Biocompatible Silica-Coated Europium-Doped CsPbBr3 Nanoparticles with Luminescence in Water for Zebrafish Bioimaging.

Cesium lead halide (CsPbX3, X = Br, Cl, and I) nanocrystals (NCs) are widely concerned and applied in many fields due to the excellent photoelectric performance. However, the toxicity of Pb and the loss of luminescence in water limit its application in vivo. A stable perovskite nanomaterial with good bioimaging properties is developed by incorporating europium (Eu) in CsPbX3 NCs followed with the surface coating of silica (SiO2) shell (CsPbX3:Eu@SiO2). Through the surface coating of SiO2, the luminescence stability of CsPbBr3 in water is improved and the leakage of Pb2+ is significantly reduced. In particular, Eu doping inhibits the photoluminescence quantum yield reduction of CsPbBr3 caused by SiO2 coating, and further reduces the release of Pb2+. CsPbBr3:Eu@SiO2 nanoparticles (NPs) show efficient luminescence in water and good biocompatibility to achieve cell imaging. More importantly, CsPb(ClBr)3:Eu@SiO2 NPs are obtained by adjusting the halogen components, and green light and blue light are realized in zebrafish imaging, showing good imaging effect and biosafety. The work provides a strategy for advanced perovskite nanomaterials toward biological practical application.

The Role of Rare-Earth Atoms in the Anisotropy and Antiferromagnetic Exchange Coupling at a Hybrid Metal-Organic Interface.

Magnetic anisotropy and magnetic exchange interactions are crucial parameters that characterize the hybrid metal-organic interface, a key component of an organic spintronic device. It is shown that the incorporation of 4f RE atoms to hybrid metal-organic interfaces of CuPc/REAu2 type (RE = Gd, Ho) constitutes a feasible approach toward on-demand magnetic properties and functionalities. The GdAu2 and HoAu2 substrates differ in their magnetic anisotropy behavior. Remarkably, the HoAu2 surface promotes the inherent out-of-plane anisotropy of CuPc, owing to the match between the anisotropy axis of substrate and molecule. Furthermore, the presence of RE atoms leads to a spontaneous antiferromagnetic exchange coupling at the interface, induced by the 3d-4f superexchange interaction between the unpaired 3d electron of CuPc and the 4f electrons of the RE atoms. It is shown that 4f RE atoms with unquenched quantum orbital momentum ( L $L$ ), as it is the case of Ho, induce an anisotropic interfacial exchange coupling.

Spectral Hole-Burning Studies of a Mononuclear Eu(III) Complex Reveal Narrow Optical Linewidths of the 5D0→7F0 Transition and Seconds Long Nuclear Spin Lifetimes.

Coordination complexes of rare-earth ions (REI) show optical transitions with narrow linewidths enabling the creation of coherent light-matter interfaces for quantum information processing (QIP) applications. Among the REI-based complexes, Eu(III) complexes showing the 5D0→7F0 transition are of interest for QIP applications due to the narrow linewidths associated with the transition. Herein, we report on the synthesis, structure, and optical properties of a novel Eu(III) complex and its Gd(III) analogue composed of 2,9-bis(pyrazol-1-yl)-1,10-phenanthroline (dpphen) and three nitrate (NO3) ligands. The Eu(III) complex-[Eu(dpphen)(NO3)3]-showed sensitized metal-centred emission (5D0→7FJ; J=0,1,2,3, 4, 5, or 6) in the visible region, upon irradiation of the ligand-centred band at 369 nm, with the 5D0→7F0 transition centred at 580.9 nm. Spectral hole-burning (SHB) studies of the complex with stoichiometric Eu(III) concentration revealed a narrow homogeneous linewidth (Γh) of 1.55 MHz corresponding to a 0.205 µs long optical coherence lifetime (T2opt). Remarkably, long nuclear spin lifetimes (T1spin) of up to 41 s have been observed for the complex. The narrow optical linewidths and long T1spin lifetimes obtained for the Eu(III) complex showcase the utility of Eu(III) complexes as tuneable, following molecular engineering principles, coherent light-matter interfaces for QIP applications.

Regulating Electrostatic Interactions toward Thermoresponsive Hydrogels with Low Critical Solution Temperature.

