and octahedral [WØ4O2]2− species with four bridging and two non-bridging oxygen atoms. There are also metaborate, [BØ2O]− and pyroborate units, [B2O5]4−, in the glass networks. The glasses are characterized by good transmission in the visible region, at about 80%. Photoluminescence (PL) spectra evidenced that WO3 is an appropriate constituent for the modification of zinc borate glass structure and for enhancing the Eu3+ luminescent intensity. The most intense luminescence peak observed, at 612 nm, suggests that the glasses are potential materials for red emission. [ABSTRACT FROM AUTHOR]

Efficient separation of europium (Eu) from aqueous solution is pivotal for the sustainable development of nuclear industry and rare earth industry. In this work, bis(2-ethylhexyl) phosphate (P204) was employed to separate Eu(III) by solvent extraction method using kerosene as diluent. The extraction equilibrium could reach within 30-min contact time. The extraction ratio enhanced as the increased O:A phase ratio, extractant concentration, and temperature. However, the HCl introduction caused its clear descent. Combined with the slope method and FT-IR analysis, extraction mechanism could be unveiled, which is the coordination between P=O double bond and Eu(III) ions in a proportion of 3:1. [ABSTRACT FROM AUTHOR]

This study explores the utilization of metal–organic frameworks (MOFs), particularly those incorporating lanthanide-based elements for their fluorescence capabilities, to create an advanced barcode system. By exploiting the modular nature of MOFs, we have developed a material capable of dynamic information encoding and robust against counterfeiting efforts. We introduce a novel barcode prototype that exhibits visible color shifts and fluorescence modulation when exposed to a specific sequence of chemical and thermal stimuli. The barcode is composed of MOF-808, which is modified with transition metals like iron or cobalt, and europium cations. These components are embedded within polyvinylidene fluoride (PVDF) to form a composite. This embedding process ensures that the MOF particles remain reactive to specific trigger molecules, enabling a distinct read-out sequence. The decoding process, involving exposure to ammonia, heating at 120 °C, and treatment with HCl, triggers observable changes in fluorescence and color, depending on the transition metal used. Our investigations with Eu,Co-MOF-808, and Eu,Fe-MOF-808 composites have resulted in the creation of a barcode prototype that demonstrates the feasibility of using europium-modified and unmodified transition metal modified MOF-808@PVDF composites for enhanced security applications. [ABSTRACT FROM AUTHOR]

The bulky β‐diketiminate ligand frameworks [BDIDCHP]− and [BDIDipp/Ar]− (BDI=[HC{C(Me)2N‐Dipp/Ar}2]− (Dipp=2,6‐diisopropylphenyl (Dipp); Ar=2,6‐dicyclohexylphyenyl (DCHP) or 2,4,6‐tricyclohexylphyenyl (TCHP)) have been developed for the kinetic stabilisation of the first europium (II) hydride complexes, [(BDIDCHP)Eu(μ‐H)]2, [(BDIDipp/DCHP)Eu(μ‐H)]2 and [(BDIDipp/TCHP)Eu(μ‐H)]2, respectively. These complexes represent the first step beyond the current lanthanide(II) hydrides that are all based on ytterbium. Tuning the steric profile of β‐diketiminate ligands from a symmetrical to unsymmetrical disposition, enhanced solubility and stability in the solution–state. This provides the first opportunity to study the structure and bonding of these novel Eu(II) hydride complexes crystallographically, spectroscopically and computationally, with their preliminary reactivity investigated. [ABSTRACT FROM AUTHOR]

The capacity to discern the highest temperature that an object is subjected to is a crucial diagnostic tool. Consequently, the pursuit of materials that enable the luminescence‐based investigation of the thermal history of an object with high sensitivity is of great importance from the functional applications standpoint. This study aims to present a multiparametric thermal history phosphor based on the luminescent coordination polymer [Eu(BTC)(H2O)6] [Eu(BTC)‐1, where H3BTC = 1,3,5‐benzenetricarboxylic acid]. The progressive dehydration that Eu(BTC)‐1 undergoes as a function of temperature increase in the 343–425 K range results in significant alterations in both the shape of the Eu3+ ions emission spectrum and the depopulation kinetics of their 5D0 level. Based on this occurrence, a thermal history phosphor with an unprecedentedly high relative sensitivity of 11.3% K−1 in ratiometric mode, and 1.8% K−1 in lifetime‐based mode, is developed. The outcomes of this research are expected to stimulate a wide interest in the exploitation of (porous) coordination polymer‐type materials for the development of thermal history phosphors. [ABSTRACT FROM AUTHOR]

Defects in phosphors affect not only luminescence intensity but also emission peak width, decay time, and afterglow. The green phosphor β -SiAlON:Eu2+ exhibits the green emission of Eu2+ at 520 nm and the blue emission of nitrogen vacancies at 460 nm in time-resolved fluorescence measurements. The decay time of the intrinsic Eu2+ transition is 0.7 μ s, but afterglow is detected from 50 μ s to 0.01 s. This afterglow decay curve is the same for the green emission of Eu2+ and the blue emission of nitrogen vacancies, suggesting that the defect levels of the nitrogen vacancies affect the Eu2+ transition. The afterglow decay curves were analyzed using the formula of the general-order kinetics, 1 + t / τ B − n , where n is the decay power and τ B is the decay time. This equation is generally used when analyzing afterglow on the order of seconds to hours but has not been examined systematically applied in samples with different concentrations of Eu2+ and temperatures on the order of nanoseconds to milliseconds. The decay power n is approximately 1 for all Eu2+ concentrations (x = 0.001–0.3) and undoped β -SiAlON. The decay time τ B is correlated with the density of the nitrogen vacancies determined by electron spin resonance. Furthermore, the value of n is approximately 1 for 50 μ s to 0.01 s and 0.3 for 1–1000 s. Thus, the luminescence mechanism of Eu2+ can be discussed by comparing n and τ B obtained from the decay curves. In addition, several different Eu2+-doped phosphors, namely SrAl2O4:Eu2+, Dy3+, CaAlSiN3:Eu2+, and CaS:Eu2+, Tm3+, are studied. [ABSTRACT FROM AUTHOR]

