Synthesis,structures and near-infrared luminescence properties of Ho and Yb coordination complexes

Four Ln³⁺ coordination complexes with the formulas [Ln(p-toluylate)₂(Ac)(H₂O)]_n (Ln=Ho 1, Yb 2) and {[Ln₂(OOCCH₂CH₂COO)₃(H₂O)₄]·6H₂O}_n (Ln=Ho 3, Yb 4) were synthesized hydrothermally. Their structures were determined by single-crystal X-ray diffraction. Complexes 1 and 2 are isomorphic and form infinite 2D network structures comprising p-toluylate and acetate (Ac^–) moieties. Complexes 3 and 4 are also isomorphic and possess infinite 2D structures in which succinate acts as bridging ligands that are connected to a 3D hydrogen bonding network by O–H…O hydrogen bonds. Solid-state IR and UV-Vis-NIR spectra, excitation and emission spectra were determined for the four complexes at room temperature. Complexes 1 and 2 exhibit characteristic NIR emission bands of Ln³⁺ ions but these are shifted and split relative to the theoretical positions. This is also evident for their UV-Vis-NIR spectra. The influence of ligands on enhancing the NIR luminescence of Ln³⁺ ions in complexes is discussed.     

Syntheses, crystal structures, visible and near-IR luminescent properties of ternary lanthanide (Dy, Tm) complexes containing 4,4,4-trifluoro-1-phenyl-1,3-butanedione and 1,10-phenanthroline

The ligands 4,4,4-trifluoro-1-phenyl-1,3-butanedione (Hbfa) and 1,10-phenanthroline (phen) were used to prepare ternary lanthanide (Ln) complexes [Dy(bfa)₃phen and Tm(bfa)₃phen]. Crystal data: Dy(bfa)₃phen C₄₂H₂₆F₉N₂O₆Dy, triclinic, P1¯, a=9.9450(6) Å, b=14.0944(9) Å, c=14.6043(9) Å, α=82.104(1)°, β=87.006(1)°, γ=76.490(1)°, V=1971.1(2) Å³, Z=2; Tm(bfa)₃phen C₄₂H₂₆F₉N₂O₆Tm, triclinic, P1¯, a=9.898(5) Å, b=13.918(5) Å, c=14.753(5) Å, α=83.517(5)°, β=86.899(5)°, γ=76.818(5)°, V=1965.3(14) Å³, Z=2. The coordination number of the central Ln³⁺ (Ln=Dy, Tm) ion is eight, with six oxygen atoms from three Hbfa ligands and two nitrogen atoms from the phen ligand. The photophysical properties of the two complexes were studied by absorption spectra, diffuse reflectance spectra, and emission spectra. They show the characteristic luminescence of the corresponding Ln³⁺ ion in both visible and near-IR (NIR) region. Additionally, the energy transfer mechanisms between the ligands and central Ln³⁺ ions were discussed.     

Potential PDP phosphors with strong absorption around 172 nm: Rare earth doped NaLaP2O7 and NaGdP2O7

NaLaP₂O₇ and NaGdP₂O₇ powder samples are prepared by solid-state reactions at 750 and 600 °C, respectively, and the VUV-excited luminescence properties of Ln³⁺ (Ln=Ce, Pr, Tb, Tm, Eu) in both diphosphates are studied. Ln³⁺ ions in both hosts show analogous luminescence. For Ce³⁺-doped samples, the five Ce³⁺ 5d levels can be clearly identified. As for Pr³⁺ and Tb³⁺-doped samples, strong 4f-5d absorption band around 172 nm is observed, which matches well with Xe-He excimer in plasma display panel (PDP) devices. As a result, Pr³⁺ can be utilized as sensitizer to absorb 172 nm VUV photon and transfer energy to appropriate activators, and Tb³⁺-doped NaREP₂O₇(RE=La, Gd) are potential 172 nm excited green PDP phosphors. For Tm³⁺ and Eu³⁺-doped samples, the Tm³⁺-O²⁻ charge transfer band (CTB) is observed to be at 177 nm, but the CTB of Eu³⁺ is observed at abnormally low energy position, which might originate from multi-position of Eu³⁺ ions. The similarity in luminescence properties of Ln³⁺ in both hosts indicates certain structural resemblance of coordination environment of Ln³⁺ in the two sodium rare earth diphosphates.     

