Transitions Of Europium Research Articles

Potential of Y2Sn2O7:Eu3+, Dy3+ Inorganic Nanophosphors in Latent Fingermark Detection

In this work, we investigated the potential of Eu3+/Dy3+-codoped Y2Sn2O7 fluorescent nanophosphors to visualize latent fingermarks. We prepared these nanophosphors with various doping concentrations by the conventional coprecipitation reaction. The crystal structure, morphology, luminescence properties, and energy transfer mechanisms were studied. The crystalline phase was characterized by X-ray diffraction and crystal structure refinement using the Rietveld method. XRD measurements showed that the samples crystallized in the pure single pyrochlore phase with few more peaks originated from secondary phases and impurities generated during phosphor production, and that Eu3+ ions occupied D3d symmetry sites. The average crystallite size after mechanical grinding was less than 100 nm for all compositions. The optical characterization showed that, when excited under 532 nm, the Eu3+/Dy3+-codoped Y2Sn2O7 samples’ main intense emission peaks were located at 580–707 nm, corresponding to the 5D0→7Fj (j = l, 2, 3, and 4) transitions of europium. In fact, the 5D0→7F2 hypersensitive transition is strongly dependent on the local environment and was quite weak in Eu3+:Y2Sn2O7 at low Eu3+ doping levels. We found that the presence of Dy3+ as a codopant permitted enhancing the emission from this transition. The calculated PL CIE coordinates for the synthesized nanophosphors were very close to those of the reddish-orange region and only slightly dependent on the doping level. Various surfaces, including difficult ones (wood and ceramic), were successfully tested for latent fingerprint development with the prepared Eu3+/Dy3+-codoped Y2Sn2O7 fluorescent nanophosphor powder. Thanks to the high contrast obtained, fingerprint ridge patterns at all three levels were highlighted: core (level 1) islands, bifurcation, and enclosure (level 2), and even sweat pores (level 3).

Photophysical characteristics of Eu(III) 1,3-diketonates with substituted 1,10-phenanthroline auxiliary moieties: Experimental and theoretical approach

A fluorinated β-diketone ligand 4,4,4-trifluoro-1-(2-furyl)-1,3-butanedione (TFFB was utilized as main sensitizer for preparing a series of luminescent Eu(TFFB)3X [X= auxiliary moiety] complexes. The 1H NMR spectra were found to be in accordance with the formation of 8 coordinated mononuclear complexes. Theoretically determined probability amplitude distributions have also supported the structural environment around Eu(III) cation as estimated from spectroscopic studies. In the absorption patterns, broad band corresponding to absorption by chromophoric units was observed. Upon UV excitation, emission patterns of complexes evince sharp peaks ascribed to transitions of europium(III) cation. The photophysical characteristics viz., energy level diagram, the radiative lifetimes (τ), and Judd-Ofelt (JO) intensity parameters of complexes were calculated. The complexes might be employed as a promising emissive material while creating displays.

Clamping effect on temperature-induced valence transition in epitaxial EuPd2Si2 thin films grown on MgO(001)

Bulk ${\mathrm{EuPd}}_{2}{\mathrm{Si}}_{2}$ show a temperature-driven valence transition of europium from $\ensuremath{\sim}+2$ above 200 K to $\ensuremath{\sim}+3$ below 100 K, which is correlated with a shrinking by approximately 2% of the tetragonal crystal lattice along the two $a$-axes. Due to this interconnection between lattice and electronic degrees of freedom the influence of strain in epitaxial thin films is particularly interesting. Ambient x-ray diffraction (XRD) confirms an epitaxial relationship of tetragonal ${\mathrm{EuPd}}_{2}{\mathrm{Si}}_{2}$ on MgO(001) with an out-of plane $c$-axis orientation for the thin film, whereby the $a$-axes of both lattices align. XRD at low temperatures reveals a strong coupling of the thin film lattice to the substrate, showing no abrupt compression over the temperature range from 300 to 10 K. Hard x-ray photoelectron spectroscopy at 300 and 20 K reveals a temperature-independent valence of $+2.0$ for Eu. The evolving biaxial tensile strain upon cooling is suggested to suppress the valence transition. Instead temperature-dependent transport measurements of the resistivity and the Hall effect in a magnetic field up to 5 T point to a film thickness independent phase transition at 16 to 20 K, indicating magnetic ordering.