Simple Summary: The analysis of the toxicity of lanthanides, and among them europium, has grown in recent years due to its multiple applications in different human technologies. In the present research work, we analyze its toxicity in the eukaryotic microorganism model Tetrahymena thermophila, comparing strains adapted to high concentrations of two europium compounds (chloride and oxide forms) with the wild-type strain. The oxidative stress caused by europium oxide is reduced by overexpression of genes encoding various antioxidant enzymes. Similarly, metallothionein genes of this microorganism are overexpressed, which could indicate the possible chelation of this lanthanide by these proteins. Lipid metabolism and autophagy are involved in the cellular stress response to europium. Both bioaccumulation in vacuoles, and their subsequent release, as well as a possible biotransformation to europium phosphate are involved in the europium detoxification process in these cells. A better understanding of the cellular mechanisms of lanthanide detoxification is very useful information for solving bioremediation problems and possible intoxications in animals and humans. Europium is one of the most reactive lanthanides and humans use it in many different applications, but we still know little about its potential toxicity and cellular response to its exposure. Two strains of the eukaryotic microorganism model Tetrahymena thermophila were adapted to high concentrations of two Eu(III) compounds (EuCl3 or Eu2O3) and compared to a control strain and cultures treated with both compounds. In this ciliate, EuCl3 is more toxic than Eu2O3. LC50 values show that this microorganism is more resistant to these Eu(III) compounds than other microorganisms. Oxidative stress originated mainly by Eu2O3 is minimized by overexpression of genes encoding important antioxidant enzymes. The overexpression of metallothionein genes under treatment with Eu(III) compounds supports the possibility that this lanthanide may interact with the -SH groups of the cysteine residues from metallothioneins and/or displace essential cations of these proteins during their homeostatic function. Both lipid metabolism (lipid droplets fusing with europium-containing vacuoles) and autophagy are involved in the cellular response to europium stress. Bioaccumulation, together with a possible biomineralization to europium phosphate, seems to be the main mechanism of Eu(III) detoxification in these cells. [ABSTRACT FROM AUTHOR]

Thermometry of thermal barrier coatings (TBCs) is essential for designing effective thermal management systems and prolonging the service life of components in aeroengines and gas turbines. However, conducting on-line thermometry in these systems is challenging because it requires physical or optical access to components during operation. A promising alternative is off-line thermometry, in which phosphorescent thermal-history sensors are used to record exposure temperatures after operation. In this study, we synthesized europium (III)-ion-doped barium aluminate (BaAl 2 O 4 :Eu3+) via a solid-state reaction and confirmed its ability to function as a thermal history sensor. Subsequently, we developed a new thermal-sensing strategy based on the self-reduction of Eu3+ to Eu2+ in a BaAl 2 O 4 :Eu3+ phosphor exposed to high temperatures (900–1300 °C) in ambient air. The Eu3+ concentration decreased as the heat exposure temperature increased due to self-reduction of Eu3+ to Eu2+, which irreversibly changed the phosphorescence of BaAl 2 O 4 :Eu3+, i.e., its spectra, the ratio of the phosphorescence intensities of Eu3+ and Eu2+, and the lifetime of Eu3+. As the heat exposure temperature increased, the ratio of the phosphorescence intensities of Eu3+ and Eu2+ monotonically decreased due to self-reduction, whereas the phosphorescence lifetime of Eu3+ initially gradually increased until the heat exposure temperature reached 1000 °C because of the degeneration of concentration quenching, and then decreased as the temperature exceeded 1000 °C because of the degeneration of lattice distortions. This demonstrates that heat exposure temperatures exceeding 1000 °C can be quantitatively evaluated through off-line analysis of Eu3+ and Eu2+ phosphorescence intensity ratios and Eu3+ lifetime at room temperature. Thus, BaAl 2 O 4 :Eu3+, a self-reducing phosphor, is a potential sensor for off-line thermometry of TBCs. [ABSTRACT FROM AUTHOR]

The advancement of bioimaging and theranostics necessitates the development of highly biocompatible multifunctional agents. Here, we introduce a potential multimodal agent based on nanosized hydroxyapatite (HAp) co-doped with europium(III) and gadolinium(III) (Eu3+ and Gd3+) ions. The study presents a detailed characterization of the HAp:Eu3+/Gd3+ nanoparticles synthesized via the co-precipitation method. The structure and morphology were analyzed using X-ray powder diffraction (XRPD), transmission electron microscopy (TEM), and Fourier transform infrared (FT-IR) spectroscopy. The study of spectroscopic properties (emission, excitation, emission kinetics) as a function of optically active ions was carried out. Moreover, various dopant ratio combinations were studied to optimize the optical and magnetic properties. HAp:Eu3+/Gd3+ demonstrates tunable PL intensity with different concentrations of Eu3+ and Gd3+ ions and increased magnetization with higher doping with Gd3+ ions. Furthermore, co-doping with Gd3+ ions results in an enhancement of Eu3+ emission intensity, rendering HAp:Eu3+/Gd3+ a potentially promising candidate for bioimaging applications. [ABSTRACT FROM AUTHOR]

Lanthanides (Ln2O3) and elements like Zr and Y find application in the highest temperature‐resistant thermal and/or environmental barrier coatings. Such coatings are routinely exposed to silicate particles (e.g., sand, dust, volcanic ash), leading to chemical reactions that degrade the coating. The dissolution of 13.5 wt.% Ln2O3 into a calcium–magnesium–aluminum‐silicate (CMAS) melt leads to a viscosity reduction for the light lanthanides, while viscosity increases toward heavier lanthanides. For Gd, Y, and Zr, various amounts up to 13.5 wt.% (Gd2O3, Y2O3, ZrO2) were added to the CMAS melt, showing a tendency of increased viscosity for low concentrations (2.5‐3 wt.%) and a decreasing viscosity for higher values of the added component. [ABSTRACT FROM AUTHOR]