Radiationless Energy Transfer Between Rare-Earth Ions in Solutions and its Application to the Investigation of Complexation Processes

Radiationless energy transfer between rare-earth ions (Ln³⁺) in solutions has some features: 1) the electronic transitions in Ln³⁺ complexes causing the luminescence of energy donor and the absorption of energy acceptors are forbidden by Laporte's rule and are weakly intensive. Therefore the critical radius (R_o) of energy transfer between the rare-earth ions for dipole-dipole mechanism is close to that for exchange-resonant mechanism. This fact presents difficulties for unequivocal interpretation of the energy transfer mechanism. 2) The plus-three lanthanide ions exist in solution as a set of complexes with different number of charged ligands in the inner coordination sphere and hence with different total charge of complexes.     

Trapping mechanism in the afterglow process of the rare-earth activated Y2O2S phosphors

Phosphorescence properties are investigated in Y₂O₂S phosphors doped with rare-earth (lanthanoid, Ln) ions. Luminescence afterglow with a decay time of several ten milliseconds is observed at room temperature in the phosphors activated by Nd, Sm, Eu, Dy, Ho, Tm, Er, and Yb. The depths (thermal activation energies) of the traps causing the afterglow are measured with the transient luminescence method.It is concluded that the excited electron and the hole in the conduction and valence bands are trapped separately in the states (impurity levels) located in the vicinity of the Ln³⁺ ion. The trapping depths of the level range from 0.3 to 1.1 eV and are dependent on the electron affinity of the Ln³⁺ ion estimated from the energy difference between the 4fⁿ⁺¹ and the 4fⁿ configurations in the 4f shell of the ion.     

Energy transfer between lanthanide ions in nanostructures of their complexes. II

The changes in the luminescence intensity and in the luminescence lifetime of Eu, Tb, and Sm complexes with some β-diketones and 1,10-phenanthroline that occur upon formation of nanostructures with complexes of triply charged ions Pr, Nd, Sm, Eu, Dy, Ho, Er, Tm, and Yb—acceptors of the electronic excitation of luminescing ions—are compared for the first time. Pairs of lanthanide ions are suggested to exist inside nanostructures, which are bound by a bridge at a distance shorter (0.4 nm) in comparison with the size of interacting complexes. For a large number of pairs of donor and acceptor ions, the averaged probabilities (w _t) of energy transfer between these ions in nanostructures in the solution of each β-diketone under study are calculated. Based on the comparison of w _t with the predictions of the theory of the inductive resonance and exchange resonance energy transfer mechanisms, the average distance R between Ln(III) ions interacting in given fragments of nanostructures is estimated for each donor-acceptor pair, and the energy transfer mechanism is identified for the first time. It is shown that energy can be transferred between Ln(III) ions in nanostructures both according to the inductive resonance and via the exchange resonance mechanisms. The type of the transfer mechanism depends on the spectral parameters of interacting ions and on the ability of complexes of given acceptor ions to form heteronuclear nanostructures, whose composition determines the distance R. The variation in the value of R revealed for different ion pairs is explained by the occurrence of exchange resonance interactions between some ions. The overestimated probabilities w _t for ion pairs characterized precisely by exchange resonance interactions can be explained by the influence of covalent bonds in nanostructures of Ln chelates on π conjugation of overlapped electronic shells of interacting particles. By using the method of energy transfer between Ln(III) ions of complexes from distant spheres of a structure, the average minimal size of nanostructures formed is estimated to be 2.6–3.4 nm.     

Spectroscopic studies of lanthanide(III) ion complexes with diethyl(phthalimidomethyl) phosphonate

Complexation and photophysical properties of complexes of lanthanide ions, Ln(III), with diethyl(phthalimidomethyl)phosphonate ligand, DPIP, were studied. Interactions between Ln(III) and DPIP were investigated using Nd(III) absorption and Eu(III) and Tb(III) luminescence (emission and excitation) spectra, recorded in acetonitrile solution containing different counter ions (NO₃^-, Cl^- and ClO₄^-). Results of the absorption spectroscopy have shown that counter ions play a significant role in the complexation of Ln(III)/DPIP complexes. Studies of luminescence spectra of Eu(III) and Tb(III) ions proved that the formation of Ln(III)/DPIP complexes of stoichiometry Ln:L=1:3 is preferred in solution. Based on the results of elemental analysis, Nd(III) absorption spectra and IR and NMR data, it was shown that the DPIP ligand binds Ln(III) ions via oxygen from phosphoryl group, forming complexes of a general formula Ln(DPIP)₃(NO₃)₃·H₂O, in which the NO₃^- ions are coordinated with the metal ion as bidentate ligands. Luminescent properties and energy transfer, from the ligand to Ln(III) ions in the complexes formed, were studied based on the emission and excitation spectra of Eu(III) and Tb(III). Their luminescent lifetimes and emission quantum yields were also measured.     

