Lanthanide Ions Research Articles

Upconverting Ultra-Thin Bi2O2CO3 Nanosheets for Synergistic Photodynamic Therapy and Radiotherapy.

Synergistic therapy has become the major therapeutic method for malignant tumors in clinical. Photodynamic therapy (PDT) and radiotherapy (RT) always combine together because of their identical anti-tumor mechanisms, that is reactive oxygen species are generated by the use of radiosensitizers after irradiation by X-ray to efficiently kill cancer cells, PDT also follows similar mechanism. Full exposure of energy-absorbing species in nanomaterials to X-ray or near-infrared light irradiation makes the energy interchange between nanomaterials and surrounding H2O or dissolved oxygen easier, however, it remains challenging. Herein, an ultrathin two-dimensional (2D) nanosheet (NS) is developed, Bi2O2CO3, doped with lanthanide ions to give out upconversion luminescence, where the high Z elements Bi, Yb, and Er promote the radio-sensitizing effect. To the surprise, lanthanide activator ions gave out completely different luminescence properties compared with traditional upconversion nanoparticles. Less dopant of Er ions in nanosheets lattice resulted in brighter red emission, which provides more efficient PDT. Under RT/PDT combined treatment, NS shows a good tumor growth-inhibiting effect. In addition, synergistic therapy requires lower radiation dose than conventional radiotherapy and lower light power than single photodynamic therapy, thus greatly reducing radiation damage caused by RT and thermal damage caused by PDT.

Selective Liquid-Liquid Extraction of Thorium(IV) from Rare-Earth Element Mixtures.

One of the major challenges in processing rare-earth element (REE) materials arises from the large amounts of radioactive thorium (Th) that are often found within REE minerals, encouraging enhanced metal separation procedures. We report here a study aimed at developing improved systems for REE processing with the goal of efficient extraction of Th(IV) from acidic solution. A tripodal ligand, TRPN-CMPO-Ph, was prepared that utilizes carbamoylmethylphosphine oxide (CMPO) chelators tethered to a tris(3-aminopropyl)amine (TRPN) capping scaffold. The ligand and its metal complexes were characterized by using elemental analysis, NMR, Fourier transform infrared spectroscopy, mass spectrometry, and luminescence spectroscopy. Using a liquid-liquid metal extraction protocol, TRPN-CMPO-Ph selectively extracts Th(IV) at an efficiency of 79% from a mixture of Th(IV), UO22+, and all rare-earth metal cations (except promethium) dissolved in nitric acid into an organic solvent. Th(IV) extraction selectivity is maintained upon extraction from a mixture that approximates a typical monazite leach solution containing several relevant lanthanide ions, including two ions at higher concentration relative to Th(IV). Comparative studies with a tris(2-aminoethyl)amine (TREN)-capped derivative are presented and support the need for a larger TRPN capping scaffold in achieving Th(IV) extraction selectivity.

Contrasting role of Ca2+ on the Gd2TiO5: Eu3+ light emission under charge transfer and f-f band excitation: Interplay of oxygen vacancies and structural distortion

The possibility of generating new lanthanide ion doped inorganic material that could work efficiently towards solid-state lighting was explored. The material studied in this work is Gd2TiO5 doped with Eu3+ which displays the lowest lattice strain, high solubility, and lacks both charge-compensating defects and structural deformation. In this study, the impacts of exchanging Gd with up to 10 mol% of Ca, an optically inactive ion, on the luminescence characteristics are investigated. Only small variations in the positron lifetimes suggest the Ca2+ doping only enhanced oxygen vacancies in the system.. Time resolved photoluminescence suggested that the emission intensity increases with Ca2+content when excited with 395 nm (f-f band) while it reduced when excited with 270 nm (charge transfer). The host to dopant energy transfer is attributed to the charge transfer from O2− to Eu3+ and the creation of oxygen vacancies due to Ca2+ doping reduced the charge transfer intensity. The intensity with excitation at 395 nm is almost doubled upon 10 % Ca doping and is attributed to enhanced distortions around the dopant favouring the direct excitation of Eu3+. The creation of oxygen vacancies via Ca substitution and the resultant distortions around Eu3+ ion have resulted in opposite variations in the emission intensity under excitation using charge transfer band and direct excitation. The study offers the possibility of exploring more methods of creating vacancies and distortions around Eu3+ to induce the spectral shifts.