Low critical solution temperature (LCST) of commonly used thermoresponsive polymers in water is basically dominated by hydrophobic interactions. Herein, a novel thermoresponsive system based on electrostatic interactions is reported. By simply loading aluminum chloride (AlCl3 ) into non-responsive poly(2-hydroxyethyl acrylate) (PHEA) hydrogels, PHEA-Al gels turn to have reversible thermoresponsive behavior between transparent and opaque without any volume change. Further investigations by changing metal ion-polymer compositions unravel the necessity of specific electrostatic interactions, namely, cation-dipole bonding interactions between hydroxy groups and trivalent metal ions. The thermoresponsive hydrogel demonstrates high transparency (≈95%), excellent luminous modulation capability (>98%), and cyclic reliability, suggesting great potential as an energy-saving material. Although LCST control by salt addition is widely known, salt-induced expression of thermoresponsiveness has barely been discussed before. This design provides a new approach of easy fabrication, low cost, and scalability to develop stimuli-responsive materials.

A comprehensive calibration of integrated magnetron sputtering and plasma enhanced chemical vapor deposition for rare-earth doped thin films.

A new integrated deposition system taking advantage of magnetron sputtering and electron cyclotron-plasma enhanced chemical vapour deposition (IMS ECR-PECVD) is presented that mitigates the drawbacks of each fabrication system. This tailor-made system provides users with highly homogeneous and pure thin films with less undesired hydrogen and well-controlled rare-earth concentration compared to existing methods of rare-earth doping, such as metalorganic powders, sputtering, and ion implantation. We established the first comprehensive report on the deposition parameters of argon flow and sputtering power to achieve desired rare-earth concentrations in a wide composition range of terbium (Tb) doped-silicon oxide (Tb:SiOx) matrices including silicon-rich (x < 2), oxygen-rich (x > 2), and stoichiometric silicon oxide (x = 2). The deposition parameters to fabricate crystalline structure (Tb2Si2O7) in oxygen-rich samples are reported where Tb ions are optically active. IMS ECR-PECVD pushes the solubility limit of the rare-earth dopant in silicon films to 17 at.% for the desired future nanophotonic devices. Supplementary Information: The online version contains supplementary material available at 10.1557/s43578-023-01207-2.

Enhanced Tribodegradation of a Tetracycline Antibiotic by Rare-Earth-Modified Zinc Oxide.

Tribocatalysis is an emerging advanced oxidation process that utilizes the triboelectric effect, based on friction between dissimilar materials to produce charges that can initiate various catalytic reactions. In this study, pure and rare-earth-modified ZnO powders (La2O3, Eu2O3, 2 mol %) were demonstrated as efficient tribocatalysts for the removal of the tetracycline antibiotic doxycycline (DC). While the pure ZnO samples achieved 49% DC removal within 24 h at a stirring rate of 100 rpm, the addition of Eu2O3 increased the removal efficiency to 67%, and La2O3-modified ZnO powder exhibited the highest removal efficiency, reaching 80% at the same stirring rate. Additionally, increasing the stirring rate to 300 and 500 rpm led to 100% DC removal in the ZnO/La case within 18 h, with the pronounced effect of the stirring rate confirming the tribocatalytic effect. All tribocatalysts exhibited excellent recycling properties, with less than a 3% loss of activity over three cycles. Furthermore, a scavenger assay confirmed the importance of superoxide radical generation for the overall reaction rate. The results of this investigation indicate that the rare-earth-modified ZnO tribocatalysts can effectively utilize mechanical energy to decompose pollutants in contaminated water.

Rare Earths-The Answer to Everything.

Rare earths, scandium, yttrium, and the fifteen lanthanoids from lanthanum to lutetium, are classified as critical metals because of their ubiquity in daily life. They are present in magnets in cars, especially electric cars; green electricity generating systems and computers; in steel manufacturing; in glass and light emission materials especially for safety lighting and lasers; in exhaust emission catalysts and supports; catalysts in artificial rubber production; in agriculture and animal husbandry; in health and especially cancer diagnosis and treatment; and in a variety of materials and electronic products essential to modern living. They have the potential to replace toxic chromates for corrosion inhibition, in magnetic refrigeration, a variety of new materials, and their role in agriculture may expand. This review examines their role in sustainability, the environment, recycling, corrosion inhibition, crop production, animal feedstocks, catalysis, health, and materials, as well as considering future uses.

Fluorine Doping Mediated Epitaxial Growth of NaREF4 on TiO2 for Boosting NIR Light Utilization in Bioimaging and Photodynamic Therapy.