Role of methylene spacer in the excitation energy transfer in europium 1- and 2- naphthylcarboxylates

A series of compounds Ln(RCOO)₃·Phen (Ln=Eu, Gd, Tb; RCOO⁻-1- and 2-naphthoate, 1- and 2-naphthylacetate, 1- and 2-naphthoxyacetate anions, Phen-1,10-phenanthroline) was investigated by methods of optical spectroscopy. Compounds of composition Ln(RCOO)₃·nH₂O with the same carboxylate ligands are also considered. Results of studies of the effects of methylene spacer decoupling the π-π- or p-π-conjugation in the naphthylcarboxylate ligand on the structure of Eu³⁺ coordination centre, on the lifetime of ⁵D₀ (Eu³⁺) state, and on processes of the excitation energy transfer to Eu³⁺ or Tb³⁺ ions are presented. Introduction of the methylene bridge in the ligand weakens the influence of the steric hindrances in forming of a crystal lattice and results in lowering the distortion of the Eu³⁺ luminescence centre, and in elongation of the observed ⁵D₀ lifetime τ_obs. The latter is caused by decrease in contribution of the radiative processes rate 1/τ_r. This is confirmed by the correlation between the lifetimes τ_obs and the quantities “τ_r·const” inversely proportional to the total integral intensities of Eu(RCOO)₃·Phen luminescence spectra. The methylene spacer performs a role of regulator of sensitization of the Ln³⁺ luminescence efficiency by means of an influence on mutual location of lowest triplet states of the ligands, the ligand-metal charge transfer (LMCT) states, and the emitting states of Ln³⁺ ions. The lowest triplet state in lanthanide naphthylcarboxylate adducts with Phen is related to carboxylate anion. A presence of the methylene spacer in naphthylcarboxylate ligand increases the triplet state energy. At the same time, the energy of “carboxylic group-Eu³⁺ ion” charge transfer states falls, which can promote the degradation of excitation energy. In naphthylcarboxylates investigated a range of the carboxylate triplet state energies from 19 150 to 20 600 cm⁻¹ was demonstrated in dependence on the type of the carboxylate anion. The interligand energy transfer from Phen to carboxylate lowest triplet state was revealed in complexes with Phen ligand. The effect of OH-group inserted in 1- or 3-position of 2-naphthoate ligand on the excitation energy transfer is also analyzed.     

Study of lanthanide liquid-crystalline complexes by Photoacoustic and luminescence spectroscopy

Lanthanide complexes Ln(bta)₃L₂ (Ln³⁺: Eu³⁺, Tb³⁺ and Ho³⁺; bta: benzoyltrifluoroacetonate; L: N-octadecyl-2-hydroxy-4-tetradecyloxybenzal- dimine) are synthesized. Their photoacoustic (PA) spectra are reported and interpreted. In the region of ligand absorption, PA intensity increases for Eu(bta)₃L₂, Tb(bta)₃L₂ and Ho(bta)₃L₂, respectively. It is found that the PA intensity of the ligand bears a relation to the intramolecular energy transfer process. By comparison with luminescence spectra, the energy transfer process and phase transition of lanthanide complexes are studied from two aspects: radiative and nonradiative processes.     

Efficient Sensitized Luminescence of Binuclear Ln(III) Complexes Based on a Chelating Bis-Carbacylamidophosphate