New europium-doped carbon nanoparticles showing long-lifetime photoluminescence: Synthesis, characterization and application to the determination of tetracycline in waters

The growing appearance of antibiotic-resistant strains of microorganisms originated from the widespread use and ubiquitous presence of such drugs is a major concern in the world. The development of methodologies able to detect such substances at low concentration in real water samples is mandatory to overcome this problem. Europium(III) is known to form complexes with tetracycline (TC) with photoluminescent characteristics useful for TC determination.In the present work, we synthesized for the first time carbon nanoparticles (CN) showing delayed photoluminescence using a Europium(III) doping synthesis. The new material (PCNEu) was characterized both morphologically and spectroscopically, showing an analytical photoluminescent signal in presence of TC, arising from the 5D0→7F2 transition of europium, one hundred times higher than that of the europium salt alone in presence of the antibiotic. This enhancement is a consequence of the amplifying effect exerted by nanoparticle structure itself, leading to an efficient synergistic “antenna effect” in the system PCNEu - TC. The analytical signal is affected both by pH and the nature of the buffer used, and it allows the detection of tetracycline in waters with a limit of detection of 2.18 nM and recoveries between 90 and 110%. The analytical performance of the developed methodology enables having lower limits of detection than other luminescent and chemiluminescent reported methodologies.

Experimental evaluation of the luminescence performance of fired clay brick coated with SrAl2O4:Eu/Dy phosphor

This study evaluates the luminescence performance of fired clay bricks coated with SrAl2O4:Eu/Dy phosphor. To do so, SrAl2O4:Eu/Dy phosphor was first produced using the traditional solid-state reaction synthesis technique. The prepared phosphor was then used for coating fired clay bricks to analyze the luminescence performance via spectral analysis, decay characteristics, and microstructure of the bricks. The results reveal that excitation and emission spectra of the phosphor coated bricks range from 200 to 480 nm and 455 to 650 nm, respectively, suggesting that the phosphor coated bricks have the capacity of absorbing light with a wide range of wavelengths. The peak wavelength projected at 511 nm in the emission spectrum is achieved, which indicates 4f65 d1-4f7 transition of Europium (Eu2+). The repeated excitation and deexcitation of Eu2+ by using hole traps and trap levels offered by Dysprosium (Dy3+), exist between the ground and the excited state of Eu2+ leads to luminescent phenomenon. Moreover, the decay characteristics has revealed that phosphor coated bricks can emit light for a considerable amount of time (>8.5 min) upon the removal of the excitation source. The results reveal that phosphor coated bricks has the potential of increasing energy efficiency of residential and commercial buildings.

Effect of Lipophilicity in Oxyanion‐Responsive Europium(III) Complexes**

AbstractResponsive lanthanide(III) complexes – europium(III) complexes in particular – have been the focus of studies for several decades. While responsive lanthanide complexes have been reported and investigated frequently, the supramolecular aspects and linear free‐energy relationship have seen less attention. Here, we are revisiting five europium(III) complexes and investigating their binding to ten different guests, all with a primary interaction between the europium(III) ion and a bidentate carboxylate anion. The studies consisted of measuring emission spectra, analysing band behaviours of the europium transitions, and calculating lifetime isotherms. The media effect was also investigated, and by eliminating the impact of hydrophobic effects, we can show that selectivity in these host‐guest systems can be tuned by the secondary lipophilic interactions.