Europium (Eu) ion–doped luminescent materials have attracted considerable attention for their numerous optical applications. Eu‐doped Ca–Al–Si–O(–N) glasses were synthesized from a mixture of oxynitride glasses and Eu2O3 powder using a standard melt‐quenching technique in a radiofrequency furnace. The source Eu trivalent ions primarily changed to Eu2+ during melting, and the ratio of Eu2+ ions increased with an increase in Eu content in the starting mixture. All the prepared glasses exhibited photoluminescence (PL) owing to the 5d–4f transition of Eu2+ ions. The absorption edge and PL wavelength shifted to longer wavelength with an increase in Eu content. Moreover, oxynitride glasses exhibited a longer wavelength than those of oxide glasses. The internal quantum efficiency (IQE) increased with the increase in Eu content until it reached a maximum. X‐ray absorption structure and electron spin resonance spectroscopies were used to determine the local structure of Eu ions, which confirmed that changes in the local structure of Eu ions were responsible for the shift in PL peak and the change in IQE. The development of the Eu‐doped Ca–Al–Si–O–N glasses is highly inspiring for transparent phosphors. [ABSTRACT FROM AUTHOR]

Solvent extraction of Zr(IV) in an undiluted phosphonium based ionic liquid (IL) and its selective separation from Ln(III) and An(III) has been investigated in the present study. Eu(III)/Am(III) were chosen as the representative Ln(III)/An(III). Tri(hexyl)tetradecylphosphonium nitrate ([P66614][NO3]) was chosen as IL phase and the feed phase was nitric acid containing the target metal ions. The extraction process was accomplished at different experimental parameters such as the concentration of initial nitric acid, initial feed metal concentration and equilibration time to explore the extractability of the proposed IL towards Zr(IV). The efficient extraction of Zr(IV) without any external ligand in IL phase and negligible extraction of Eu(III)/Am(III) were distinctly discerned leading to noteworthy separation factors for Zr(IV). The loading experiment revealed a noticeable growth of equilibrium concentrations of Zr(IV) in IL phase while that of Eu(III) was very less irrespective of the initial feed concentration. The association of two IL moieties in the complex formation process has been inferred. Nitrate ion was found to be superior as IL anion in terms of metal loading in comparison to other anions. Thermodynamics of extraction and the stripping of the loaded Zr(IV) from IL phase using a suitable stripping solution have also been investigated. [ABSTRACT FROM AUTHOR]

In this work, five phenanthroline derivatives substituted with different methyl groups have been selected to synthesize β‐diketonate‐based europium complexes to check the influence of the substitutions on the degradation effect of those complexes in poly(methyl methacrylate) (PMMA) films. The photophysical properties of Eu(III) complexes, including absorbance, excitation, and emission have been carefully investigated in solution, solid‐state, and doped in PMMA film. In all these states, the complexes exhibit an impressive red emission at 614 nm with a high photoluminescence quantum yield of up to 85 %. The films have been exposed under outdoor, indoor, and dark storage stability lifetime conditions for 1200 hours. The photoluminescence measurements recorded every 400, 800, and 1200 hours demonstrated that the film containing europium complex with phenanthroline ligand substituted by a high number of methyl groups (Eu(TTA)3L5) showed good photoluminescent stability in indoor and dark conditions, and exhibited better resistance to degradation in outdoor conditions compared to other complexes. This study has proved that phenanthroline ligands could be tuned chemically leading to better stability of those types of complexes in films which can be end‐used for future stable optoelectronic devices such as luminescent solar concentrators. [ABSTRACT FROM AUTHOR]

The incorporation of luminescent lanthanide complexes in inorganic matrices opens appealing possibilities in the rational upstream conception of new luminescent materials with easier recyclability. In this regard, the influence of SBA‐15 mesoporous silica, as a host matrix, on the photophysical properties of europium‐trisdipicolinate cesium salt is investigated. The lanthanide complex can be completely and reversibly adsorbed on the silica, using incipient wetness impregnation (IWI) in WATER, without the need of anchoring groups or covalent bonding on the silica surface. This specific procedure allows the homogeneous dispersion of the lanthanide complex into the host silica matrix. Appropriately assessing the photophysical properties of the targeted luminescent material proved remarkably challenging, demanding utmost caution, particularly due to the strong scattering of the mesoporous matrices. Additionally, while the observations confirm an important increase of luminescence lifetimes of lanthanide complexes upon integration into these mediums, this variation is attributed to the differing refractive indexes and not to specific surface interactions or confinement effect. Indeed, it appeared that previous literature precedents depicted erroneous exhalations of the complexes intrinsic quantum yield due to the repeated use of erroneous refractive index values. In the meantime, the luminance of these materials under UV irradiation improves drastically in comparison to what is obtained with the physical dispersion of micro‐crystals of the lanthanide complex onto silica. It is demonstrated that this improvement is due to a reduced inner filter effect in the adsorbed samples. In this regard, IWI of lanthanide complexes in the mesoporous matrices method could be of interest in the development of recyclable emitting layers, less demanding in terms of emitter quantity. [ABSTRACT FROM AUTHOR]

In this paper, we report on fabricating optical fibers with a controlled process of crystallization core during the drawing process. The research and synthesis of the core material of silica-germanium-antimony oxide glass were discussed. We also investigated the optical and luminescence properties were in relation to concentrating Eu 2 O 3 and P 2 O 5. Based on this investigation, we selected the most promising material for optical fiber core. In the next step, we drew optical fibers using a well-known rod-in-tube method. After drawing, we examine the optical fibers for luminescence shape changes. We observed a promising similarity between optical fibers and heat-treated samples with confirmed nanocrystals. Finally, XRD and TEM measurements confirm EuPO 4 nanocrystals at the core of the optical fiber. Highlighting the successful control of crystallization in the one-step method used to draw optical fibers. [ABSTRACT FROM AUTHOR]