Binuclear rare earth complexes Ln₂L₃phen₂ (Ln^III?=?Nd^III, Sm^III, Eu^III, Tb^III, Dy^III, Yb^III and Y^III) with bis-CAPh type ligand - tetramethyl N,N′-(2,2,3,3,4,4-hexafluoro-1,5-dioxopentane-1,5-diyl)bis(phosphoramidate) (H₂L) and 1,10-phenanthroline (phen) were synthesized and characterized by elemental analysis, IR, NMR, absorption and luminescence spectroscopy. Luminescence measurements were performed for all the complexes in solid state and for the Eu^III, Tb^III and Y^III complexes - in solution in DMSO as well. The effective energy transfer from organic ligands to Ln^III ions strongly sensitizes the Ln^III ions emission and under excitation by UV light, the complexes exhibited bright characteristic emission of lanthanide metal centers. It was found that the energy level of the ligands lowest triplet state in the complexes matches better to resonance level of Eu^III rather than Tb^III ion. Depending on temperature the emission decay times of solid europium and terbium complexes were in the range of 1.5–2.0 ms. In solid state at room temperature the Eu^III complex possess intense luminescence with very high intrinsic quantum yield 91% and decay time equal 1.88 ms.

     

Laser spectroscopy of rare earth ions in lead borate glasses and transparent glass-ceramics

Rare earth doped lead borate glasses and transparent glass-ceramics have been studied using optical spectroscopy. Based on the absorption, emission and its decay and the Judd-Ofelt calculations, several radiative and laser parameters for Ln ³⁺ (Ln = Pr, Nd, Eu, Dy, Er, Tm) were evaluated. The large values of luminescence lifetime, quantum efficiency of excited state and room temperature peak stimulated emission cross-section suggest efficient laser transitions of Ln ³⁺ ions in lead borate glasses. The obtained results indicate that lead borate glasses and glass-ceramics containing Ln ³⁺ ions are promising host matrices for solid-state laser applications.     

Energy transfer and thermalization in LiYF4:Tm, Ho

Energy transfer processes are very important in solid-state laser systems because they can cause an enhancement of the luminescence emission resulting in a reduction of the laser threshold. In this work, a detailed investigation to understand the basic processes of energy transfer between Tm and Ho ions in LiYF₄, a solid-state laser crystal, was made. Data includes absorption, luminescence excitation and response to pulsed excitation. Dynamics of the energy transfer was analyzed by considering the kinetic evolution of the emissions of both ions. It was found that the energy transfer process between the ³ F ₄ spectral manifold of Tm and the ⁵ I ₇ spectral manifold of Ho results in thermal equilibration of these two manifolds. Received: 20 May 1999 / Revised version: 20 August 1999 / Published online: 27 January 2000     

Simultaneous observation of low temperature 4f-4f and 3d-3d emission spectra in a series of Cr(III)(ox)Ln(III) assembly

We report here the low temperature emission spectra in the heterometal dinuclear 3d-4f assembled molecular system [(acac)₂Cr^III(μ-ox)Ln^III(HBpz₃)₂] (Cr(ox)Ln:acac⁻=acetylacetonate, ox²⁻=oxalate, HBpz₃⁻=hydrotris(pyrazol-1-yl)borate; Ln=La, Nd, Ho, Er , Tm and Yb) in comparison with those of Na[Cr(acac)₂(ox)] and [(HBpz₃)₂Ln(μ-ox)Ln(HBpz₃)₂](Ln=Nd and Er). From 10 to 150 K the Cr(ox)Ln complexes show a broad emission band around 800 nm from the ²E state of Cr(III) moiety. At room temperature no ²E-⁴A₂ emission was observed in the Cr(ox)Ln except for the La and Lu complexes. On warming from 10 to 300 K rapid quenching of the ²E-⁴A₂ emission of Cr(III) is suggested to result from the energy transfer from Cr to Ln in the Cr(ox)Ln. The excitation spectra and the life-time were also measured with monitoring the 4f-4f emission peaks of the Cr(ox)Yb complex.     

A Mechanism of the influence of Gd(III) and other Ln(III) ions on sensitized luminescence of Eu(III) and Tb(III) ions in aqueous and ethanol solutions: The role of hydroxyl bridges

