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•The synthetic procedure and spectroscopic characteristics of the complexes were discussed in detail.•The red emission of europium complex was due to hyperintense peak situated at ...about 612 nm.•Information regarding photophysical parameters including structural asymmetry, rigidity and radiative transition probabilities were obtained via JOES.•Absorption and photoluminescence analyses suggest the application of synthesized complexes in fabrication of display devices.
Europium complexes exhibiting red luminescence were prepared by employing β-diketone as main ligand and 1,10-phenanthroline as an additional ligand. Various methods, including 1H NMR, IR spectroscopy and analysis of optical band gap were employed to examine these complexes. The luminescent photophysical properties were investigated using PL spectroscopy and theoretical calculations were conducted to explore radiative transitions probabilities and Judd-Ofelt (J-O) parameters for transitions of type 5D0 → 7F2, 4. J-O parameters were determined using the JOES computer program and results were in good agreement with the outcomes obtained experimentally. The luminescence analysis results have verified the vibrant, single-color red emission of the prepared complexes. The band gap of ternary europium complexes, determined optically, electronically, and theoretically, falls within the range of 3–4 eV. This similarity indicates that these complexes are potentially suitable as semiconductor materials. The results from absorption, electrochemical and photophysical analyses indicate the potential use of synthesized complexes in lighting and display applications.
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•Octacoordinated luminous Dy(III) complexes were synthesized with DPD and 1,10-phenanthroline derivatives.•IR and 1H NMR studies suggest the bonding between organic moieties and Dy3+ ...ion.•Hypersensitive peak around 575 nm corresponding to 4F9/2 → 6H13/2 transition is responsible for yellow emission.•Dysprosium’s conducting and thermally stable complexes demonstrate their use in fabricating OLEDs.
Several luminescent ternary dysprosium complexes were synthesized and examined using diketone ligand 1,3-diphenylprop-1,3-dione (DPD) and various auxiliary ligands. Spectroscopic analysis was carried out to determine the structural and photophysical features of Dy (III) complexes. IR and proton NMR spectroscopic studies suggested the bonding of chelating moieties to the metal ion through oxygen and nitrogen atom. The optical and electronic band gap is evaluated which proposed the conducting behaviour of dysprosium complexes. Upon excitation with UV radiation, three distinct emission peaks of the Dy (III) ion are appeared at about 485 nm (J = 15/2), 575 nm (13/2) and 664 nm (11/2) corresponding to the transitions of type 4F9/2 → 6HJ. The strongest emission peak obtained at ∼ 575 nm is responsible for yellow emission of Dy (III) complexes. The yellow to blue (Y/B) ratio estimated for the transition J = 13/2 / J = 15/2 were found to be in the range of 4.19 – 2.80. The quantum yield was also determined for the Dy (III) complexes which is as: Φ1 = 0.315, Φ2 = 0.261, Φ3 = 0.183, Φ4 = 0.157. The synthesized dysprosium complexes demonstrate luminescence lifetime in decreasing order i.e. 0.600 ms > 0.510 ms > 0.431 ms > 0.323 ms. Furthermore, the chromaticity coordinates also confirm their yellow luminous behavior. These newly synthesized complexes could be utilized for developing systems significant for lighting, OLEDs and displays due to their luminous features.
Dysprosium (Dy3+) containing four single-molecule complexes with 1,3-diketone ligand, TFPB (4,4,4-trifluoro-1-phenyl-1,3-butadionate) along with neutral co-ligands of varying denticity were ...synthesized and two of them were explored as potential sources of near-white light emission. The choice of ligand as well as the coordination surroundings of Dy(III) ion significantly influence the blue (B: 4F9/2 → 6H15/2) and yellow (Y: 4F9/2 → 6H13/2) emissions. The inclusion of the auxiliary ligand such as topo in D1 leads to reduction in emission intensity compared to D2-D4 due to less effective sensitization. At room temperature, the CIE color coordinates for complexes D1 and D4 approach the coordinates of perfectly balanced and idealized white light (0.333, 0.333). Furthermore, Correlated Color Temperature (CCT) values for D1 and D4 characterize them as cold-white-light emitters, while the complexes D2 and D3 are categorized as a neutral-light emitter. In addition to their visible emissions, the semi-conducting properties and suitable deactivation lifetime corresponding to these synthesized complexes (D1-D4) have also been extensively studied and found potential applications in basic research, security printing, sensors, detectors and OLEDs.
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•Synthesized luminescent dysprosium complexes incorporating 1,3-diketone and neutral ligands.•Investigated PL emission spectra for understanding their near-white and yellow emission.•Quantified the complex's color in terms of CIE 1931 color space with measurement of the intensity of color.•Compared photoluminescent properties of complexes on the basis of denticity of coordinating moieties.
The set of four ternary coordination compounds of terbium were prepared with diketone 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione (TFDH) and four different neutral ligands (L) having formula ...Tb(TFDH)3L. Resulting compounds were characterized using different techniques including NUV absorption studies, photoluminescence (PL) spectroscopy, electrochemical and thermal analyses. PL spectra confirmed the green luminescence of synthesized complexes by exhibiting characteristic dominant 5D4 → 7F5 peak around 545 nm. Electronic and optical energy gap values lying at ∼3.5 eV reveals their potential to use in semiconductor materials. All the spectral results are in good agreement with each other and highlight their utility in lighting, biomedical imaging and sensors etc.
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•Ternary Tb(III) complexes were prepared using β-diketone and 1,10-phenanthroline based neutral ligands.•NMR spectra exhibited dipolar shift due to the paramagnetic nature of terbium ion.•The optical band gap and the electronic band gap lie within the semiconductor range.•5D4.→ 7F5 MD transition is responsible for the green luminescence in the synthesized complexes.
