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Imidodiphosphonate Ligands for Enhanced Sensitization and Shielding of Visible and Near-Infrared Lanthanides
摘要： The design of coordination sites around lanthanide ions has a strong impact on the sensitization of luminescent signal. An imidodiphosphonate anionic binding site is attractive as it can be functionalized with “remote” sensitizer units, such as phenoxy moieties, namely, HtpOp, accompanied by an increased distance of the lanthanide from the ligand high-energy stretching vibrations which quench the luminescence signal, hence providing flexible shielding of the lanthanide. We report the formation and isolation of Ln(tpOp)3 complexes where Ln = Er, Gd, Tb, Dy, Eu, and Yb and the Y(tpOp)3 diamagnetic analogue. The complexes are formed from reaction of KtpOp and the corresponding LnCl3·6H2O salt either by titration and in situ formation or by mixing and isolation. All complexes are seven-coordinated by three tpOp ligand plus one ethanol molecule, except for Yb(tpOp)3 which has no solvent coordinated. Phosphorus NMR shows characteristic shifts to support the coordination of the lanthanide complexes. The complexes display visible and near-infrared luminescence with long lifetimes even for the near-infrared complexes which range from 3.3 μs for Nd(tpOp)3 to 20 μs for Yb(tpOp)3. The ligand shows more efficient sensitization than the imidodiphosphinate analogues for all lanthanide complexes with a notable quantum yield of the Tb(tpOp)3 complex at 45%. We attribute this to the properties of the remote sensitizer unit and its positioning further away from the lanthanide, eliminating quenching of high energy C?H vibrations from the ligand shell. Calculations of the ligand shielding support the photophysical properties of the complexes. These results suggest that these binding sites are promising in the further development of the lanthanide complexes in optoelectronic devices for telecommunications and new light emitting materials.
关键词： sensitization,imidodiphosphonate,shielding,luminescence,lanthanide
更新于2025-09-12 10:27:22
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Quantitative Analysis of Cerium-Gallium Alloys Using a Hand-Held Laser Induced Breakdown Spectroscopy Device
摘要： A hand-held laser-induced breakdown spectroscopy device was used to acquire spectral emission data from laser-induced plasmas created on the surface of cerium-gallium alloy samples with Ga concentrations ranging from 0–3 weight percent. Ionic and neutral emission lines of the two constituent elements were then extracted and used to generate calibration curves relating the emission line intensity ratios to the gallium concentration of the alloy. The Ga I 287.4-nm emission line was determined to be superior for the purposes of Ga detection and concentration determination. A limit of detection below 0.25% was achieved using a multivariate regression model of the Ga I 287.4-nm line ratio versus two separate Ce II emission lines. This LOD is considered a conservative estimation of the technique’s capability given the type of the calibration samples available and the low power (5 mJ per 1-ns pulse) and resolving power (λ/?λ = 4000) of this hand-held device. Nonetheless, the utility of the technique is demonstrated via a detailed mapping analysis of the surface Ga distribution of a Ce-Ga sample, which reveals signi?cant heterogeneity resulting from the sample production process.
关键词： LIBS,plasma spectroscopy,analytical chemistry,nuclear forensics,nuclear chemistry,lanthanide spectroscopy
更新于2025-09-12 10:27:22
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Spectroscopic Characterization of Er,Yb:Y <sub/>2</sub> Ti <sub/>2</sub> O <sub/>7</sub> Nanoparticles for Forensic Applications
摘要： Fingerprint identification technology has been widely utilized in the forensic field, given that the fingerprint is unique for each person and each finger and does not vary with age. In general, the fingerprints at a crime scene are latent and difficult to collect if the fingers were not contaminated with coloured materials, such as blood, ink or pigment. Moreover, the fingerprints on a smooth plane or transparent glass are hard to be visualized with traditional methods. In recent years, luminescent lanthanide-based nano-powder has been explored as a potential aid in fingerprint detection. Lanthanide based nano-materials have been analyzed because of the optical properties arising from the intra 4f transitions and of their relatively low toxicity. In principle, the technique allows the detection of latent finger-marks on a broad range of surfaces, like porous, semi-porous, non-porous and aged finger-marks. For the successful application of up-conversion phosphors in latent finger-marks detection, a phosphor should have good emission efficiency, uniform particle morphology, a dusty nature and stability against the humid environment. Y2Ti2O7 (YTO) belongs to the pyrochlore class and possesses peculiar thermodynamic and dynamic magnetic properties and has drawn researchers’ attention also for its upconversion emission properties or for ion-detection. In this work, we report the successful preparation of novel and non-toxic powder based on highly luminescent Er3+ and Er3+/Yb3+ codoped YTO nano-phosphors for fingerprint detection through solid- state method. To this aim, crystal structure, luminescence properties, morphology, and optimal doping concentrations have been investigated. Furthermore, the energy transfer processes between Er3+ and Yb3+ ion have been studied as a function of the concentration of Er3+ ions. Moreover, we used the optimized doped and co-doped YTO phosphors to detect fingerprints on the surface of different objects among which we chose several items commonly used in daily life, such as glass and plastic, where fingerprints are often left. The results reveal that the co-doped phosphors can efficiently manifest latent fingerprints with high contrast and low background interference, holding important application in fingerprint identification.