This paper explores the connection between the H3BO3 flux concentration and the co-existence of Eu2+ and Eu3+ dopants within CaMgSi2O6 crystals (diopside). The samples were synthesised using a solid-state synthesis method under varying atmospheric conditions, including oxidative (air), neutral (N2), and reductive (H2/N2 mixture) environments. Additionally, some materials underwent chemical modification by partially substituting Si4+ with Al3+ ions acting as charge compensation defects stabilizing Eu3+ luminescence. Depending on the specific synthesis conditions, the materials predominantly displayed either the orangered luminescence of Eu3+ (under oxidising conditions) or the blue luminescence of Eu2+; however, the comprehensive results confirmed the co-existence of Eu3+/Eu2+ luminescence in both cases. This work shows that varying flux concentrations added during synthesis significantly affect the relative strength of Eu2+ and Eu3+ emissions in a manner dependent on the synthesis atmosphere. The emission of Eu2+ increases with a higher flux concentration in materials synthesised under oxidative and neutral atmospheres independent of the chemical modification. In contrast, for materials obtained under a reductive atmosphere, the changes in the Eu3+ emission intensity depended on the presence or absence of Al3+ ions namely the increase of flux increased the Eu3+ intensity in the case of unmodified materials and decreased in the Al-modified ones. All observed effects were qualitatively explained considering the double role of the flux in the studied system, which besides facilitating the diffusion of chemical species during synthesis acts as a charge compensating agent by creating B'Si centres stabilizing Eu3+ emission. [ABSTRACT FROM AUTHOR]

Ascorbic acid (AA) is a biomarker of some nervous system diseases, whose detection is of significance in many fields. The hydrothermal reaction of naphthalene‐2,6‐dicarboxylic acid (H2NDBC) with Eu3+ produced a europium MOF, Eu‐NDBC. Eu‐NDBC emits the combined emissions from the intraligand charge transfer (ILCT) of NDBC2− ligand and 5D0→7Fj (j=1–4) transfers of Eu(III). The factors of MOF dosage, pH and fluorescence response time are optimized as 0.6 mg, 7.35, and 5 min respectively. The sensitivity test shows a linear fitting equation of I0/I=0.00239 ⋅ CAA+1.03774 (CAA=AA concentration), with its limit of detection calculated as 4.53 μM in a wide linear range of 0–900 μM. The linear fitting of Stern‐Volmer equation gives KSV=2.46×103 M−1 and Kq=4.96×106 M−1 S−1, suggesting Eu‐NDBC sensing AA is a dynamic fluorescence quenching process. Nine control amino acids can't affect Eu‐NDBC sensing AA and the emission intensity stay stable in five fluorescence quenching‐recovery cycles. The returned CAA closed to the set CAA and the recoveries around 100 % support the accurate AA detection by Eu‐NDBC in human serum. Totally, Eu‐NDBC can be regarded as a quantitative turn‐off fluorescence sensor to AA with high sensitivity and selectivity, rapid response and durability. [ABSTRACT FROM AUTHOR]

The measurement of quantum yield (QY) is an important process for a phosphor. This is often accomplished by the comparison of the low‐temperature lifetime with the room temperature (RT) lifetime. It is shown that this procedure provides a considerable underestimation of QY in certain cases. Additionally, the use of the europium ion as an indicator of changes in site symmetry with temperature has severe limitations. This work reveals that a decrease in measured lifetime with increasing temperature of a system cannot always be associated with a descent in site symmetry and may be due to increasing radiative rate. [ABSTRACT FROM AUTHOR]

Coordination compounds of europium(III), terbium(III), samarium(III) acetates with 1,10-phenanthroline (phen) and 5-phenyltetrazole (HL) are synthesized. By the single crystal X-ray diffraction (XRD) analysis of the samarium(III) complex the compound is found to be binuclear with formula [Sm2(phen)2(CH3COO)6]·2HL. By the powder XRD analysis of polycrystalline samples all obtained complexes are found to be isostructural. A change in the synthesis procedure of the europium(III) acetate–phen–HL system leads to the formation of [Eu(phen)2(H2O)3(CH3COO)]L2·6H2O single crystals. The photoluminescent properties of the polycrystalline compounds are studied: emission and excitation spectra are recorded and the quantum yield is calculated. The HL quantum yield is 33% while it is 36% and 22% for the obtained complexes of europium(III) and terbium(III) respectively. The excited state lifetime is also determined for lanthanide(III) complexes: 1.6 ms for europium(III) and 0.6 ms for terbium(III). [ABSTRACT FROM AUTHOR]

Lanthanide ions have ideal chemical properties for catalysis, such as hard Lewis acidity, fast ligand‐exchange kinetics, high coordination‐number preferences and low geometric requirements for coordination. As a result, many small‐molecule lanthanide catalysts have been described in the literature. Yet, despite the ability of enzymes to catalyse highly stereoselective reactions under gentle conditions, very few lanthanoenzymes have been investigated. In this work, the mononuclear binding of europium(III) and gadolinium(III) to the active site of a mutant of the model enzyme phosphotriesterase are described using X‐ray crystallography at 1.78 and 1.61 Å resolution, respectively. It is also shown that despite coordinating a single non‐natural metal cation, the PTE‐R18 mutant is still able to maintain esterase activity. [ABSTRACT FROM AUTHOR]

The effect of the addition of Nb2O5 (up to 5 mol%) on the structure and luminescent properties of ZnO-B2O3 glass doped with 0.5 mol% (1.32 × 1022) Eu2O3 was investigated by applying infrared (IR), Raman and photoluminescence (PL) spectroscopy. Through differential thermal analysis and density measurements, various physical properties such as molar volume, oxygen packing density and glass transition temperature were determined. IR and Raman spectra revealed that niobium ions enter into the base zinc borate glass structure as NbO4 tetrahedra and NbO6 octahedra. A strong red emission from the 5D0 level of Eu3+ ions was registered under near UV (392 nm) excitation using the 7F0 → 5L6 transition of Eu3+. The integrated fluorescence intensity ratio R (5D0 → 7F2/5D0 → 7F1) was calculated to estimate the degree of asymmetry around the active ion, suggesting a location of Eu3+ in non-centrosymmetric sites. The higher Eu3+ luminescence emission observed in zinc borate glasses containing 1–5 mol% Nb2O5 compared to the Nb2O5-free zinc borate glass evidences that Nb2O5 is an appropriate component for modifying the host glass structure and improving the emission intensity. [ABSTRACT FROM AUTHOR]