High-efficiency dysprosium-ion extraction enabled by a biomimetic nanofluidic channel

Biological ion channels exhibit high selectivity and permeability of ions because of their asymmetrical pore structures and surface chemistries. Here, we demonstrate a biomimetic nanofluidic channel (BNC) with an asymmetrical structure and glycyl-L-proline (GLP) -functionalization for ultrafast, selective, and unidirectional Dy3+ extraction over other lanthanide (Ln3+) ions with very similar electronic configurations. The selective extraction mainly depends on the amplified chemical affinity differences between the Ln3+ ions and GLPs in nanoconfinement. In particular, the conductivities of Ln3+ ions across the BNC even reach up to two orders of magnitude higher than in a bulk solution, and a high Dy3+/Nd3+ selectivity of approximately 60 could be achieved. The designed BNC can effectively extract Dy3+ ions with ultralow concentrations and thereby purify Nd3+ ions to an ultimate content of 99.8 wt.%, which contribute to the recycling of rare earth resources and environmental protection. Theoretical simulations reveal that the BNC preferentially binds to Dy3+ ion due to its highest affinity among Ln3+ ions in nanoconfinement, which attributes to the coupling of ion radius and coordination matching. These findings suggest that BNC-based ion selectivity system provides alternative routes to achieving highly efficient lanthanide separation.

Chiral Star-Shaped [CoIII3LnIII] Clusters with Enantiopure Schiff Bases: Synthesis, Structure, and Magnetism.

Two enantiomeric pairs of new 3d-4f heterometallic clusters have been synthesized from two enantiomer Schiff base derivatives: (R/S)-2-[(2-hydroxy-1-phenylethylimino)methyl] phenol (R-/S-H2L). The formulae of the series clusters are Co3Ln(R-L)6 (Ln = Dy (1R), Gd (2R)), Co3Ln (S-L)6 (Ln = Dy (1S), Gd (2S)), whose crystal structures and magnetic properties have been characterized. Structural analysis indicated that the above clusters crystallize in the chiral P213 group space. The central lanthanide ion has a coordination geometry of D3 surrounded by three [CoIII(L)2]- anions using six aliphatic oxygen atoms of L2- featuring a star-shaped [CoIII3LnIII] configuration. Magnetic measurements showed the presence of slow magnetic relaxation with an effective energy barrier of 22.33 K in the DyIII derivatives under a zero-dc field. Furthermore, the circular dichroism (CD) spectra of 1R and 1S confirmed their enantiomeric nature.

Rare Earth Element Binding and Recovery by a Beta Roll-Forming RTX Domain.

The Block V of the RTX domain of the adenylate cyclase protein from Bordetella pertussis is disordered, and upon binding eight calcium ions, it folds into a beta roll domain with a C-terminal capping group. Due to their similar ionic radii and coordination geometries, trivalent lanthanide ions have been used to probe and identify calcium-binding sites in many proteins. Here, we report using a FRET-based assay that the RTX domain can bind rare earth elements (REEs) with higher affinities than calcium. The apparent disassociation constants for lanthanide ions ranged from 20 to 75 μM, which are an order of magnitude higher than the affinity for calcium, with a higher selectivity toward heavy REEs over light REEs. Most proteins release bound ions at mildly acidic conditions (pH 5-6), and the high affinity REE-binding lanmodulin protein can bind 3-4 REE ions at pH as low as ∼2.5. Circular dichroism (CD) spectra of the RTX domain demonstrate pH-induced folding of the beta roll domain in the absence of ions, indicating that protonation of key amino acids enables structure formation in low pH solutions. The beta roll domain coordinates up to four ions in extreme pH conditions (pH < 1), as determined by equilibrium ultrafiltration experiments. Finally, to demonstrate a potential application of the RTX domain, REE ions (Nd3+ and Dy3+) were recovered from other non-REEs (Fe2+ and Co2+) in a NdFeB magnet simulant solution (at pH 6).