Polarized spectroscopy of electric and magnetic dipole transitions of Europium (III) ions in C2 sites

Polarization anisotropy of luminescent properties of europium (III) ions in low-symmetry C2 sites is studied using monoclinic (sp. gr. C2/c) tungstate crystal KY(WO4)2. The 5D0 → 7FJ (where J = 0…6) transitions are characterized for the principal light polarizations. Polarization selection rules for the magnetic dipole 5D0 → 7F1 transition are presented. The stimulated-emission cross-sections for Eu3+ ions relevant for laser operation are determined.

Design, Synthesis, Crystal Structure and Photoluminescence Properties of Four New Europium (III) Complexes with Fluorinated β-Diketone Ligand

The strong photoluminescence properties of europium complexes with organic ligands attracted the attention of many researchers and found a wide range of uses in medical, industrial and biological fields. In this article, four new Tetrakis europium complexes 3a, 3b, 3c and 3d have been prepared using 1-phenyl-4,4,4-trifluoro-1,3-butenedionato ligand and pyridinium, bipyridinium, piperazinium and piperidinium counter cations. These complexes have been characterized by negative FAB-mass. The crystal structures of 3a, 3b, 3c and 3d were determined by single crystal X-ray diffraction analysis. The complex 3a crystallized in monoclinic form, space group P21/n with four molecules in the unit cell. The complex 3b crystallized in monoclinic form, space group P2/n with two complex molecules in the unit cell. The complex 3c crystallized in monoclinic form, space group C2/c with sixteen molecules in the unit cell. The complex 3d crystallized in monoclinic form, space group P21/n with four complex molecules in the unit cell. The complex 3a has 1,2-alternative structure, 3b has 1,3-alternative structure, 3c has cone like structure and 3d has partial cone like structure. The photoluminescence properties of these complexes have been evaluated. Strong red emissions were observed in all four complexes due to 5D0 → 7F2 transition of Europium (III) ions under UV excitation. Four β-diketone ligands acted as strong antenna ligands and transferred the absorbed energy to europium (III) ion effectively; consequently strong red luminescence was observed.

Synthesis and characterization of a novel Europium(III) complex with a one-dimensional chain-like structure

By means of a solvothermal reaction of isonicotinic acid and europium perchlorate, a novel europium(III) complex, i.e. catena-[tri(μ2-isonicotinato-O,O′)-(biaqua-europium(III))-(triperchlorate)-(monohydrate)], [Eu(HIA)3(H2O)2]n·3n(ClO4)·nH2O (1; HIA ​= ​isonicotinic acid), was obtained. The molecular structure of complex 1 was characterized by single-crystal X-ray crystallography. Complex 1 crystallized in the space group Pī of the triclinic system with a ​= ​9.5500(2), b ​= ​10.9680(3), c ​= ​15.1214(4) Å, α = 104.299(2)°, β = 91.532(2)°, γ = 111.310(2)°, V ​= ​1417.92(6) Å3, C18H21Cl3EuN3O21, Mr ​= ​873.69, Z ​= ​2, Dc ​= ​2.046 ​g/cm3, μ(MoKα) ​= ​2.595 ​mm−1 and F(000) ​= ​864. The europium(III)) ions are coordinated by eight oxygen atoms (of which six come from six HIA ligands and two come from two water molecules) and displays a EuO8 square antiprismatic geometry. The adjacent europium(III) ions are interlinked by four or two μ2-bridging HIA ligands to generate an infinite one-dimensional (1-D) –Eu–(HIA)4–Eu–(HIA)2–Eu–(HIA)4–Eu– chain running along the a axis. The chains are further connected by π···π stacking and hydrogen bonding interactions to yield a three-dimensional (3-D) supramolecular network. Complex 1 exhibits red photoluminescence emission bands at 593 ​nm, 617 ​nm and 699 ​nm, which are originated from the 5D0 → 7F1, 5D0 → 7F2 and 5D0 → 7F4 characteristic transitions of europium(III) ions. It has CIE chromaticity coordinates of (0.5742, 0.3275). A solid-state UV/Vis diffuse reflection spectrum shows that complex 1 has a band gap of 5.02 ​eV with a direct transition process.