BACKGROUND: Rice, a pivotal global food staple, annually accumulates vast amounts of rice husks, resulting in substantial environmental impact. Exploiting the high silica content in rice husk, our research aimed to recycle this agricultural byproduct to synthesize mesoporous silica nanoparticles (rMSNs). These nanoparticles were further modified to evaluate their potential as effective carriers for cancer drug delivery. RESULTS: rMSNs showed high biocompatibility, large surface area and porous structure as MSNs, making them excellent drug carriers. Further modifications were applied to rMSNs, such as the incorporation of the lanthanides europium and gadolinium into rMSNs, making them fluorescent and magnetic for detection and tracking using confocal fluorescence microscopy and magnetic resonance imaging. Additionally, folic acid and aptamer AS1411 were conjugated with rMSNs to enhance the targeting of cancer cells. HeLa cells exhibited higher uptake of camptothecin (CPT)‐loaded rMSNs compared to normal fibroblast cells (L929). The linkage of disulfide bonds to rMSNs also allowed CPT to be carried by rMSNs and released intracellularly in the presence of the abundant reducing agent glutathione. The validation of rMSNs in vitro and in vivo proved their practical feasibility. CONCLUSION: Our findings indicate that low‐cost rMSNs, derived from recycled agricultural waste, can replace highly valuable MSNs. Functionalized rMSNs exhibit promising capabilities in transporting clinical drugs to specific aberrant tissues and offering dual‐targeting and dual‐imaging functionalities for enhanced cancer therapy. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The stability constants of the complexes of europium(III) and terbium(III) ions with terephthalic acid anions were determined by potentiometric titration over a wide pH range. The luminescent properties of these complexes were studied. It was shown that the complexes are most stable in slightly acidic solutions. Analysis of the photoluminescence emission spectra confirmed the adequacy of the proposed model of complexation. [ABSTRACT FROM AUTHOR]

A systematic study of the effectiveness of various chromophores of the 5-aryl-2,2ʹ-bipyridine series was carried out in terms of sensitization of lanthanide(III) cations. For this purpose, the corresponding DTTA-appended 5-aryl-2,2′-bipyridines were synthesized in good yields by using the "1,2,4-triazine" methodology, and their europium(III) and terbium(III) complexes were prepared. The photophysical properties were studied for all the obtained chelates, and the influence of the nature of the aryl substituent of the bipyridine core was estimated. The positive influence of the halogen atoms as well as a methyl group on the efficiency of the lanthanide(III) cation sensibilization was demonstrated. The influence of the nature of the residue of the polyaminocarboxylic acid fragment in the ligand on the luminescent characteristics of its lanthanide complexes was also studied. [ABSTRACT FROM AUTHOR]

Cerium oxide nanoparticles (CeONPs) exhibiting antioxidant properties are investigated as potential tools for neurodegenerative diseases. Here, we synthesized polyacrylic acid conjugated cerium oxide (CeO) nanoparticles, and further to enhance their neuroprotective effect, Eu3+ was substituted at different concentrations (5, 10, 15 and 20 mol%) to the CeO, which can also impart fluorescence to the system. CeONPs and Eu-CeONPs in the size range of 15–30 nm were stable at room temperature. The X-ray Photoelectron Spectroscopy (XPS) analysis revealed the chemical state of Eu and Ce components, and we could conclude that all Eu3+ detected on the surface is well integrated into the cerium oxide lattice. The emission spectrum of Eu-CeO arising from the 7F0 → 5D1 MD and 7F0 → 5D2 transitions indicated the Eu3+ ion acting as a luminescence center. The fluorescence of Eu-CeONPs was visualized by depositing them at the surface of positively charged latex particles. The developed nanoparticles were safe for human neuronal-like cells. Compared with CeONPs, Eu-CeONPs at all concentrations exhibited enhanced neuroprotection against 6-OHDA, while the protection trend of Eu-CeO was similar to that of CeO against H2O2 in SH-SY5Y cells. Hence, the developed Eu-CeONPs could be further investigated as a potential theranostic probe. [ABSTRACT FROM AUTHOR]

Boromullite is a mineral containing oxides of aluminium, boron and silicon with the chemical formula Al9BSi2O19. It has been known for more than two decades, yet it has not been explored for luminescence. We succeeded in obtaining the synthetic Boromullite by the combustion method. Activators Europium and Cerium could be incorporated during the preparation. Typical features of Ce3+, Eu3+ and Eu2+ could be observed. To the best of our knowledge, these are the first observations of luminescence in Boromullite. These studies on synthetic material can help in studying the natural minerals, e.g. in identifying using fluoroscopy. [ABSTRACT FROM AUTHOR]

Distributions of Eu2+ and Eu3+ do affect the optical properties. However, the substitution of the activator ions hardly perturbed the crystal structure of the host lattice. Without the differences in crystal structure, it is not trivial to develop an effective descriptor to investigate stoichiometry-dependent mechanism to explore the effects of Eu species on valence states. In this study, through x-ray nanodiffraction, x-ray fluorescence, x-ray absorption near edge structure, and x-ray excited optical luminescence, we mapped the valence state distributions of Eu species to calculate the local mixing enthalpy and entropy. The calculated thermodynamics parameters show good agreement with the optical properties. We found that Eu2+ of Eu-doped BaAl2O4 predominantly existed in a divalent state, which results in segregation phenomena of local Eu2+ and Eu3+ ions. [ABSTRACT FROM AUTHOR]