Single-bubble sonoluminescence of itterbium(II or III) and thulium(II or III) chloride nanoparticles colloidal suspensions in dodecane

Colloidal suspensions of nanoparticles of di- and trivalent ytterbium and thulium chloride crystals in dodecane were prepared by ultrasonic dispersion. The average nanoparticle size in the suspensions was 20–35 nm. During single-bubble sonolysis with the bubble moving at the standing wave antinode, identical bands with a maximum at 550 nm appeared in the sonoluminescence spectra with spectral resolution Δλ = 15 nm for suspensions of both Yb(II) and Yb(III) salts. Bands with a maximum at 600 nm were found for suspensions of Tm(II) and Tm(III) salts. These sonoluminescence bands coincide with the photoluminescence bands of Yb(II) (550 nm) or Tm(II) (600 nm) salts, respectively. For suspensions of divalent lanthanide salts, these sonoluminescence bands appear when nanoparticles get into a moving bubble, because of collisional excitation of Yb(II) or Tm(II) in the bubble plasma, which periodically appears during acoustic oscillations: [Ln(II)]suspension → [Ln(II)]bubble → [Ln(II)]plasma → [Ln(II)*]plasma → Ln(II) + hνLn(II). The presence of analogous bands for suspensions of trivalent lanthanide salts is caused, in particular, by also their reduction in the plasma after they get into a bubble: [Ln(III)]suspension → [Ln(III)]bubble → [Ln(III)]plasma → [Ln(II), Ln(II)*]plasma → [Ln(II)*]plasma → Ln(II) + hνLn(II). The reduction of lanthanide ions in the bubble plasma is not limited to the reaction Ln(III) → Ln(II), Ln(II)*, but can proceed further giving singly charged lanthanide cations and lanthanide atoms: Ln(II) → Ln(I), Ln(I)* → Ln(0), Ln(0)*. The single-bubble sonoluminescence spectra with Δλ = 1.5 nm for a suspension of Yb(III) salt showed characteristic lines of Yb(I) and Yb(0). These characteristic lines and bands for ytterbium and thulium atoms and ions are suitable for sonoluminescent spectroscopic analysis, that is, identification and quantification of ions in solutions and suspensions and determination of electronic temperature in bubble plasma.

Fine-tuning of redox-ability, optical, and electrical properties of Bi2MoO6 ceramics via lanthanide doping and rGO integration for photo-degradation of Methylene Blue and Ciprofloxacin

Herein, lanthanide ion (Gd+3) doped Bismuth Molybdate (Bi2MoO6) integrated on the rGO sheets has been prepared as a novel photocatalyst (Gd@Bi2MoO6/rGO) for the photocatalytic treatment of toxic pollutants. Different physiochemical, optical, electrical, thermal, and electrochemical properties of Gd@Bi2MoO6/rGO, along with its counterparts (Bi2MoO6 and Gd@Bi2MoO6), were studied through XRD, SEM/TEM, FT-IR, UV/Vis, I-V, TGA, Mott-Schottky, and EIS measurements. Photocatalytic experiments revealed that Gd@Bi2MoO6/rGO exhibited significantly enhanced photocatalytic activity, achieving 96.2 % photo-degradation of Methylene Blue with 120 min of irradiation, which is 6.5 and 3.1 times higher compared to Bi2MoO6 (40.9 %) and Gd@Bi2MoO6 (64.8 %), respectively. Moreover, Gd@Bi2MoO6/rGO demonstrated a notable photocatalytic efficiency of 81.7 % towards Ciprofloxacin, significant as per the existing literature benchmark. The enhanced photocatalytic activity is ascribed to the in-built Gd+3 redox centers, high electrical conductivity (7.35 × 10−3 S/m), favorable flat band potential (-0.81 V), and low semiconductor impedance (Rct = 51.71 Ω and Rs = 0.90 Ω). Additionally, the electron-capturing ability of lanthanide dopant ions and S-C heterojunction of Gd@Bi2MoO6/rGO facilitates the separation of photo-generated e-/h+ pairs and favors high concentrations of ROS. The results obtained highlight the potential of Gd@Bi2MoO6/rGO for applications in photocatalysis and wastewater treatment.