By integrating TiO2 with rare earth upconversion nanocrystals (NaREF4), efficient energy transfer can be achieved between the two subunits under near-infrared (NIR) excitation, which hold tremendous potential in the fields of photocatalysis, photodynamic therapy (PDT), etc. However, in the previous studies, the combination of TiO2 with NaREF4 is a non-epitaxial random blending mode, resulting in a diminished energy transfer efficiency between the NaREF4 and TiO2. Herein, we present a fluorine doping-mediated epitaxial growth strategy for the synthesis of TiO2-NaREF4 heteronanocrystals (HNCs). Due to the epitaxial growth connection, NaREF4 can transfer energy through phonon-assisted pathway to TiO2, which is more efficient than the traditional indirect secondary photon excitation. Additionally, F doping brings oxygen vacancies in the TiO2 subunit, which further introduces new impurity energy levels in the intrinsic band gap of TiO2 subunit, and facilitates the energy transfer through phonon-assisted method from NaREF4 to TiO2. As a proof of concept, TiO2-NaGdF4 : Yb,Tm@NaYF4@NaGdF4 : Nd@NaYF4 HNCs were rationally constructed. Taking advantage of the dual-model up- and downconversion luminescence of the delicately designed multi-shell structured NaREF4 subunit, highly efficient photo-response capability of the F-doped TiO2 subunit and the efficient phonon-assisted energy transfer between them, the prepared HNCs provide a distinctive nanoplatform for bioimaging-guided NIR-triggered PDT.

Bimetallic Synergy Enables Silole Insertion into THF and the Synthesis of Erbium Single-Molecule Magnets.

The potassium silole K2 [SiC4 -2,5-(SiMe3 )2 -3,4-Ph2 ] reacts with [M(η8 -COT)(THF)4 ][BPh4 ] (M=Er, Y; COT=cyclo-octatetraenyl) in THF to give products that feature unprecedented insertion of the nucleophilic silicon centre into a carbon-oxygen bond of THF. The structure of the major product, [(µ-η8 : η8 -COT)M(µ-L1 )K]∞ (1M ), consists of polymeric chains of sandwich complexes, where the spiro-bicyclic silapyran ligand [C4 H8 OSiC4 (SiMe3 )2 Ph2 ]2- (L1 ) coordinates to potassium via the oxygen. The minor product [(µ-η8 : η8 -COT)M(µ-L1 )K(THF)]2 (2M ) features coordination of the silapyran to the rare-earth metal. In forming 1M and 2M , silole insertion into THF only occurs in the presence of potassium and the rare-earth metal, highlighting the importance of bimetallic synergy. The lower nucleophilicity of germanium(II) leads to contrasting reactivity of the potassium germole K2 [GeC4 -2,5-(SiMe3 )2 -3,4-Me2 ] towards [M(η8 -COT)(THF)4 ][BPh4 ], with intact transfer of the germole occurring to give the coordination polymers [{η5 -GeC4 (SiMe3 )2 Me2 }M(η8 -COT)K]∞ (3M ). Despite the differences in reactivity induced by the group 14 heteroatom, the single-molecule magnet properties of 1Er , 2Er and 3Er are similar, with thermally activated relaxation occurring via the first-excited Kramers doublet, subject to effective energy barriers of 122, 80 and 91 cm-1 , respectively. Compound 1Er is also analysed by high-frequency dynamic magnetic susceptibility measurements up to 106  Hz.

Facile Synthesis of Anhydrous Rare-Earth Trichlorides from their Oxides in Chloridoaluminate Ionic Liquids.

Wide applications of anhydrous rare-earth (RE) trichlorides RECl3 in organometallic chemistry, for the synthesis of optical and magnetic materials, and as catalysts require a facile approach for their synthesis. The known methods use or produce toxic substances, are complicated and have limited reliability and upscaling. It has been shown that task-specific ionic liquids (ILs) can dissolve many metal oxides without special reaction conditions at moderate temperature, making the metals accessible to downstream chemistry. Using imidazolium chloridoaluminate ILs, pure crystalline anhydrous RECl3 (RE=La-Nd, Sm-Dy) can be synthesized in one step from RE oxides in high yield. The Lewis acidic IL acts as solvent and reaction partner. The by-product [Al4 O2 Cl10 ]2- , which was detected spectroscopically, remains in solution. The reacted IL can be removed quantitatively by washing. ILs with various imidazolium cations and AlCl3 content and the effect of temperature and reaction time were tested.

Construction of Y-Doped BiVO4 Photocatalysts for Efficient Two-Electron O2 Reduction to H2 O2.