Functional materials exhibiting polymorphism serve as excellent candidates for various optical applications since the properties can be tuned to the desired target/application by modifying the structural features. Herein, we explored the synthesis of Eu3+ doped gadolinium oxyfluoride systems via a green microwave-assisted hydrothermal method, and phase controllability was established by varying the O2− to F- ratio. The phase evolution and crystal structure of the Eu3+ doped oxyfluoride analogs were examined using Rietveld refinement studies, and the results were consistent with the site symmetries unveiled by the photoluminescence spectra of Eu3+. The low phonon energy of all the phosphors, calculated from the Raman spectra, suggested the possibility of these groups of materials as excellent host matrices for optical applications. Further, a drastic variation in the morphology of studied oxyfluorides at different phases is evidenced by the electron microscopic analysis. The highly asymmetric rhombohedral sites enhanced the color purity, lifetime, and quantum yield of the red phosphor, making it an excellent red component for the fabrication of UV-excitable red as well as white light-emitting diodes for lighting and display device functionalities. [ABSTRACT FROM AUTHOR]

The thermosensing and thermochromic behavior of one of our recently reported terpyridyl-imidazole based ternary europium tris-(β-diketonate) complexes of the composition [Eu(tta)3(tpy-HImzphen)] (tta = 2-thenoyltrifluoroacetone and tpy-HImzphen = 2-(4-[2,2′:6′,2′′] terpyridin-4′-yl-phenyl)-1H-phenanthro[9,10-d]imidazole) has been thoroughly investigated in this work. The said Eu(III) complex exhibits magnificent thermosensing as well as thermochromic properties and can be recommended as an excellent temperature sensor in a wide temperature domain of 273–343 K in terms of both emission intensity ratio (Sm = 5.78% K−1 at Tm = 343 K, δT = 0.012 K) and lifetime values (Sm = 3.36% K−1 at Tm = 333 K, δT = 0.009 K) or even in terms of its emitting color (red at 268 K, violet at 303 K, and blue at 343 K). Additionally, it displays remarkable solvent-induced luminescence behavior by displaying various emitting colors instead of its sole characteristic red emission upon varying the nature of the solvent. Finally, amalgamating these two features, we are able to attain white light emission (Commission Internationale de l'Eclairage coordinates: x = 0.34, y = 0.38) at 283 K from a single component. A plausible energy transfer mechanism has also been proposed in light of the existence of the ligand-to-metal charge transfer (LMCT) state as the quencher. [ABSTRACT FROM AUTHOR]

In afterglow phosphors, luminescence appears and can be observed with the naked eye for minutes to hours or more, even after photoexcitation ceases. Red afterglow and photostimulated luminescence (PSL) at 650 nm are studied in CaS:Eu2+, Mn2+ phosphors. Infrared light at 980 nm from a laser diode induces the red PSL for 990 s. Two types of trap states are found to be present in the phosphors by using thermoluminescence (TL). Deep trap states are reflected in a TL peak in the temperature region of 520 K, and are related to PSL. Shallow trap states reflected in the other TL peak at 250 K are related to afterglow. The intensity dependence of photoexcitation on PSL shows that carriers are more easily accumulated in the deep trap states than shallow trap states. Experiments of electron paramagnetic resonance are conducted to discuss the possible origins of PSL and the afterglow. [ABSTRACT FROM AUTHOR]

Europium (Eu3+) doped phosphors typically exhibit orange or red emission and are used in lighting and display applications, originating from the 5D0→7F1 and 5D0→7F2 transitions of Eu3+. However, BaLaGaO4: xEu3+ deep‐red phosphor, when excited by near‐ultraviolet light, is mainly 5D0→7F4 transition (703 nm). Meantime, the BaLaGaO4: 0.30Eu3+ exhibits a high I423K/I298K value of 71% and a high quantum yield of 82.54%. Furthermore, the prepared samples are mixed with commercial blue and green phosphors in a certain proportion to make white light‐emitting diodes (WLEDs). The color coordinate of the fabricated WLEDs is (0.3208, 0.3436), with a color rendering index of 91.9 and an R9 value of 73. Based on the unique spectral characteristics of this compound, a prototype device of a deep‐red LED with phosphor conversion is developed, which exhibits color coordinates (0.6294, 0.3581) and a color purity of 96.4%. The conducted germination experiments with plant seeds have provided compelling evidence regarding the considerable positive effects of the deep‐red LEDs on plant growth. These findings further emphasize the highly promising potential application of BaLaGaO4: Eu3+ deep‐red phosphor in WLEDs and plant growth lighting. [ABSTRACT FROM AUTHOR]

Understanding the factors that shape the circularly polarised luminescence (CPL) emission profiles of europium(III)‐based CPL emitters to have specific sign properties, e. g. monosignate individual CPL transitions, is key to design novel complexes for applications ranging from advanced security inks to bio‐probes for live cell imaging. In order to correlate structure and spectral characteristics, a photophysical and kinetic investigation has been conducted on a series of coordinatively saturated nine‐coordinate europium(III) systems based on 1,4,7‐triazacyclononane. We highlight that lanthanide emission is sensitive to changes in the ligand field by showing the linear dependence of total emission intensity ratios as a function of solvent polarity, for europium(III) complexes displaying an internal charge transfer (ICT) excited state. This sensitivity increases by a factor of 20 when studying changes in CPL spectra, rendering these complexes accurate probes of local polarity. Solvent polarity, solvent‐specific effects, and the nature of the chromophores' coordinating donor atoms strongly influence the kinetic stability of europium(III) complexes with respect to enantiomer interconversion. Notably, we show that the choice of donor groups to coordinating to europium(III) and the nature and polarity of the solvent affects the rate of racemisation, leading to systems with very long half‐lives at room temperature in non‐polar media. [ABSTRACT FROM AUTHOR]