Synergistic Nanoarchitectonics: Precision Membrane Engineering for Rare Earth Selective Separation

AbstractRare earth elements (REEs) are vital in high‐tech industries and defense due to their strategic significance. Crafting an efficient membranes channel for REE separation poses a significant challenge. Employing 2‐methylimidazole‐hydrolyzed OH−, dopamine polymerization is initiated and then Zn2+ coordinates with 2‐methylimidazole on PDA surfaces. The confined symbiotic reaction yields 2D vertical heterojunctions of GO/ZIF‐8/PDA (G/Z/P). During separation, partially dehydrated smaller hydrated lanthanide ions preferentially access interlayers, expanding and stabilizing the interlayer space by coordinating with PDA, thus excluding larger hydrated scandium ions from the membranes. Some scandium ions entering interlayer channels are sequestered by N in size‐matched ZIF‐8 pores. This distinctive mechanism facilitates selective scandium separation from other REEs (other REEs/Sc selectivity ≈68.73), achieving nearly complete Sc3+ rejection in a single step. The methodology offers unprecedented insights into precise nano‐space material synthesis, indicating promising strides in advancing scandium production.

Wearable, Biocompatible, and Dual-Emission Ocular Multisensor Patch for Continuous Profiling of Fluoroquinolone Antibiotics in Tears.

The abuse or misuse of antibiotics in clinical and agricultural settings severely endangers human health and ecosystems, which has raised profound concerns for public health worldwide. Trace detection and reliable discrimination of commonly used fluoroquinolone (FQ) antibiotics and their analogues have consequently become urgent to guide the rational use of antibiotic medicines and deliver efficient treatments for associated diseases. Herein, we report a wearable eye patch integrated with a quadruplex nanosensor chip for noninvasive detection and discrimination of primary FQ antibiotics in tears during routine eyedrop treatment. A set of dual-mode fluorescent nanoprobes of red- or green-emitting CdTe quantum dots integrated with lanthanide ions and a sensitizer, adenosine monophosphate, were constructed to provide an enhanced fluorescence up to 45-fold and nanomolar sensitivity toward major FQs owing to the aggregation-regulated antenna effect. The aggregation-driven, CdTe-Ln(III)-based microfluidic sensor chip is highly specific to FQ antibiotics against other non-FQ counterparts or biomolecular interfering species and is able to accurately discriminate nine types of FQ or non-FQ eyedrop suspensions using linear discriminant analysis. The prototyped wearable sensing detector has proven to be biocompatible and nontoxic to human tissues, which integrates the entire optical imaging modules into a miniaturized, smartphone-based platform for field use and reduces the overall assay time to ∼5 min. The practicability of the wearable eye patch was demonstrated through accurate quantification of antibiotics in a bactericidal event and the continuous profiling of FQ residues in tears after using a typical prescription antibiotic eyedrop. This technology provides a useful supplement to the toolbox for on-site and real-time examination and regulation of inappropriate daily drug use that might potentially lead to long-term antibiotic abuse and has great implications in advancing personal healthcare techniques for the regulation of daily medication therapy.

Halogen-Bonds-Based Strategy for the Design of Highly Luminescent Lanthanide Coordination Polymers as Taggants for Plastic Waste Sorting.

Reactions in water between a lanthanide ion and 3,4,5,6-tetrachloro-phthalate lead to a new series of iso-structural coordination polymers with general chemical formula [Ln2(tcpa)3(H2O)6]∞ with Ln = Eu-Yb plus Y. The crystal structure has been solved on the Y-derivative. This compound crystallizes in the monoclinic system, space group P21/n (no. 14) with the following cell parameters: a = 6.2155(2) Å, b = 19.6652(7) Å, c = 30.3720(9) Å, β = 94.631(1)°, V = 3700.22(37) Å3, and Z = 4. Luminescence properties of homo- and heterolanthanide coordination polymers that belong to this structural family have been studied in detail. This study shows that, in this system, intermetallic energy transfers are very efficient and that dilution by an optically non active Gd3+ ion leads to quite efficient luminescent heterolanthanide coordination polymers. The luminescence of these compounds, dispersed at a low doping rate in a poly(methyl methacrylate) (PMMA) matrix, can be observed even with the naked eye. This study opens the way to the use of such compounds as taggants for optical sorting of plastic waste and consecutive recycling.