关键词： Y2Ti2O7,luminescent lanthanide-based nano-powder,fingerprint identification,solid-state method,Yb3+,Er3+
更新于2025-09-11 14:15:04
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Modification of cellulose fibers with inorganic luminescent nanoparticles based on lanthanide(III) ions
摘要： This article presents synthesis and properties of the fibers modified with luminescent, inorganic nanoparticles doped with lanthanide(III) ions, i.e. LaF3:Ce3+, Gd3+, Eu3+, CeF3:Tb3+ and CePO4:Tb3+. The fibers with luminescent properties were prepared via so called Lyocell process. This method involves dissolving cellulose in aqueous solution of N-methylmorpholine-N-oxide (NMMO) and a subsequent spinning of the fibers, using a dry-wet method. Thanks to the successful incorporation of the modifier nanoparticles (NPs) into the cellulose matrices, the fibers exhibited bright, multicolor emission upon UV irradiation and good mechanical properties, which allowed further textile processing. This type of fibers, as well as the as-prepared textiles/fabric can be used as an anti-counterfeiting agent for clothes and documents protection.
关键词： Lanthanide(III) ions,Luminescence,Multifunctional cellulose fibers
更新于2025-09-11 14:15:04
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Comparison of spectral and thermal properties and antibacterial activity of new binary and ternary complexes of Sm(III), Eu(III) and Gd(III) ions with N-phenylanthranilic acid and 1,10-phenanthroline
摘要： New binuclear binary and ternary complexes of Sm(III), Eu(III), and Gd(III) ions with N-phenylanthranilic acid and 1,10-phenanthroline were obtained in solid phase and characterized by chemical and elemental analysis, molar conductance, UV–VIS and IR spectroscopies as well as thermoanalytical techniques (TG/DTG–DSC coupled with MS and FT-IR). The dilution method was used to examine the antibacterial activity of the synthesized compounds. The spectroscopic studies indicated that the carboxylate group of N-phenylantranilate ligand is involved in the coordination of metal ion, both in binary and ternary complexes. Thermal decomposition of the obtained compounds was carried out in air and nitrogen atmosphere. During heating, the complexes decompose via intermediate products to the oxide (Ln2O3) in air atmosphere and to the oxide (Ln2O3) or oxide polluted by carbon (Ln2O3+nC) in nitrogen atmosphere. The dehydration process was discussed in relation to the nature of water present in these compounds. Using coupled TG–FTIR–MS techniques the decomposition pathways of the synthesized compounds were examined. Additionally, gaseous products released during pyrolysis and thermal oxidation of the complexes were identified. All the complexes exhibit marked activity against two Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and one Gram-positive (Staphylococcus aureus) bacterial strains. The ternary complexes, especially Gd(III) complex in comparison with the binary ones, have enhanced activity against Escherichia coli. Moreover, antibacterial activity of the synthesized compounds with respect to Pseudomonas aeruginosa is comparable to tetracycline and greater than for kanamycin, erythromycin, and ampicillin.
关键词： 1,10-phenanthroline,Thermal analysis,Lanthanide complexes,N-phenylanthranilic acid,EGA
更新于2025-09-11 14:15:04
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White-Light Emitting Di-Ureasil Hybrids
摘要： White-light emitting materials have emerged as important components for solid state lighting devices with high potential for the replacement of conventional light sources. Herein, amine-functionalized organic-inorganic di-ureasil hybrids consisting of a siliceous skeleton and oligopolyether chains codoped with lanthanide-based complexes, with Eu3+ and Tb3+ ions and 4,4'-oxybis(benzoic acid) and 1,10-phenanthroline ligands, and the coumarin 1 dye were synthesized by in situ sol–gel method. The resulting luminescent di-ureasils show red, green, and blue colors originated from the Eu3+, Tb3+, and C1 emissions, respectively. The emission colors can be modulated either by variation of the relative concentration between the emitting centers or by changing the excitation wavelength. White light emission is achieved under UV excitation with absolute quantum yields of 0.148 ± 0.015, 0.167 ± 0.017, and 0.202 ± 0.020 at 350, 332, and 305 nm excitation, respectively. The emission mechanism was investigated by photoluminescence and UV–visible absorption spectroscopy, revealing an efficient energy transfer from the organic ligands to the Ln3+ ions and the organic dye, whereas negligible interaction between the dopants is discerned. The obtained luminescent di-ureasils have potential for optoelectronic applications, such as in white-light emitting diodes.