A series of novel lanthanide β‐diketonate coordination compounds containing the ancillary ligand bis(diphenylphosphino) oxide (dppeO2) have been synthesized, characterized, and studied spectroscopically. The compounds of formulas Ln(β‐dik)3(dppeO2), where Ln: Eu and Gd and β‐dik ligands as tta (Ln‐1), btf (Ln‐2), bzac (Ln‐5) and tfac (Ln‐4), and Ln2(β‐dik)6(dppeO2) with ligand dbm (Ln‐3) and fod (Ln‐6). Their photophysical properties were investigated from the Judd‐Ofelt intensity parameters (Ωλ ${{\Omega }_{\lambda }}$), radiative (Arad ${{A}_{rad}}$) and non‐radiative (Anrad ${{A}_{nrad}}$) rates, intrinsic (QEuEu ${{Q}_{Eu}^{Eu}}$) and overall (QEuL ${{Q}_{Eu}^{L}}$) quantum yields, and CIE (x,y) color coordinates. The Eu‐5 and Eu‐6 compounds have the first excited triplet states T1 (around 18802 and 18976 cm−1, respectively) almost resonant with the Eu3+ 5D0 emission level, whereas the complexes Eu‐1, Eu‐2, Eu‐3, and Eu‐4 exhibited higher T1 energies. The Arad ${{A}_{rad}}$ values were predominantly driven by the intensity parameter Ω2 ${{\Omega }_{2}}$ , suggesting more pronounced angular changes in the first coordination sphere of the Eu3+ ion. The Anrad ${{A}_{nrad}}$ values also exhibited significant changes with the β‐diketonate ligands. Eu‐1 showed the highest value of QEuL ${{Q}_{Eu}^{L}}$ (60 %), indicating a more efficient intramolecular energy transfer process. On the other hand, Eu‐5 and Eu‐6 compounds showed QEuL ${{Q}_{Eu}^{L}}$ values equal to 18.7 % and 16.5 %, respectively, which indicates the presence of luminescence quencher channels. [ABSTRACT FROM AUTHOR]

We report a synthesis of a series of molecular compounds and coordination polymers of Zn2+, Mn2+ Cd2+, Eu3+, and Tb3+ with 4-allyl-2,3,5,6-tetrafluorobenzoic acid (4-Afb) anions and 1,10-phenanthroline with compositions [Zn(H2O)(phen)(4-Afb)2] (1), [Mn(H2O)(phen)(4-Afb)2]n·nH2O (2), [Cd(H2O)(phen)(4-Afb)2]n (3), [Cd(phen)(4-Afb)2]n (4), [Ln2(phen)2(4-Afb)6] (Ln = Eu 5Eu; Tb 5Tb). It is shown that the obtained cadmium coordination polymers have various compositions and structures, depending on crystallization conditions. The prepared compounds are characterized by single-crystal XRD, powder XRD, IR spectroscopy, and CHN analysis. Noncovalent interactions are analyzed using the Hirshfeld surface analysis. It is determined that the crystal packings is mainly stabilized by π⋯π, C–H⋯F, and C–F⋯π interactions. The photoluminescent properties of the 5Eu and 5Tb complexes are studied. It is shown that the structure-forming effects of non-covalent "arene–perfluoroarene" interactions can be possibly used for preorganizing reactive functional groups in the crystal. [ABSTRACT FROM AUTHOR]

The structural characterization of 3,4-dichloroisothiazole-5-carboxylic acid is performed for the first time along with the preparation of the first coordination compound based on it - a mixed-ligand europium(III) complex with 3,4-dichloroisothiazole-5-carboxylic acid and 1,10-phenanthroline. The coordination compound is characterized by the elemental analysis, single crystal and powder X-ray diffraction (XRD), and IR spectroscopy. According to the single crystal XRD data, the obtained complex is a binuclear compound with the formula [Eu2L6(phen)2(H2O)2]·6H2O. Its structure corresponds to the Chinese lantern type. The isothiazole derivative exhibits both monodentate and bidentate-bridging coordinations binding europium ions. The photoluminescent properties of a polycrystalline sample of the complex are studied: the luminescence quantum yield is 23%, the excited state lifetime is 0.8 ms. [ABSTRACT FROM AUTHOR]

C39H30N9O6Eu, monoclinic, C2/c (no. 15), a = 31.579(6) Å, b = 10.0462(19) Å, c = 27.325(5) Å, β = 121.891(2)°, V = 7360(2) Å3, Z = 8, Rgt(F) = 0.0295, wRref(F2) = 0.0835, T = 298 K [1–3]. [ABSTRACT FROM AUTHOR]

A dinuclear complex [(H2O)Zn(LH)Eu(NO3)3] containing a hexadentate Schiff-base {N2O4}-donor ligand LH2− was prepared and characterized by X-ray structural analysis and IR, electronic and fluorescence spectroscopy. DC magnetic data show that upon heating the diamagnetic complex with the ground state Eu(III)–7F0 and Zn(II)–1S switches to paramagnetic species due to the population of 7FJ (J = 1 to 6) magnetic multiplets. The magnetic susceptibility increases from zero, passes through a maximum, and then decreases upon heating. This behaviour can be explained using a spin–orbit Hamiltonian with an axial distortion term. There is an alternative interpretation of the susceptibility data based on a two-level model similar to that used in the spin crossover theory. [ABSTRACT FROM AUTHOR]

In this work, three series of micro-sized heterometallic europium-containing terephthalate MOFs, (Eu1-xLnx)2bdc3·nH2O (Ln = La, Gd, Lu), are synthesized via an ultrasound-assisted method in an aqueous medium. La3+ and Gd3+-doped terephthalates are isostructural to Eu2bdc3·4H2O. Lu3+-doped compounds are isostructural to Eu2bdc3·4H2O with Lu contents lower than 95 at.%. The compounds that are isostructural to Lu2bdc3·2.5H2O are formed at higher Lu3+ concentrations for the (Eu1-xLux)2bdc3·nH2O series. All materials consist of micrometer-sized particles. The particle shape is determined by the crystalline phase. All the synthesized samples demonstrate an "antenna" effect: a bright-red emission corresponding to the 5D0-7FJ transitions of Eu3+ ions is observed upon 310 nm excitation into the singlet electronic excited state of terephthalate ions. The fine structure of the emission spectra is determined by the crystalline phase due to the different local symmetries of the Eu3+ ions in the different kinds of crystalline structures. The photoluminescence quantum yield and 5D0 excited state lifetime of Eu3+ are equal to 11 ± 2% and 0.44 ± 0.01 ms, respectively, for the Ln2bdc3·4H2O structures. For the (Eu1-xLux)2bdc3·2.5H2O compounds, significant increases in the photoluminescence quantum yield and 5D0 excited state lifetime of Eu3+ are observed, reaching 23% and 1.62 ms, respectively. [ABSTRACT FROM AUTHOR]