Aggregation-Augmented Magnetism of Lanthanide-Doped Nanoparticles and Enabling Magnetic Levitation-Based Exosome Sensing.

Due to the presence of unpaired electron orbitals in most lanthanide ions, lanthanide-doped nanoparticles (LnNPs) exhibit paramagnetism. However, as to biosensing applications, the magnetism of LnNPs is so weak that can hardly be employed in target separation. Herein, it is discovered that the magnetism of the LnNPs is highly associated with their concentration in a confined space, enabling aggregation-augmented magnetism to make them susceptive to a conventional magnet. Accordingly, a magnetic levitation (Maglev) sensing system is designed, in which the target exosomes can specifically introduce paramagnetic LnNPs to the microbeads' surface, allowing aggregation-augmented magnetism and further leverage the microbeads' levitation height in the Maglev device to indicate the target exosomes' content. It is demonstrated that this Maglev system can precisely distinguish healthy people's blood samples from those of breast cancer patients. This is the first work to report that LnNPs hold great promise in magnetic separation-based biological sample sorting, and the LnNP-permitted Maglev sensing system is proven to be promising for establishing a new generation of biosensing devices.

Effects of interlayer spacing and applied pressure on the lanthanide transport in MoS2-based two-dimensional channels

ABSTRACT Rare-earth elements (REEs) are critical to modern industry but difficult to separate due to their subtle and monotonic changes in physicochemical properties. MoS2-based two-dimensional (2D) materials offer novel opportunities for enhancing REE separation, exhibiting a distinct volcano-shaped transport performance distribution that peaks at Sm3+. However, the specific contributions of thermodynamic and kinetic factors to ion transport within 2D confinement remain unclear. In this study, we conducted a series of non-equilibrium all-atom molecular dynamics (MD) simulations to explore the effects of interlayer spacing and external pressure on the transport of lanthanide ions in Å-scale acetate functionalized 2D MoS2 (MoS2-COOH) channels. We examined ion entry and permeation rates, water flux, dehydration, and binding modes. The simulation results reveal that the transport trends of lanthanide ions are jointly driven by the dehydration degree and the relative-binding strengths of ions to water and to the acetate within the 2D channels. Notably, the dehydration pattern of lanthanide ions during permeation is closely linked to kinetic factors. Overall, this study provides a detailed atomistic understanding of the mechanisms underlying lanthanide ion transport under confinement. These findings point to the significant potential for tuning confinement and chemical functionalization within Å-scale channels for more efficient REE separation.

Synthesis, spectroscopic characterization and biological activities of complexes of light lanthanide ions with 3-hydroxyflavone

New solid compounds of light lanthanide ions with 3-hydroxyflavone were synthesized in good yields (up to 85 %). The resulting complexes have been thoroughly characterized using various analytical and spectral techniques, including elemental analysis, complexometry, thermogravimetry, UV–VIS, FT-IR, 1H NMR, 109AgNPET LDI MS and fluorescence spectroscopy. The molecular formulas of the complexes were determined as follows: Ln(3HF)3, where 3HF-3-hydroxyflavone, Ln = La(III), Pr(III), Nd(III) and Ln(3HF)3·nH2O, where n = 1 for Ln = Ce(III), Sm(III), Eu(III), and n = 2 for Gd(III). Thermogravimetric studies revealed that the water molecules in the hydrated compounds are located in the outer coordination sphere. Based on the spectral data, it was noted that lanthanide ions interacted with the 3OH and 4CO groups of 3-hydroxyflavone. The effect of lanthanide ion chelation on the excited-state intramolecular proton transfer (ESIPT) process and fluorescence emission of 3HF was investigated. It was found that coordination with metal ions can suppress the ESIPT process and enhance the fluorescence emission of 3HF. The synthesized compounds were also screened for their antibacterial activity, free radical scavenging capacity, and interaction with BSA. The results showed that the complexes exhibit higher biological activity compared to the ligand.

