A new carboxylic acid, 2-cyano-3,3-diphenyl-2-propenoic acid, CLN, a chromophore ligand, was obtained by an alkaline hydrolysis reaction from the octocrylene, a commercial type B ultraviolet (UVB) ...radiation absorber. The CLN structure was elucidated by single-crystal X-ray diffraction (SCXRD) as being tetragonal with space group P4‾21/c and the presence of a carboxylic acid group was confirmed by mass, infrared (IR), and proton nuclear magnetic resonance (1H NMR) spectroscopy. In this way, coordination compounds were developed between CLN and Ln(III), Ln = being Gadolinium (Gd) and Europium (Eu), with a stoichiometry of 4:13 metal:ligand, confirmed by thermal and elemental analyses, corroborating with the metal cluster predicted by Sparkle/AM1 semi-empirical model. Photoluminescence data indicated that Eu(III) is efficiently sensitized by CLN due to its triplet excited state, determined using the emission spectrum of the Gd(III) mimic complex (T = 25,477 cm−1), being suitable for this purpose. Therefore, the emission spectrum of the Eu(III) complex exhibited a 5D0 → 7FJ transitions characteristic of the lanthanide ion. Furthermore, the Judd-Ofelt intensity parameters, the radiative and non-radiative decay rates, and the intrinsic quantum yield evaluated using the software LUMPAC software were in good agreement with the experimental values.
The alkaline hydrolysis of octocrylene provides the 2-cyano-3,3-diphenyl-2-propenoic acid, denoted as CLN, a novel potential antenna ligand; Europium(III) and Gadolinium(III) metal clusters have been prepared from CLN ligand; Semi-empirical methods yield the structure of the ground state and triplet state of the synthesized gadolinium complexes in agreement with experimental data. Display omitted
•The alkaline hydrolysis of octocrylene provides the 2-cyano-3,3-diphenyl-2-propenoic acid, denoted as CLN, a potential antenna ligand.•Europium(III) and Gadolinium(III) metal clusters have been prepared from CLN ligand.•Semi-empirical methods yield the structure of the ground state and triplet state of the gadolinium complexes in agreement with experimental data.
•Lanthanide molecular probes are promising candidates for NIR bioimaging and biosensing.•We summarized the design, synthesis and applications of lanthanide complexes for bioimaging.•Lanthanide ...complexes will be the next generation biomedical theranostic agents.
Recent advances in NIR detector bloom the design of NIR fluorophores for bioimaging guided diagnosis and therapeutics, with reduced light-tissue interaction, enhanced signal-to-noise ratio and increased penetration depth. NIR lanthanide molecular probes represent an important and emerging group of NIR imaging and sensing materials with attractive structural and photophysical characteristics including small sizes, metal-centered emission, long decay lifetime, large Stokes shift and high resistance to photobleaching. In this review, the sensitization of lanthanides and design principle of lanthanide molecular probes were described. We summarized the recent progresses in last decade on NIR luminescent lanthanide molecular probes by precisely tuning the antenna ligands. The development tendency of applying lanthanide molecular probes for in vivo bioimaging and biosensing would also be discussed, showing the unique and attractive properties of lanthanide coordination compounds compared to organic molecules and inorganic quantum nanoparticles.
•2,6-dimethoxy-4-methylphenol was used as a ligand for fluorescence detection for the first time.•Complex shows fluorescence sensitive response even under interference conditions.•Fluorescence ...detection can work across pH 4-10.
Anthrax is a potentially highly lethal acute infectious disease caused by the zoonotic bacterium Bacillus anthracis, which poses a threat to human life and health. 2, 6-Pyridinedicarboxylic acid (DPA) is a significant component of bacterial spores as a typical anthrax biomarker. Therefore, it is imperative to develop a simple and efficient detection method for DPA. Here, we successfully synthesized a binuclear terbium complex with formulas Tb2(DMOMP)2(CH3OH)2(H2O)4Cl2·2Cl·2CH3OH, which is constructed by 2, 6-dimethoxy-4-methylphenol (DMOMP) and TbⅢ ion. Each TbⅢ ion center is encapsulated by seven O atoms and one Cl− anion. Based on this, the encapsulated coordination environment facilitated efficient ligand energy transfer via the “antenna effect”. Therefore, the complex exhibits interesting luminescence response characteristics, with fast and stable green fluorescence response to DPA, low detection limit Ksv = 1.08 × 10−5 M−1, and fluorescence lifetime τ = 754.93 μs. Tb2(DMOMP)2(CH3OH)2(H2O)4Cl2·2Cl·2CH3OH has excellent fluorescence properties and strong immunity to interference and is capable of sensitively detecting the B. anthracis biomarker DPA, allowing it to be potentially used as an effective fluorescent probe and providing a viable strategy for effective anthrax fever prevention.