We studied sensitization of Eu(III) and Tb(III) ions by molecules of 1,10-phenanthroline and 2,2-bipyridil in D₂O and d ₆-ethanol and the influence of Nd(III), Pr(III), Sm(III), Gd(III), and Ho(III) ions on the luminescence intensity I _lum and lifetime τ_lum of Eu(III) and Tb(III) in solutions. The stability constants of complexes of Eu(III) and Gd(III) with 2,2′-bipyridil are measured by spectrophotometric and luminescence methods. It is shown that luminescence of Eu(III) is quenched by Gd(III) ions at the ion concentration equal to 10^?2–10^?1 M, which is caused by competing between these ions for a sensitizer. At the concentration of Ln(III) ions equal to 10^?6?10^?3 M, the sensitized luminescence of Eu(III) and Tb(III) was quenched and τ_lum decreased in the presence of Nd(III) ions, whereas in the presence of Gd(III) the luminescence intensity increased. It is proved that a bridge that connects the two ions upon energy transfer is formed by hydroxyl groups. The intensity of luminescence of Eu(III) and Tb(III) in aqueous solutions and its lifetime decreased in the presence of hydroxyl groups, while upon addition of Gd(III) to these solutions these quantities were restored. We also found that the addition of Gd(III) to deoxygenated ethanol solutions of 2,2′-bipyridil and Eu(III) slows down photochemical and thermal reactions between bipyridil and Eu(III), resulting in the increase in the luminescence intensity of Eu(III).     

Sensitized luminescence properties of dinuclear lanthanide macrocyclic complexes bearing a benzophenone antenna

Dinuclear lanthanide (Ln=Tb³⁺ or Eu³⁺) complexes (Ln₂L2) of two octadentate macrocyclic polyaminopolycarboxylic ligands connected through a benzophenone (BP) moiety (L2) have been synthesized. Sensitized luminescence properties of Ln₂L2 in water have been studied in comparison to those of BP-conjugated mononuclear Ln complexes (LnL1). The luminescence intensity of Tb₂L2 is lower than that of TbL1 because of lower triplet quantum yield of the BP moiety. In contrast, Eu₂L2 shows higher intensity than EuL1. For both Eu complexes, energy level of triplet excited-state BP (³BP*) is only 3 kJ mol⁻¹ higher than that of ⁵D₂ excited-state of Eu³⁺. The ⁵D₂ state formed by a triplet-energy transfer (TET) from ³BP* is therefore deactivated by a back energy transfer (BET) to the ground-state BP, resulting in low luminescence intensity of EuL1. In contrast, within Eu₂L2, TET from ³BP* to ⁵D₀ state of two Eu³⁺ ions is accelerated, thus leading to higher luminescence intensity. Another notable feature of Eu₂L2 is the luminescence quantum yield independent of its concentration. In contrast, for EuL1 system, an intermolecular BET occurs from ⁵D₂ state of Eu³⁺ to the ground-state BP conjugated to another EuL1 complex, resulting in a yield decrease with the concentration increase.     

Energy transfer phenomena in ordered perovskites of the type Sr2Na0.5Ln3+0.5X6+O6

We have investigated perovskites with composition Sr₂Na_0.5Ln³⁺_0.5WO₆ and Sr₂Na_0.5Ln³⁺_0.5 UO₆ (Ln = La, Gd, Eu). Their luminescence gives information on crystallographic details of the crystal structure and on a number of different energy transfer phenomena in these compounds. For Ln = La the Na⁺ and La³⁺ ions are disordered; for Ln = Gd(Eu) they are ordered. Single-step energy transfer is observed for the couples U⁶⁺ -Eu³⁺ and W⁶⁺ - Eu³⁺; energy migration occurs within the uranium and the europium sublattices.     

Investigation of up-conversion luminescence properties of RE/Yb co-doped Y2O3 transparent ceramic (RE=Er, Ho, Pr, and Tm)

RE/Yb co-doped Y₂O₃ transparent ceramics (RE=Er, Ho, Pr, Tm) were fabricated and characterized from the point of up-conversion luminescence. All the samples exhibit high transparence not only in near-infrared band (NIR) band but also in visible region, which ensures the output of the up-conversion luminescence. Under 980 nm excitation, green and red emissions were observed in Er, Yb:Y₂O₃ transparent ceramic, while green emission was detected in Ho, Yb and Pr, Yb co-doped Y₂O₃ transparent ceramics. In Tm, Yb co-doped Y₂O₃ ceramic, very intense blue up-conversion luminescence was detected. The dependence of up-conversion emission intensity on the pumping power was measured for each RE/Yb co-doped Y₂O₃ transparent ceramic, and the up-conversion mechanism was discussed in detail. Meanwhile, the energy transfer efficiency was calculated.     