Development of new calibrating material for luminescence spectrometer from Eu3+ doped aluminum sodium calcium borate glass

The calibration standards are formulated to correct emissions spectra and systematically monitor sensitivity fluctuations in luminescence spectrometers. This study outlines the development of luminescence calibration standards utilizing glass doped with lanthanide ions, specifically focusing on Eu3+ ions chosen for their robust emission properties. Glasses composed of aluminum calcium sodium borate doped with Eu3+ ions were prepared using the melt-quenching technique, with varying compositions of 20Al2O3–20CaO–20Na2O–(40–x)B2O3–xEu2O3 (where x = 0.0, 0.5, 1.0, 3.0, 5.0, and 7.0 mol%). The intense red emission around 615 nm through the 5D0 to 7F2 transition of Eu3+ was detected. To ensure measurement reliability, this study conducted measurements under four different stimulations: ultraviolet–visible light (photoluminescence), X–ray (radioluminescence), proton (protonluminescence), and electron (cathodoluminescence), verifying consistent peak positions. The findings from this study validate the potential of aluminum sodium calcium borate glasses doped with Eu3+, particularly those containing 3.0 mol% of Eu2O3, as effective calibration materials for luminescence spectrometers. This highlights their capability for accurate and consistent calibration, emphasizing their importance in maintaining measurement precision in the luminescence spectrometer.

Synthesis and Spectral Properties of Conjugated Bis-1,3-diketo Derivatives of Calix[4]arene in the 1,3-alternate Isomeric Form and Their Complexes with Eu3+

Distally substituted bis-1,3-diketone derivatives of calix[4]arene were synthesized, in which chelate groups are attached via a carbonyl carbon atom to the p-positions of phenolic fragments of a macrocycle fixed in 1,3-alternate isomeric form. 1,3-Diketone derivatives were obtained by acylation of magnesium enolate of a calix[4]arene ketone with 1-benzoylbenzotriazoles. In the synthesized compounds, 1,3-diketone groups are conjugated with the π-aromatic system of calix[4]arene. It was found by means of UV spectroscopy and NMR diffusion methods in combination with quantum chemical (DFT) calculations that a mononuclear complex with bis-chelate coordination of the lanthanide ion is predominantly formed in the solution. The formation of the complex leads to a decrease in the conjugation degree in the ligand. The most effective sensitization of Eu3+ luminescence, compared to the p-F- or p-CF3-phenyl-substituted complexes is observed for calix[4]arene complexes with H-phenyl-substituted 1,3-diketone groups.

Fabrication of a two-dimensional bi-lanthanide metal-organic framework as a ratiometric fluorescent sensor based on energy competition

Bimetallic lanthanide metal-organic frameworks (bi-Ln-MOFs) exhibit great appeal for ratiometric luminescent sensors due to their unique advantages. Specially, the low-lying energy of the empty 4f band of Ce4+ ions benefits Ce-MOFs with robust and broad fluorescent emission. Therefore, constructing ratiometric sensors based on Ce-MOFs is of significance but remains a challenge. Here, a two-dimensional (2D) bi-Ln-MOF is fabricated using Eu3+/Ce4+ and 5-boronoisophthalic acid (5-bop) via a crystal phase transformation strategy to construct a ratiometric luminescent Hg2+ sensor. Due to the lower energy gap of Ce4+ compared to Eu3+ and the corresponding stronger energy-absorption ability, the Ce4+ in bi-Ln-MOF shows a stronger and broader fluorescent emission than that of Eu3+. The substitution of the boric acid group in the bi-Ln-MOF by Hg2+ amplifies the difference between the two lanthanide ions. Therefore, the fluorescence intensity of Ce4+ increases whereas that of Eu3+ decreases accordingly, a behavior distinct from individual Eu-MOF or Ce-MOF performance. This novel bi-Ln-MOF sensor not only achieves a wide linear response range from 0.5 to 120 μM with a low detection limit of 167 nM for Hg2+, but also demonstrates exceptional selectivity and stability. The intriguing sensing mechanism of energy competition and the novel synthesis approach for 2D bi-Ln-MOF are anticipated to broaden the application possibilities of bi-Ln-MOFs for designing ratiometric sensors.

Exploring the Spatial Arrangement of Simple 18-Membered Hexaazatetraamine Macrocyclic Ligands in Their Metal Complexes.