In this work, a binuclear TbⅢ complex bridged by phenoxyl O atom is prepared and used for the fluorescent detection of 2, 6-pyridindicarboxylic acid, an anthrax biomarker with certain anti-interference. Display omitted
Octacoordinated ternary heteroleptic lanthanide (Sm and Tb) complexes have been synthesized with diacetylmethane (DAM) and substituted 1,10-phenanthroline auxiliary units. The synthesized complexes ...were thoroughly characterized through electrochemical, thermal and spectroscopic studies. Photoluminescence emission spectral profiles have demonstrated green and orange-red emission due to the characteristic 5D4 → 7F5 and 4G5/2 → 6H9/2 transitions of Tb3+ and Sm3+ ions, respectively. Intensity ratio points out the asymmetric site around respective trivalent ion which leads to intense luminescence. The energy transfer mechanism has revealed the efficient sensitization of metal ions through organic ligand DAM. Photophysical and optical properties affirm the luminous and conducting behavior of synthesized complexes. These luminous lanthanide complexes could be utilized as emissive material in fabricating display devices.
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•A series of bright emissive Tb(III) and Sm(III) complexes were prepared with diacetylmethane diketone and heteroaromatic auxiliary ligands.•Emission spectral profiles exhibit intense hypersensitive peaks attributed to 5D4 .→ 7F5 and 4G5/2 → 6H9/2 transitions of Tb3+ and Sm3+ ions, respectively.•Luminescent intensity and color parameters are superior in solid state.•The band gap and branching ratio measurements confirm their potential utility in laser diodes.
Our previous experimental observations show that the crystal structure of lanthanide luminescent complexes synthesized in aqueous solution usually contains a large number of coordination water ...molecules or free water molecules. In order to probe the influence of water molecules on luminescent processes of lanthanide complexes, the photoluminescence properties of Ln-FBA (Ln = Eu and Tb, FBA = p-fluorobenzoic acid) coordination polymers at different ambient temperatures, in different solvents and aqueous DMSO solutions with different volume concentrations were systematically investigated. The experiment results show that the presence of water molecules can promote the energy transfer from FBA ligand to Ln3+, at the same time, can cause luminescent non-radiation quenching of lanthanide ions. In addition, the variation of emission intensity ratio of 615 nm/591 nm peaks of Eu3+ with increasing the volume concentration of H2O can be potentially used for the quantitatively detection of water traces in organic solvents. In order to suppress the non-radiation quenching caused by the water molecules, Ln-FBA (Ln = Eu and Tb) coordination polymers were embedded into the PVP matrix to prepare Ln-FBA@PVP hybrid materials. The photoluminescence investigation indicates that PVP can not only block the quenching effect of water molecules on luminescence, but also effectively sensitize Eu3+ and Tb3+ luminescence. These experimental conclusions are useful for probing the influence of water molecules on luminescent processes of lanthanide complexes, quantitatively detecting water traces in organic solvents and enhancing the photoluminescence intensity in lanthanide complexes.
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•The effects of H2O on luminescent processes of Ln-FBA complexes were investigated.•H2O can promote FBA→Ln3+ energy transfer and cause luminescent quenching of Ln3+.•PVP can suppress the quenching effect of H2O and sensitize Ln3+ luminescence.
•Nine dinuclear lanthanide (III) complexes were synthesized and characterized.•Single crystal X-ray structure of Dy2(L)2(NO3)4 is discussed.•In vitro antibacterial activities of compounds were ...identified.•Antioxidant activities of compounds were evaluated using DPPH.
A series of lanthanide(III) complexes containing Schiff base ligand, NEt32Ln2(L)2(NO3)4⋅xH2O {Ln, x: La,1; Pr, 2, Nd, 1; Sm, 1; Eu, 1; Gd, 1; Tb, 2; Dy, 2; and Er, 4; H2L: (E)-N'-(3,5-di-tert-butyl-2-hydroxybenzylidene)picolinohydrazide Schiff Base Ligand}, have been synthesized by reaction of H2L with Ln(NO3)3⋅xH2O salts {Ln, x: La, 6; Pr, 6; Nd, 6; Sm, 6; Eu, 5; Gd, 6; Tb, 5; Dy, 6; Er, 5} in the presence of Et3N. The structures of these compounds have been characterized by elemental analysis, thermal gravimetric, molar conductivity, and different spectral analysis techniques (IR, UV–vis, 1H, and 13CNMR ). Each unit of the anionic part comprises one Ln3+ ion, one bi-basic L2− ligand, and two bidentate nitrate NO3− groups. Each Ln3+ ion is coordinated by one pyridyl N atom, two alkoxido O atoms, one azomethine N atom, and one phenolate O atom. The lanthanide centers in the dinuclear core are bridged by two alkoxide groups from two ligands. The molar conductivity results have indicated that each of these complexes is a 2:1 electrolyte. Dy_L complex obtained from a mixture of MeCN/DMF solution has also been structurally characterized via X-ray diffractometry. The solid-state structure of the Dy_L complex revealed that the asymmetric unit of Dy_L is formulated from Dy3+ ion, one L2− ligand, one bi-dentate nitrate NO3− group, and one coordinated DMF molecule. The results of antioxidant activities have shown that all investigated complexes are more efficient in quenching DPPH• than the free H2L. Antibacterial activities have also been investigated against some Gram-negative bacteria and Gram-positive bacteria. The MIC values have reflected that all complexes have moderate antibacterial activity against the examined Gram-negative bacteria. On the contrary, they are inactive against the examined Gram-positive bacteria.