A reaction in anhydrous toluene between the formally unsaturated fragment [Ln(hfac)3] (Ln3+ = Eu3+, Gd3+ and Er3+; Hhfac = hexafluoroacetylacetone) and [Al(qNO)3] (HqNO = 8-hydroxyquinoline N-oxide), here prepared for the first time from [Al(OtBu)3] and HqNO, affords the dinuclear heterometallic compounds [Ln(hfac)3Al(qNO)3] (Ln3+ = Eu3+, Gd3+ and Er3+) in high yields. The molecular structures of these new compounds revealed a dinuclear species with three phenolic oxygen atoms bridging the two metal atoms. While the europium and gadolinium complexes show the coordination number (CN) 9 for the lanthanide centre, in the complex featuring the smaller erbium ion, only two oxygens bridge the two metal atoms for a resulting CN of 8. The reaction of [Eu(hfac)3] with [Alq3] (Hq = 8-hydroxyquinoline) in the same conditions yields a heterometallic product of composition [Eu(hfac)3Alq3]. A recrystallization attempt from hot heptane in air produced single crystals of two different morphologies and compositions: [Eu2(hfac)6Al2q4(OH)2] and [Eu2(hfac)6(µ-Hq)2]. The latter compound can be directly prepared from [Eu(hfac)3] and Hq at room temperature. Quantum mechanical calculations confirm (i) the higher stability of [Eu(hfac)3Al(qNO)3] vs. the corresponding [Eu(hfac)3Alq3] and (ii) the preference of the Er complexes for the CN 8, justifying the different behaviour in terms of the Lewis acidity of the metal centre. [ABSTRACT FROM AUTHOR]

Raman optical activity (ROA) is commonly measured with green light (532 nm) excitation. At this wavelength, however, Raman scattering of europium complexes is masked by circularly polarized luminescence (CPL). This can be avoided using near‐infrared (near‐IR, 785 nm) laser excitation, as demonstrated here by Raman and ROA spectra of three chiral europium complexes derived from camphor. Since luminescence is strongly suppressed, many vibrational bands can be detected. They carry a wealth of structural information about the ligand and the metal core, and can be interpreted based on density functional theory (DFT) simulations of the spectra. For example, jointly with ROA experimental data, the simulations make it possible to determine absolute configuration of chiral lanthanide compounds in solution. [ABSTRACT FROM AUTHOR]

The development of multimodal nano- and micro-structures has become an increasingly popular area of research in recent years. In particular, the combination of two or more desirable properties within a single structure opens multiple opportunities from biomedicine, sensing, and catalysis, to a variety of optical applications. Here, for the first time, we report the synthesis and characterization of multimodal chiroptically active CaCO3 nanocomposites. These composites have been prepared by a modified microemulsion method in the presence of an amino acid (cysteine). Following this, additional modalities have been introduced by loading the composites with luminescent nanoparticles or doping with Eu3+ ions. The luminescent composites have been produced by the incorporation of CuInZnS/ZnS or CdSe@ZnS/ZnS core/shell quantum dots, or via doping with trivalent europium. In this manner, we have produced chiroptically active composites with orange, green, and red luminescence. Overall, this work demonstrates the unique advantage and potential of our approach and new class of chiroptically active CaCO3 nanocomposites, which display tunable functionality to specific requirements via the incorporation of desired ions, nanoparticles, and chirality of the structure. [ABSTRACT FROM AUTHOR]

This study offers a new simplified approach of diglycolamides synthesis, extraction agents used in separation procedures in various fields of nuclear chemistry such as waste management, spent nuclear fuel reprocessing, radioecology or radiopharmacy. The synthesis is assisted by coupling agent, propylphosphonic anhydride, commercially known as T3P®. Using this agent allows to perform the synthesis in a single step and to synthesize also novel types of diglycolamides that have not been described, yet. Thus, this approach helps to widen the spectrum of prepared diglycolamides and possible use of these extraction agents. Prepared diglycolamides insoluble in water were immobilized on polymer matrix and used as solid extractants in pilot batch experiments with Eu(III) ions in order to confirm the quality of known diglycolamides and asses the quality of novel ones. [ABSTRACT FROM AUTHOR]

The solid solutions Eu2Al15(Pt1−xTx)6 with T = Pd, Ir, Au and x = 1/6 were prepared by arc-melting the stoichiometric mixture of the elements, and subsequent annealing. For x = 1/6, all three solid solutions adopt the same structure type as Eu2Al15Pt6 according to powder X-ray diffraction data. Since the platinide Eu2Al15Pt6 exhibits a (3 + 1)D modulated structure (approximant in space group P121/m1), only the averaged hexagonal unit cell (P63/mmc, Sc0.6Fe2Si4.9 type) was refined by the Rietveld method. Scanning electron microscopy in combination with energy-dispersive X-ray spectroscopy (SEM/EDX) showed that the degree of substitution is in line with the weighed amounts. For values of x > 1/6, no phase-pure samples could be obtained. The results of the magnetic susceptibility measurements indicate that the isoelectronic substitution of Pd for Pt lowers the temperature of the first-order valence phase transition from Ttrans = 45 K in Eu2Al15Pt6 to Ttrans = 42 K in Eu2Al15(Pt5/6Pd1/6)6. For Eu2Al15(Pt5/6Ir1/6)6 and Eu2Al15(Pt5/6Au1/6)6 a change in the electronic situation occurs since the Ir substituted compound exhibits one electron less compared to the pristine Pt compound, while Eu2Al15(Pt5/6Au1/6)6 has one additional electron. As a consequence, Eu2Al15(Pt5/6Ir1/6)6 shows a higher valence phase transition temperature of Ttrans = 52 K while for Eu2Al15(Pt5/6Au1/6)6 no such transition is obvious. [ABSTRACT FROM AUTHOR]