Hexaazamacrocyclic Schiff bases have been extensively combined with lanthanoid (Ln) ions to obtain complexes with a highly axial geometry. However, the use of flexible hexaazatetraamine macrocycles containing two pyridines and acyclic spacers is rather uncommon. Accordingly, we obtained [DyL(OAc)2]OAc·7H2O·EtOH and [DyLMe2(Cl)2]Cl·2H2O, where L and LMe2 are the 18-membered macrocycles 3,6,10,13-tetraaza-1,8(2,6)-dipyridinacyclotetradecaphane and 3,10-dimethyl-3,6,10,13-tetraaza-1,8(2,6)-dipyridinacyclotetradecaphane, respectively, which contain ethylene and methylethylene spacers between their N3 moieties. [DyL(OAc)2]OAc·7H2O·EtOH represents the first crystallographically characterized lanthanoid complex of L, while [DyLMe2(Cl)2]Cl·2H2O contributes to increasing the scarce number of LnIII compounds containing LMe2. Furthermore, the crystal structure of L·12H2O was solved, and it was compared with those of other related macrocycles previously published. Likewise, the crystal structures of the DyIII complexes were compared with those of the lanthanoid and d-metal complexes of other 18-membered N6 donor macrocycles. This comparison showed some effect of the spacers employed, as well as the influence of the size of the ancillary ligands and the metal ion. Additionally, the distinct folding behaviors of these macrocycles influenced their coordination geometries. Moreover, the luminescent properties of [DyL(OAc)2]OAc·7H2O·EtOH and [DyLMe2(Cl)2]Cl·2H2O were also investigated, showing that both complexes are fluorescent, with the emission being sensitized by the ligands.

Synthesis, structure, and magnetic properties of lanthanide(III) complexes incorporating a tris-chelate cobalt(III) complex as a metalloligand

A series of CoIII–LnIII–CoIII trinuclear complexes [Ln{Co(Hmtimn)3}2](NO3)3 were prepared by following a simple one-pot synthesis method, mixing an unsymmetrical bidentate ligand 2-(2-imidazolinyl)-6-methoxypheol (H2mtimn) with Co(NO3)2·6H2O and LnX3· 6H2O (where Ln = La, Ce, Pr, Nd, Gd or Dy and X = NO3 − or Cl−) in methanolic solution in the presence of triethylamine in air. In the reaction mixture, this leads to the in situ formation of a tris-chelate CoIII metalloligand unit, which can coordinate LnIII ions through the interactions of phenolato- and methoxy-O donors. X-ray structural analysis revealed that the CoIII metalloligand functions as a rigid tripodal ligand to coordinate to a LnIII ion by six oxygen donors. The two metalloligands in the complex exhibit homochiral aggregation (ΔΔ or ΛΛ) upon coordination to the LnIII ion. The coordination of the central LnIII ion was found to be a distorted icosahedral geometry. Magnetic susceptibility measurements reveal that both cobalt and central lanthanide ions exist in trivalent states.

Simultaneously boosting visible and near-infrared luminescence of Ho in Cs2AgInCl6 double perovskites via Bi3+ sensitization

The emergence of near-infrared (NIR) luminescence from lanthanide (Ln3+) ions doped lead-free Cs2AgInCl6 double perovskites (DPs) has garnered significant attention due to its extensive range of potential applications. Unfortunately, they still suffer from weak NIR emission due to the inherent wide band gap of DPs resulting in inefficient energy transfer from the host to Ln3+. Herein, Bi3+ can act as the sensitizer to activate Ho3+ emission and reduce the excitation energy in Cs2AgInCl6: Ho. Under 400 nm excitation, Bi3+ co-doped Cs2AgInCl6: Ho shows 39 times and 21 times higher emission intensity than Cs2AgInCl6: Ho in Visible and NIR. As a result, a photoluminescence quantum yield of 18.63 % ranging from 800 to 1600 nm can be obtained. Finally, by coupling a Bi-doped sample with a commercial near-ultraviolet LED chip (395 nm), a compact Vis-NIR ultrawideband light source was prepared, which has promising applications in multifunctional illumination and night vision.