关键词： lanthanide complexes,di-ureasil organic–inorganic hybrids,in situ sol–gel synthesis,white light emission,coumarin 1
更新于2025-09-10 09:29:36
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Function-Oriented: The Construction of Lanthanide MOF Luminescent Sensors Containing Dual Function Urea Hydrogen Bond Sites for Picric Acid
摘要： Two novel lanthanide metal-organic framework (Ln-MOF) luminescent sensors for the detection of picric acid have been successfully assembled. Following the function-oriented research strategy, urea hydrogen bond functional sites were introduced into the MOF framework. The structural analyses indicate that the two MOFs have the same exact structure, both of which are 2D layers with diamond-shaped holes, which are accumulated into 3D framework by the interaction of urea and carboxylate hydrogen bonds. Interestingly, only half of the urea units is involved in support MOF framework in the form of N?H···O hydrogen bonding interactions, while the other half is located in the pore canal, thus reserving empty recognition sites. There are abundant N?H urea bonds in the inner walls of three types of interpenetration 1D channels. Luminescence studies revealed that the two Ln-MOFs exhibited high sensitivity, good selectivity and fast luminescence quenching response towards picric acid. Especially, the two Ln-MOFs can be simply and quickly regenerated, which exhibited excellent recyclability. We successfully use of function-oriented research strategy to achieve multiple functions with a ligand to construct lanthanide MOF luminescent sensors for the detection of picric acid, providing an idea for the development of clear purpose MOF luminescent sensors.
关键词： luminescent sensor,lanthanide MOF,function-oriented,recyclability,nitro explosives
更新于2025-09-10 09:29:36
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Lanthanide-Based Thermometers: At the Cutting-Edge of Luminescence Thermometry
摘要： Present technological demands in disparate areas, such as microfluidics and nanofluidics, microelectronics and nanoelectronics, photonics and biomedicine, among others, have reached to a development such that conventional contact thermal probes are not accomplished anymore to perform accurate measurements with submicrometric spatial resolution. The development of novel noncontact thermal probes is, then, mandatory, contributing to an expansionary epoch of luminescence thermometry. Luminescence thermometry based on trivalent lanthanide ions has become very popular since 2010 due to the unique versatility, stability, and narrow emission band profiles of the ions that cover the entire electromagnetic spectrum with relatively high emission quantum yields. Here, a perspective overview on the field is given from the beginnings in the 1950s until the most recent cutting-edge examples. The current movement toward usage of the technique as a new tool for thermal imaging, early tumor detection, and as a tool for unveiling the properties of the thermometers themselves or of their local neighborhoods is also summarized.
关键词： Luminescent Nanothermometers,Early Tumor Detection,Luminescence Thermometry,Lanthanide-Based Thermometers,Thermal Imaging
更新于2025-09-10 09:29:36
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Two novel Sm(III) complexes with different aromatic carboxylic acid ligands: Synthesis, crystal structures, luminescence and thermal properties
摘要： Two novel Sm(Ⅲ) complexes, [Sm(3,4-DMBA)3(3,4-DMHBA)(5,5′-DM-2,2′-bipy)]2 (1), [Sm(3-MOBA)3(5,5′-DM-2,2′-bipy)]2 (2) (3,4-dimethylbenzoic acid = 3,4-DMHBA, 3-methoxybenzoic acid = 3-MOHBA and 5,5′-dimethyl-2,2′-bipyridine = 5,5′-DM-2,2′-bipy), have been successfully synthesized and assembled. The crystal structures were determined by single crystal X-ray diffraction. Two complexes were characterized by the elemental analysis, IR, powder X-ray diffraction, thermal gravimetric technology. Because of the different ligands, the structures of the two complexes are very different, especially the structure of the complex 1. Each central Sm(Ⅲ) ion of complex 1 was coordinated by three deprotonated 3,4-DMBA-,one unprotonated 3,4-DMHBA and one 5,5′-DM-2,2′-bipy, which has rarely been reported before. However each central Sm(Ⅲ) ion of complex 2 was only coordinated via three deprotonated 3-MOBA- and one 5,5′-DM-2,2′-bipy. In addition, the thermal decomposition mechanism and the three-dimensional infrared accumulation spectra of the evolved gas during the thermal decomposition for two complexes were studied by the simultaneous TG/DSC-FTIR technology. What′s more, the luminescence properties of two complexes were also discussed. Finally, the bacteriostatic activities of two complexes were evaluated against Staphlococcus aureus, Escherichia coli and Candida albicans.
关键词： TG/DSC-FTIR,Crystal structure,Bacteriostatic activities,Lanthanide complexes,luminescence
更新于2025-09-10 09:29:36
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A series of lanthanide coordination polymers based on flexible bis?(imidazole?4,5?dicarboxylate) ligand: Syntheses, structures and fluorescent properties
摘要： A series of lanthanide coordination polymers, namely {[Ln(HL)(H2O)2]·H2O}n (Ln= Ce(1), Pr(2), Nd(3), Eu(4) and Tb(5); H4L = 1,1'-(propane-1,3-diyl)bis(1H-imidazole-4,5-dicarboxylic acid)) have been synthesized under hydrothermal conditions and characterized by infrared spectroscopy, element analysis, single-crystal X-ray diffraction, powder X-ray diffraction and thermogravimetric analyses. These isostructural complexes exhibit a 3D framework with a sra topology built by HL3? anions μ4?bridging metal ions through two IDC groups in different coordination modes. The luminescent property of complexes containing Eu(III) and Tb(III) have also been investigated in detail.
关键词： Lanthanide,Topology,Imidazole-4,5-dicarboxylic acid,Luminescence,Crystal structure
更新于2025-09-10 09:29:36