Photocatalytic hydrogen peroxide (H2 O2 ) production on BiVO4 photocatalysts using water and oxygen as raw materials is a green and sustainable process. However, the photocatalytic efficiency of pristine BiVO4 is limited by severe charge recombination. In this work, rare earth element Yttrium (Y) doped BiVO4 photocatalysts were fabricated by the hydrothermal method. In the photocatalytic H2 O2 production experiment, the optimized Y-doped BiVO4 photocatalyst produced 114 µmol g-1 h-1 of H2 O2 under simulated sunlight (AM1.5) irradiation, which is four times higher than production activity of pure BiVO4 (26 µmol g-1 h-1 ). Density functional theory (DFT) calculation revealed that Y doping can enhance oxygen adsorption on the BiVO4 photocatalyst surface. Mechanistic investigations suggest that the doping process induces the in situ formation of monoclinic/tetragonal BiVO4 heterojunction, which further promotes the photogenerated carriers separation efficiency.

Nanodiamond-promoted white light emission in Eu, Dy, and Cu-containing phosphate glass: quantitative analysis and colorimetric study.

A thorough analysis of glass containing Eu2 O3 and Dy2 O3 , or Eu2 O3 , Dy2 O3 , and CuO melted together with nanodiamond powder was pursued based on measurements of optical absorption, photoluminescence (PL) emission and excitation spectra, and colorimetry. Nanodiamond facilitated the stabilization of Cu+ and Eu2+ ions with blue-emitting characteristics that, along with yellow-emitting Dy3+ and red-emitting Eu3+ led to the white light-emitting glass. Novel intensity notations implemented in intensity-based spectral ratios, and difference intensity correlation analysis were proposed for the assessment of PL properties. The chromaticity and correlated colour temperature of the emission were ultimately investigated as a two-parametric problem based on: (1) the different ionic components; and (2) the various excitation wavelengths employed. The optical analysis approach adds to the characterization methods to further fundamental understanding and provide helpful analytical tools for designing materials for tunable white light-emitting devices.

Thermoluminescence studies of zinc borate (ZnB2 O4 ) phosphor doped with rare earths for dosimetric aspects.

A series of ZnB2 O4 phosphors doped with different concentrations of Eu and Dy (0.05 0.1, 0.2, 0.5, 1.0 mol%) and co-doped with Ce (1, 2, 5, 7, 10 mol%) respectively was prepared via the solid-state reaction technique and the thermoluminescence (TL) behaviour of gamma ray-irradiated samples was studied. The synthesized samples were irradiated with γ-rays for the dose range 0.03-1.20 kGy. The TL intensity variations with dose, dopant concentration, and the effect of co-doping were studied. The TL response curves for ZnB2 O4 :Eu3+ and ZnB2 O4 :Dy3+ , ZnB2 O4 :Eu3 ,Ce3+ and ZnB2 O4 :Dy3+ ,Ce3+ phosphor were observed. It was revealed that ZnB2 O4 :Eu3+ showed a linear TL behaviour for the dose 0.03-1.20 kGy and ZnB2 O4 :Dy3+ showed linearity for the gamma dose range 0.03-0.10 kGy. Furthermore, fading for all the samples was observed to be less than 10% for a storage period of 30 days. In addition to this, the trapping parameters, especially activation energies were evaluated using the Ilich method and the initial rise method. The activation energy values obtained from both methods were in complete agreement with each other.

Dynamics of the Ligand Excited States Relaxation in Novel ß-Diketonates of Non-Luminescent Trivalent Metal Ions.

Complexes emitting in the blue spectral region are attractive materials for developing white-colored light sources. Here, we report the luminescence properties of novel coordination compounds based on the trivalent group 3, 13 metals, and the 1-phenyl-3-methyl-4-cyclohexylcarbonyl-pyrazol-5-onate (QCH) ligand. [M(QCH)3] (M = Al, Ga, and In), [M(QCH)3(H2O)] (M = Sc, Gd, and Lu), [Lu(QCH)3(DMSO)], and [La(QCH)3(H2O)(EtOH)] complexes were synthesized and structurally characterized by a single-crystal X-ray diffraction study. It has been found that the luminescence quantum yields of the ligand increase by one order of magnitude upon metal coordination. A significant correspondence between the energies of the ligand's excited states and the luminescence quantum yields to the metal ion's atomic numbers was found using molecular spectroscopy techniques. The replacement of the central ion with the heavier one leads to a monotonic increase in singlet state energy, while the energy of the triplet state is similar for all the complexes. Time-resolved measurements allowed us to estimate the intersystem crossing (ISC) rate constants. It was shown that replacing the Al3+ ion with the heavier diamagnetic Ga3+ and In3+ ions decreased the ISC rate, while the replacement with the paramagnetic Gd3+ ion increased the ISC rate, which resulted in a remarkably bright and room-temperature phosphorescence of [Gd(QCH)3(H2O)].