Thermally stimulated luminescence of Ca3(PO4)2 and Ca9Ln(PO4)7 (Ln = Pr,Eu, Tb,Dy, Ho,Er, Lu)

The series of whitlockite compounds Ca₃(PO₄)₂ and Ca₉Ln(PO₄)₇ (Ln = Pr, Eu, Tb, Dy, Ho, Er, Lu) was studied in radioluminescence (RL) and thermally stimulated luminescence (TSL) excited by X-rays. f-f emission lines of Ln³⁺ were observed in RL for Ca₉Ln(PO₄)₇ (Ln = Pr, Eu, Tb, Dy, Ho, Er) whereas d-d emission band of the impurity Mn²⁺ was observed in Mn:Ca₃(PO₄)₂ and Mn:Ca₉Lu(PO₄)₇ at 655 nm. In TSL, the Eu, Ho and Er compounds did not show any signal. As Eu³⁺, Ho³⁺ and Er³⁺ present the highest Ln³⁺/Ln⁴⁺ ionization potential (IP) of the series, this was interpreted as the inability of these lanthanides to trap a hole. On the contrary Pr³⁺ in Ca₉Pr(PO₄)₇, Tb³⁺ in Ca₉Tb(PO₄)₇, Dy³⁺ in Ca₉Dy(PO₄)₇, Mn²⁺ in Mn:Ca₃(PO₄)₂ and Mn:Ca₉Lu(PO₄)₇ were identified as hole traps and radiative recombination centers in the TSL mechanism. Ca₉Tb(PO₄)₇ was found to be a high intensity green persistent phosphor whereas Mn:Ca₉Lu(PO₄)₇ is a red persistent phosphor suitable for in vivo imaging application.     

Luminescence properties of Y2O3:Bi3+, Ln3+ (Ln=Sm,Eu, Dy,Er, Ho) and the sensitization of Ln3+ by Bi3+

The spectroscopic characterization of yttria, singly and doubly doped with Ln³⁺ (Ln=Sm, Eu, Dy, Er, Ho) and Bi³⁺ ions, is performed through excitation spectra, emission spectra and decay time measurements. The obtained spectroscopic data clearly indicate that energy transfer takes place from Bi³⁺ to Ln³⁺ ions. The energy transfer efficiency of Bi³⁺→Ln³⁺ and quantum efficiency of Ln³⁺ were calculated. Upon excitation of 370 nm (Bi³⁺ excitation band), the quantum efficiency of Ln³⁺ varies from ～4% to ～44%. The energy transfer efficiency increases continuously with increasing Ln³⁺ concentrations, whereas the variation of the quantum efficiency of Ln³⁺ is complicated. The quantum efficiency of Ln³⁺ is discussed in terms of electron transfer and cross relaxation.     

Energy transfer from Eu(III) and Tb(III) complexes to dyes in their mixed nanostructures. I

The formation of nanostructures that consist of complexes of β-diketones with 1,10-phenanthroline and involve dyes of the polymethine, triphenylmethane, oxazine, and xanthene series is observed in aqueous solutions. It is found that nanostructures of complexes of Ln(III) ions and dyes are reliably observed at concentrations of Ln complexes from 0.5 to 5 μM and at dye concentrations above 5 nM. Nanostructures of complexes Eu(MBTA)₃phen, Eu(NTA)₃phen, Eu(PTA)₃phen, Tb(PTA)₃phen, Gd(MBTA)₃phen, and Lu(MBTA)₃phen with dyes are studied, where MBTA is n-methoxybenzoyltrifluoroacetone, NTA is naphthoyltrifluoroacetone, PTA is pivaloyltrifluoroacetone, and phen is 1,10-phenanthroline. It is shown that nanostructures formed can contain dye molecules not only inside a nanostructure of Ln complexes but also on its outer shell. It is proved that, at a dye concentration in the solution of the order of nanomole or higher, the formation of mixed nanostructures of Eu complexes and dyes whose S ₁ level is below the ⁵ D ₀ level of Eu(III) leads to the quenching of the luminescence of Eu(III) and gives rise to the sensitized luminescence of dyes. The energy transfer efficiency from Eu(III) ions to dye molecules is determined by the ability of these molecules to incorporate into nanostructures of Eu complexes. The effect of the formation of nanostructures on the shape and position of the spectra of luminescence and absorption of dyes is studied. Comparison of the sensitized luminescence intensities of Nile blue in structures of Eu, Lu, and Gd complexes shows that the greater part of the excitation energy of Eu complexes is transferred directly from ions to dye molecules according to the inductive-resonance energy transfer mechanism rather than by means of energy migration over singlet levels of organic ligands in complexes of a nanostructure.