Why Do Relative Intensities of Charge Transfer and Intra-4f Transitions of Eu3+ Ion Invert in Yttrium Germanate Hosts? Unravelling the Underlying Intricacies from Experimental and Theoretical Investigations.

The dominant intensity of parity-forbidden intra-4f transitions of europium(III) over O → Eu charge-transfer band (CTB) intensity is against common perceptions, yet this trend is observed in many germanate hosts and has not been rationalized so far. In search of a plausible explanation for this unusual trend, present work reports an experimental and theoretical investigations in conjunction on two sibling germanate host, namely, Y2GeO5 and Y2Ge2O7 having dopant Eu3+ in their respective YO7 polyhedra. Whereas for Y2GeO5:Eu3+, the CTB is more intense than the intra-4f transitions in the excitation spectrum, in the case of Y2Ge2O7:Eu3+, the relative intensities of CTB and intra-4f transitions are reversed. Comparative structural analysis reveals that Eu3+ present in YO7 of Y2GeO5 has a greater number of tetra-coordinated oxygen (Otetra) and yttrium atom as first and second neighbors, respectively (Eu3+-Otetra-Y3+ linkages). Conversely, in Y2Ge2O7 host, the Eu3+ ion mostly has tricoordinated oxygen (Otri) as its nearest neighbor and germanium ions next to Otri (Eu3+-Otri-Ge4+ linkage). Theoretical calculations reveal that while Y2GeO5:Eu has Otetra(4Y) dominating at the Fermi level and the 4f state of Eu3+ remains inert toward mixing, in Y2Ge2O7:Eu, the Fermi level has major contribution from Otri(2Y + 1Ge) with significant mixing with 4f states of Eu. The dominant control of Eu3+-Otri-Ge4+ linkages in geometrical and electronic structure of Y2Ge2O7:Eu owing to the GeO4 surrounding has been attributed to relative poor intensity of O → Eu CTB. Siege of Eu3+ by GeO4 and subsequent occurrence of Eu3+-Otri-Ge4+ linkages play a dual role: First, it induces electronic rigidity to hinder excitation of electron at bridging (Otri) oxygen by highly charged small Ge4+ cation; second, the covalent character in Eu-O bond is achieved by intermixing of Eu's 4f and Otri 2p orbital which facilitates relaxing of the parity-selection rule thus enhancing the probability of intra-4f transitions. The inferences drawn remain valid when extrapolated to other inorganic oxides having EuOx polyhedra surrounded by covalent units like PO4, SiO4, etc. and have a prevailing number of low-coordinated oxygen atoms and highly charged small cation in the first and second coordination shells, respectively. The optical basicity concept is also found to endorse our explanation. These remarkable generic inferences will pave the rational way for designing efficient phosphors for solid-state lighting.

Red luminescence and UV light generation of europium doped zinc oxide thin films for optoelectronic applications

In the present work, the Europium doped Zinc Oxide (ZnO: Eu) thin films were elaborated using spray pyrolysis technique. We are interested in investigating the structural properties, photoluminescence (PL) and third harmonic generation (THG) of the elaborated films. The structural properties of as-prepared thin films were characterized by X-ray diffraction (XRD). It confirms that all deposited thin films of Europium doped Zinc Oxide are crystallized in the hexagonal wurtzite structure. Both undoped and doped europium thin films show strong preferred c-axis orientation. Photoluminescence (PL) emission from Europium doped Zinc Oxide thin films, under excitation by 266 nm, shows characteristic transitions of Europium (5D0 → 7F0, 5D0 → 7F1, 5D0 → 7F2, etc.). It reveals the good incorporation of Eu3+ ions in the ZnO host. Additionally, the 5D0 → 7F2 is the most intense transition usually observed for Eu3+ embedded in materials of Zinc Oxide lattice. The dependence of third-order nonlinear susceptibility on doping rate was evaluated. The highest nonlinear susceptibility χ 3 is obtained for the 5% Europium doped ZnO sample.