Passive surveillance of wild fauna in northwestern Italy: a possible cognitive approach through geographical district study and fur elementary analysis.

The analysis of animal hair is a useful and non-invasive investigation method for monitoring metal content, whose beginning dates to a few decades ago. This study addresses the issue of wildlife mortality in Piedmont and Aosta Valley by linking the evidence to the characteristics of the territories and to hair elemental profile. The considered animal species were badger, fox, marten, and wolf. The quantitative data for 11 trace metals and 16 lanthanides were evaluated considering animal location and death causes regarding impacts, whose relevant number was confined to the Turin province and to the badger and fox species. The evaluation of the analytical results was performed after the out of bounds sample identification by mean of statistics. For trace metals, some areas have thus been identified, mainly in Turin province, in which the large excess of As, Cd, and Pb was related to district pollution. Moreover, the lower contents of Fe, Mn, and Al in Aosta Valley badgers' hair seem influenced by the different characteristics of the subsoil, in comparison to Piedmont, and a relationship with the living environment and the habits was suggested. Regarding lanthanides, Biella province represents an area in which environmental contamination and abundance of rare-earth elements was recorded.

Heavy and less common metals in rainwater and the kinetics of the oxidation of hydrogen sulfide by oxygen in rainwater medium.

As a sequel to our recent study on the oxidation by O2, i. e., autoxidation of dissolved hydrogen sulfide, H2S, in aqueous medium, we present here the results of a similar study in rain water medium. The rainwater sampling was done sequentially for four years (2016-2019). In all 67 samples of rainwater were collected on event basis during monsoon period (June-October) in and around the Campus of University of Rajasthan, Jaipur (26°50̛ N-75°52̛ E), which is situated in a semi-arid region adjacent to the Thar Desert in the North-Western part of the India having an annual average rainfall of 54 cm. ICP-MS technique was used in the analysis of rainwater and more than 30 metals were detected, which included transition metals, rare earths, less common metals. Beryllium, vanadium, silver, selenium, manganese, cerium, gallium, yttrium, barium, cesium, copper, rubidium, arsenic, lanthanum, cadmium, lead, uranium and bismuth were common to all rain water samples.H2S oxidation by dissolved oxygen was studied in rainwater as well as in laboratory water media for comparison. The kinetics rate law was: -d[O2]/dt = k1K1[H+][S][O2]t/( [H+]2 + K1[H+] + K1K2), where K1 is first dissociation constant of H2S and k1 is the rate constant for the dominant reaction step:HS- + O2 → products.

Novel Cerium-Based Sulfide Nano-Photocatalyst for Highly Efficient CO2 Reduction.

To address the environmental crisis caused by excessive emissions of CO2 , the development of effective photocatalysts for the conversion of CO2 into chemicals has emerged as one of the most promising strategies. Herein, beyond those well-studied materials, a rare-earth sulfide-based nanocrystal NaCeS2 is fabricated and investigated for efficient and selective conversion of CO2 into CO, where the role of Ce ions is crucial. Firstly, the hybridization of Ce 4f and Ce 5d orbitals contributes to the photoresponsive band structure of NaCeS2 . Secondly, due to the charge rearrangement supplied by the incompletely filled 4f orbitals of Ce ions, NaCeS2 exhibits excellent charge separation efficiency and CO2 adsorption affinity, reducing the energy barrier for the conversion from CO2 to CO. Moreover, a NaCeS2 -MoS2 heterostructure is also designed to further boost the electron transfer from the Mo site to the Ce site, which results in an improvement of the catalytic reduction yield from 7.24 to 23.42 µmol g-1 within 9 h (both better than TiO2 controls). This work offers a platform for the development of rare-earth-based photocatalysts for CO2 conversion.

Synthesis and Luminescence Properties of Amber Emitting La7 Sr[Si10 N19 O3 ] : Eu2+ and Syntheses of the Substitutional Variants RE8-x AEx [Si10 N20-x O2+x ] : Eu2+ with RE=La, Ce; AE=Ca, Sr, Ba; 0≤x≤2.