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•The design principles for luminescent probes based on lanthanide complexes are summarized.•Recognition mechanisms of luminescent probes based on lanthanide complexes for various ...analytes are described.•The effects of the types of lanthanide nanoparticles on the luminescence sensing behaviors are highlighted.
Lanthanide-based luminescent probes have attracted increasing attention due to their unique optical properties, such as large Stokes and/or anti-Stokes shifts, long luminescence lifetimes (up to milliseconds), and narrow and compound-independent emission bands, making them widely employed in detection, diagnosis, and bioimaging. This review focuses on the recent developments of lanthanide-based luminescent probes including lanthanide complexes and lanthanide nanoparticles for probing pH, anions, metal ions, reactive oxygen species, and biomolecules (amino acids, proteins, nucleobases, and nucleic acids). The design principles and recognition mechanisms of luminescent probes based on lanthanide ions for various analytes are elaborated in detail. In the end, future research directions with great potentials and the according challenges of lanthanide-based luminescent probes are also discussed.
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•Lanthanide-based luminescent hybrid materials show multifunctional behavior.•They have potential applications in sensors, LEDs, security inks, and solar cells.•Upconverting hybrid ...materials could be used in bioimaging and anticounterfeiting.•They can enhance UV stability and the efficiency of halide perovskite devices.
Lanthanide-based luminescent hybrid materials (also known as lanthanide complexes) comprise organic moieties (mostly, β-diketones) as sensitizers and inorganic lanthanide ions as activators, which seeks to address the weak luminescence of lanthanide ions. In these materials, organic moieties (ligands) work as an antenna that strongly absorbs ultraviolet/near-infrared radiation in a broad spectral range and efficiently transfers its excitation energy to the central lanthanide ions that produce its characteristic emission. In recent years, lanthanide-based luminescent hybrid materials have witnessed a surge in research interest in various fields namely luminescence-based sensing, light-emitting diodes, luminescence-based security inks, bioimaging, and increasing the stability/efficiency of halide perovskite-based optoelectronic devices. The near-infrared dye-sensitized hybrid upconverting material is a recent development in the field and is relatively less explored. The halide perovskite, which is a hot topic of research in the field of optoelectronic devices faces the challenge of poor stability under UV light and ambient conditions. In recent years, it has been shown that lanthanide-based luminescent hybrid materials can be used to increase the stability and efficiency of halide perovskite-based optoelectronic devices. This comprehensive review covers energy harvesting in lanthanide-based hybrid materials and its applications in various fields. The multifunctional behavior of lanthanide-based luminescent hybrid materials is demonstrated by considering a few examples in each application area along with in-depth discussion. An emphasis was made on lanthanide-based upconverting hybrid materials and the effect of lanthanide-based hybrid materials on the efficiency and photostability of halide perovskite optoelectronic devices, which are recent developments in the field and therefore less documented.
Tribo‐excitation in a crystalline compound is an interesting phenomenon in which a mechanical stimulus drives the compound to its excited state. We demonstrate a tribo‐excited chemical reaction using ...trivalent europium (EuIII) and gadolinium (GdIII) complexes with stacked anthracene ligands for the development of tribo‐excitation chemistry. The tribo‐oxidation and ‐dimerization reactions in the stacked anthracene ligands occur in the EuIII and GdIII complexes, respectively. More information can be found in the Research Article by Y. Kitagawa, Y. Hasegawa et al. (DOI: 10.1002/chem.202104401).
Two new complexes Ln(2-Cl-6-FBA)2(terpy)(NO3)(H2O)2, (Ln = Sm(1), Gd(2), 2-Cl-6-FBA = 2-chloro-6-fluorobenzoate, terpy = 2,2′:6′2″-tripyridine) were successfully synthesized by volatilization ...in ambient solution. The two complexes were isostructural, and 1D chain and 2D faceted supramolecular structures were mapped. An elemental analysis, IR, Raman spectroscopy, PXRD, TG analysis, and a 3D infrared escape gas study were carried out to characterize the complexes. The fluorescence properties of complex 1 were studied. 4G5/2-6H7/2 at 601 nm was the strongest characteristic transition peak. Finally, the corresponding polynomial equation for the heat capacity(y)-temperature(x) of the complex was obtained using a least-squares fit. The smoothed heat capacities and thermodynamic functions for complexes 1 and 2 were calculated by fitted polynomial and thermodynamic equations.
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•Two novel lanthanide complexes have been successfully synthesized.•The thermal decomposition mechanism was studied by TG-DSC/FTIR.•The luminescent properties for complex 1 was investigated.•The molar heat capacity was determined and thermodynamic function was calculated.
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