Low-temperature solid-state synthesis and luminescent performance of a novel Li2NaBP2O8-based phosphor activated with europium (III)

For the application of inorganic phosphors in solid-state lighting field, exploring a synthesis route with low energy consumption and low cost is the current research focus. In this study, a low-temperature solid-state synthesis route for a novel Li2NaBP2O8:Eu3+ (LNBP:Eu) phosphor is reported. The phase structure, morphology, and elemental composition of its powder phase are characterized. According to photoluminescence and X-ray photoelectron spectroscopy data, the occupancy site and oxidation state of doping europium are discussed. Under near-UV (395 nm) excitation, the powder phase exhibits reddish-orange emission with a dominant 5D0 → 7F1 transition of europium. The intensity of visible photoluminescence is closely influenced by the europium doping content. The optimal content is 0.04 mol, and concentration quenching is ascribed to energy transfer among the nearest-neighbor europium ions. Moreover, chromatic properties are investigated in detail. The obtained data show that the LNBP:Eu powder phase is a prospective phosphor for application in near-UV-converted warm white light-emitting diodes.

Spectroscopic peculiarities of excitation and emission processes as well as relaxation dynamic of excited states in doubly and triply doped Gd3Ga3Al2O12:Ln3+ (Ln3+=Eu3+, Tb3+, Ce3+) crystals

Spectroscopic properties of Gd3Ga3Al2O12 (GGAG) single crystals co-doped with various configurations of (Eu + Tb); (Eu + Ce); (Tb + Ce) and (Eu+ Tb + Ce) ions have been investigated. The effect of distinct Ln3+ co-doping variations on luminescence of garnet crystals was studied using the different excitation wavelengths. The Ln3+-Ln3+ and host-Ln3+ interplays have been considered in doubly and triply doped GGAG:Ln3+. The crystals containing cerium ions are characterized by mainly broadband emission in the 450–750 nm spectral region that is adequately modified in green and red spectral range in the samples co-doped with terbium and europium, respectively. The Eu3+ luminescence in materials under study is selectively excited employing solely f-f europium transitions. Contrary to that, emission of terbium and cerium occur as result of interaction with Gd3+ and adjacent co-dopants.

Synthesis of Multifunctional Fe3O4@TESPA/Eu(NTA)3 Luminescent–Magnetic Nanoparticle and Their Properties

Novel multifunctional Fe3O4@3-(triethoxysilyl)-propylamine (TESPA)/Eu(NTA)3 luminescent–magnetic nanoparticles have been successfully prepared using a modified Stober method. The multifunctional nanoparticles are composed of super-paramagnetic Fe3O4 nanoparticles coated with a surface functional layer (SFL) of TESPA. The SFL is doped with a strong luminescent europium(III) complex with organic ligands 1-(2-naphthoyl)-3,3,3-trifluoroacetone (NTA) (Eu(NTA)3). The obtained Fe3O4@TESPA/Eu(NTA)3 nanoparticles exhibit a high magnetization and red emission with ${^{5}\text{D}_{0}}\to {^{7}}\text{Fn}$ ( $n = 1$ , 2, 3, and 4) transitions of europium(III) ion. These multifunctional luminescent–magnetic nanoparticles show small size, high stability, and excellent dispersity in aqueous solution that suggests promising applications in imaging diagnostic and cancer therapy.