The oxonitridosilicate La7 Sr[Si10 N19 O3 ] : Eu2+ and its substitutional variants RE8-x AEx [Si10 N20-x O2+x ] : Eu2+ with RE=La, Ce; AE=Ca, Sr, Ba and 0≤x≤2 were synthesized starting from REN, SrN/Ca3 N2 /Ba2 N, SiO2 , amorphous Si3 N4 and Eu2 O3 as doping agent at 1600 °C in a radiofrequency furnace. The crystal structure of La7 Sr[Si10 N19 O3 ] was solved and refined based on single-crystal X-ray diffraction data. La7 Sr[Si10 N19 O3 ] crystallizes in the orthorhombic space group Pmn21 (no. 31). The crystal structures of the isotypic compounds RE8-x AEx [Si10 N20-x O2+x ] were confirmed by Rietveld refinements based on powder X-ray diffraction data using the single-crystal data of La7 Sr[Si10 N19 O3 ] as starting point. Crystal structure elucidation reveals a 3D network of vertex sharing SiN4 and SiN2 (N1/2-x/4 O1/2+x/4 )2 (0≤x≤2) tetrahedra. When excited with UV to blue light, La7 Sr[Si10 N19 O3 ] : Eu2+ shows amber luminescence with λem =612 nm and fwhm=84 nm/2194 cm-1 , which makes it interesting for application in amber phosphor-converted light emitting diodes.

Synthesis and photoluminescence enhancement of the LiLa(MoO4 )2 :Sm3+ red phosphors by co-doping with Bi3.

The LiLa(MoO4 )2 :Sm3+ and LiLa(MoO4 )2 :Sm3+ ,Bi3+ phosphors were prepared using the citric-acid-fueled combustion method and the influence of concentrations of Bi3+ dopant on LiLa(MoO4 )2 :Sm3+ red luminescence was investigated. The LiLa(MoO4 )2 :Sm3+ and LiLa(MoO4 )2 :Sm3+ ,Bi3+ samples matched well with the scheelite structure and I41 /a space group and did not detect structural changes. Under an excitation of 403 nm, the prepared LiLa(MoO4 )2 :Sm3+ ,Bi3+ phosphor was excited and produced orange-red emission. When compared with the LiLa(MoO4 )2 :Sm3+ phosphor, the LiLa(MoO4 )2 :Sm3+ ,Bi3+ phosphor exhibited enhanced fluorescence intensity because the Bi3+ dopant ions are doped as a sensitizer. The optimal doping concentrations of Sm3+ and Bi3+ were 5 and 1 mol%, respectively. Furthermore, the energy transfer from Bi3+ to Sm3+ is effective (3 P1 → 4 K11/2 ). Subsequently, the electrons in an unstable excited state were transferred to a stable ground state (4 G5/2 → 6 H5/2 , 6 H7/2 , 6 H9/2 ). The Commission Internationale de L'Eclairage (CIE) chromaticity coordinates of the optimized LiLa(MoO4 )2 :Sm3+ ,Bi3+ phosphor were situated in the orange-red region. The luminescence of the LiLa(MoO4 )2 :Sm3+ ,Bi3+ phosphor generated under near-ultraviolet (UV) irradiation could be used to produce a warm white light, indicating its possible applications in white light-emitting diodes.

Intensity of cooperative vibronic transitions in the Eu(III), Gd(III) and Tb(III) formates spectra.

The luminescence and absorption spectra of the lanthanide ions in solids and coordination compounds are characterized by sharp pure electronic lines, which are accompanied by much weaker lines of vibronic transitions. The vibronic spectroscopy is a good probing tool for investigations of the properties of surrounding ion ligands. The lanthanides formates are efficient luminescent crystals and can be viewed as the elementary type in the whole class of the oxygen-containing lanthanide coordination compounds. The intensity of vibronic transitions in spectra of luminescence and excitation europium (5 D0 →7 F2 , 7 F0 →5 D2 ), terbium (7 F6 →5 D4 ), gadolinium (6 P7/2 →8 S7/2 ) in anhydrous formates of the type Ln(HCOO)3 (Ln = Eu, Tb, Gd) and Y(HCOO)3 .2H2 O doped with Eu3+ and Tb3+ (C ~1 mol%) are reported. Also, the infrared and Raman spectra were obtained for the same compounds. Related integral intensity vibronic sidebands depend on the type of electronic transition of the same ion and varies for the same electronic transitions in different crystals. The obtained experimental data referring to the rate constants of vibronic transitions and intensity distribution in vibronic spectra on normal vibrations of the formate groups are in agreement with the predictions based on the Stavola-Dexter theory of cooperative vibronic transitions.