Synthesis, photoluminescence and theoretical explanations of trivalent europium-doped lithium nitrate crystal

Novel red emitting europium-doped lithium nitrate were prepared by using the solid-state reaction, and characterized by the X-ray diffraction and photoluminescence techniques. The characteristic main emission bands from 5D0 to 7F1 (594nm, yellow) and to 7F2 (615, 625nm, red) transitions of trivalent europium were observed in the emission spectra of europium-doped lithium nitrate while excited by the near-ultraviolet light (394nm). The effects of the europium concentration in europium-doped lithium nitrate phosphors on the photoluminescence were investigated in detail. The results showed that the relative photoluminescence intensity increases with europium-concentration increasing until a maximum intensity is reached, and then it decreases due to concentration quenching, which are explained satisfactorily with the luminescent theory. The optimum concentration (∼0.07M) of europium in lithium nitrate is obtained. The f-f transitions of europium in lithium nitrate are calculated by diagonalization crystal-field energy matrix of 4f6 ion, and the optical spectra of europium-doped lithium nitrate are explained satisfactorily. The results are discussed.

Relative Study of Luminescent Properties with Judd-Ofelt Characterization in Trivalent Europium Complexes Comprising ethyl-(4-fluorobenzoyl) Acetate

Five new europium(III) complexes Eu(p-EFBA)3.(H2O)2 (C1), Eu(p-EFBA)3.neo (C2), Eu(p-EFBA)3.batho (C3), Eu(p-EFBA)3.phen (C4), Eu(p-EFBA)3.bipy (C5) have been synthesized by using ethyl-(4-fluorobenzoyl) acetate (p-EFBA) as β-ketoester ligand and neocuproine (neo), bathophenanthroline (batho), 1,10-phenanthroline (phen) and 2,2-bipyridyl (bipy) as ancillary ligands. The synthesized complexes C1-C5 were characterized by elemental analysis, nuclear magnetic resonance spectroscopy (1H-NMR), infrared (IR) spectroscopy, thermogravimetric analysis (TG/DTG), UV-visible and photoluminescence (PL) spectroscopy. The relative study of luminescence spectra of complexes with the previously reported complexes of isomeric ligand (ortho and meta substituted ligand) indicate the higher luminescence properties of complexes as an effect of fluorine position on β-ketoester ligand. The para substituted ligand shows a remarkable effect on quantum efficiencies and Judd-Ofelt intensity parameters (Ω2, Ω4) of the complexes. The higher value of intensity parameter Ω2 associated with hypersensitive 5D0→7F2 transition of europium(III) ion revealing highly polarizable ligand field. The purposed energy transfer mechanism of complexes indicates the efficient energy transfer in complexes.

Hyperfine structure studies of neutral europium transitions at 601.815 and 580.027 nm by saturation absorption spectroscopy.

We report Doppler-free spectroscopy of neutral europium carried out using the saturation absorption technique. In the present experiment, Eu/Ne hollow cathode discharge is used as an atomic vapor source of europium. The Eu transition 4f76s2(S87/2°)→4f76s6p(P89/2) at 601.815 nm and 4f75d6s(aD1013/2°)→4f75d6p(zD811/2) at 580.027 nm are investigated. The frequency separation between the adjacent hyperfine transitions as well as hyperfine structure (HFS) constants are calculated from the obtained experimental spectra. The HFS constant obtained for the state 4f76s6p(P89/2) are A151=664.8 MHz; B151=293.5 MHz, and for state 4f75d6p(zD811/2), the values are A151=7.6 MHz; B151=-60 MHz. These obtained values are in good agreement with the results reported in the literature using laser induced atomic beam fluorescence technique.

Syntheses, Crystal Structure and Photoluminescence Properties of Piperidinium Tetrakis (1,3-Diphenyl-1,3-Propanedionato) Europate(III) Complex and Its Two Different Crystals

Treatment of 1,3-diphenyl-1,3-propanedione 1a with europium (III) chloride in the presence of piperidine results in the halide ligands exchange giving newly piperidinium tetrakis (1,3-diphenyl-1,3-propanedionato)europate(III) complex 2a. The complex was characterized by 1H-NMR, positive FAB-mass, and Elemental Analysis. The exact molecular structure of 2a was determined by single crystal X-ray diffraction with the monoclinic space group Cc (centrosymmetric, No.13). The large cavity sizes of the complex 2a facilitated the inclusion of water and benzene solvate molecules. The other two different crystals 2b, 2c having two water molecules and one benzene moleculewere obtained by the crystallization in different solvents and the exact molecular structures were determined by single crystal X-ray diffraction analysis with space groups P21/n (centrosymmetric, No.14), and P21/n (centrosymmetric, No.14), respectively. The eight coordinate structures of the complexes in the three crystals were slightly different due to the crystal packing and the existence of the solvent molecule(s). The photoluminescence studies indicated that four β-diketone ligands acted as strong antenna ligands and transferred the absorbed energy to europium (III) ion, consequently red luminescence was observed. These strong emissions wereattributed to the 5D0 → 7F2 transition of Europium (III) ions under UV excitation. The photoluminescence spectrum of the three crystals was almost same in solid as well as in solution.

Optical characteristics of Eu(III) doped MSiO3 (M = Mg, Ca, Sr and Ba) nanomaterials for white light emitting applications

A series of Eu(III) doped MSiO3 (M = Mg, Ca, Sr and Ba) nanomaterials of high color purity were prepared using sol–gel technique at 950 °C. Samples were further reheated at 1050 and 1150 °C for 1 h in muffle furnace to study the effect of temperature on the structural aspects and optical characteristic of prepared materials. X-ray diffraction study was used to know the crystal structure of synthesized silicate phosphors. All the prepared materials existed in the single phase and dopant ion have no influence on the crystal structure of host materials. Under 395 nm excitation, photoluminescence emission spectra of silicate materials showed the characteristic red emission in 610–615 nm region due to the electric dipole (5D0 → 7F2) transition of europium(III) ion. Color coordinate values of these materials were located in the red region of Commission Internationale de I’Eclairage triangle. Fourier transform infra red spectroscopic studies were used to know the structure and bonding present in these phosphors. Transmission electron microscopic confirmed that the particle size of prepared nanomaterials exist in the nano range. The results suggested that these red emitting phosphors could be useful for generation of white-light emitting diode applications.

Synthesis, photoluminescence features with intramolecular energy transfer and Judd–Ofelt analysis of highly efficient europium(III) complexes

The luminescent binary and ternary europium(III) complexes were prepared by employing ethyl-(3-fluorobenzoyl) acetate (m-EFBA) as primary ligand and neocuproine (neo), bathophenanthroline (batho), 1,10-phenanthroline (phen) and 2,2-bipyridyl (bipy) as secondary ligands. The synthesized complexes Eu(m-EFBA)3·(H2O)2 (C1), Eu(m-EFBA)3·neo (C2), Eu(m-EFBA)3·batho (C3), Eu(m-EFBA)3·phen (C4), Eu(m-EFBA)3·bipy (C5) were characterized by the means of elemental analysis (C, H and N), nuclear magnetic resonance spectroscopy (1H-NMR), infrared spectroscopy (IR), thermogravimetric analysis (TG/DTG), UV–visible and photoluminescence (PL) spectroscopy. The photoluminescence spectra of complexes exhibit the characteristic emission band at 613 nm assigned to hypersensitive 5D0 → 7F2 transition, responsible for the red color emission of complexes. The higher photoluminescence intensity of ternary europium(III) complexes C2–C5 as compared to binary complex C1, suggest that ancillary ligands neo, batho, phen and bipy enhance the process of sensitization from ligand (m-EFBA) to europium(III) ion. The luminescence decay time and quantum efficiencies of the complexes were determined to estimate the efficiency of energy transfer from ligand to metal ion. In addition, the Judd–Ofelt intensity parameters (Ω2, Ω4) were calculated from the emission intensities of 5D0 → 7F2 and 5D0 → 7F4 transitions of europium(III) ion respectively. The intramolecular energy transfer mechanism of the complexes were also investigated and results indicate that the ligand (m-EFBA) and ancillary ligands effectively transfer the energy to that of Eu(III) ion.