•Coordination sphere effects: Spectroscopic analysis of samarium β-diketonate complexes.•Emission peak at 648 nm: Electric dipole transition responsible for characteristic orange-red ...emission.•Spectroscopic evidence confirms octacoordinated samarium ion with carbonyl oxygen and nitrogen coordination.•Semiconducting properties and good thermal stability suggested display applications.
Ternary Sm(III) complexes of general representation Sm(TFDH)3L were synthesized to understand influence of different auxiliary moieties on their optoelectronic properties. The synthesized complexes were thoroughly investigated using elemental, IR, NMR, UV and PL studies. In these complexes, the emitting metal ion is bonded with six O atoms from di-ketone 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione and two nitrogen atoms from neutral ligand i.e. 1,10-phenanthroline and its derivatives. Proton NMR spectral data showed that samarium ion induced chemical shift is dipolar in nature. The photoluminescence analysis showed that the complexes show intense orange-red emission due to 4G5/2 → 6H9/2 transition. Moreover, CIE color coordinates supported the results obtained from photoluminescence study, providing additional confirmation of the luminescent properties of prepared complexes within the orange-red region. Their utility in displays and OLED's was confirmed by studying their optical and electronic band gaps.
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•Synthesized samarium-centered ternary complexes incorporating ‘TFPB’ & various neutral moieties having different denticities.•Explored the vibrational modes in the IR spectra to identify ligand ...coordination and discussed the changes in IR spectra upon complex formation.•Studied photoluminescence spectra and energy transfer phenomenon to understand the influence of different coligands on the luminescence intensity.•Most intense transition at around 648 nm as a consequence of ΔJ = 2 transition, indicates the pronounced asymmetry in the chelation environment surrounding the central ion.•The synthesized complexes display conductive properties, a notably extended luminescent lifespan and color space parameters in orange-red region, indicating their potential utility in photonic devices.
The synthesis and characterization of four octacoordinated complexes of Sm(TFPB)3 with different neutral ligands have been successfully performed. This study aimed to evaluate the potential of neutral ligands in enhancing the emission intensity of Sm(III) ion by investigating their light-emitting characteristics. Dominance of hypersensitive transition 4G5/2 → 6H9/2 is observed which suggests the asymmetry in the vicinity of Sm(III) ion in these complexes, reinforced by asymmetry ratio. Stark-splitting in the magnetic dipole 4G5/2→6H5/2 transition was consistent across most complexes, but Sm(TFPB)3(topo)2 displayed a different pattern due to monodentate auxiliary moiety, which does not provide as much structural rigidity and stability as found in the other complexes. Various analyses including IR, NMR, CV, TGA, UV and colorimetry, supported possible applications of synthesized complexes in devices based on photonics, sensors, magnets and other technological fields.
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In this current study, we have synthesized four europium(III) complexes utilizing a tri-fluorinated β-diketone moiety: 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione (TFDH) with auxiliary ligand: 2,2′- ...bipyridine and its derivatives. FTIR, UV–Vis and luminescence spectroscopic characterizations were implemented for evaluation of the bonding and luminous characteristics in synthesized europium(III) complexes. Eight-coordination environment around Eu3+ ion has been demonstrated by 1H NMR spectral data. Photoluminescence (PL) study of these complexes has been carried out in powdered form. Characteristic red emitting behavior of Eu(III) ion was observed corresponds to the transition of 5D0→7F2 in PL spectra of Eu(III) complexes. The CIE (Commission Internationale de l'Eclairage) chroma coordinates 1931 and CCT (Correlated Color Temperature) values were derived from the information obtained from the emission spectra. The Judd-Ofelt intensity parameters (Ωτ) and excited state deactivation time (τ) in solid state have also been estimated. In the synthesized Eu(III) complexes, the europium ion was present in a highly polarizable ligand field, as demonstrated by the higher values of Ω2. Values of band gap i.e. optical and electronic as well as the red luminous nature of prepared complexes showed up their utilization in display devices.
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•Octa coordinated Eu(III) complexes were synthesized using 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione and N-donor ancillary ligand.•Most intense peak at ∼612 nm relative to 5D0.→7F2 transition was responsible for the characteristic red emission of europium complexes.•Computational analyses were performed with the help of JOES, Avogadro interface and ORCA.•The band gap as well as the red luminous behavior suggests the utilization of Eu(III) complexes in lighting and display applications.
In this study, β-diketone (1,1,1-trifluoroacetylacetone, tfaa) based mononuclear anhydrous octacoordinated dysprosium complexes i.e. Dy(tfaa)3(TOPO)2 (D1), Dy(tfaa)3(phen) (D2), Dy(tfaa)3(NeoC) (D3) ...and Dy(tfaa)3(BathoC) (D4) were synthesized using four different neutral ligands. The effect of different sensitizers on Dy(III) ion is analyzed using various spectroscopic and analytical techniques. The composition and bonding were examined by elemental analysis, infrared spectroscopy, NMR spectroscopy and thermal analysis (TGA). The luminescent characteristics of the synthesized complexes were further investigated. The complexes, when exposed to UV light, displayed characteristic emissions of the central Dy(III) ion. The photoluminescence spectra indicated the strongest emission intensity of D3 complex. The hyper-intense transition in all complexes is sensitive to the metal ion environment. The semiconducting nature of complexes was confirmed by optical and electronic band gap values obtained from absorption spectroscopy and cyclic voltammetric analysis, respectively. The neutral ligands (TOPO, phen and its derivatives) along with tfaa, are found to be good sensitizers for trivalent dysprosium ion. All the characteristic features of these prepared complexes show their potential applications in the fabrication of OLEDs.
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•Ternary Dy-tfaa complexes were synthesized by employing monodentate & bidentate as ancillary ligand.•The mechanism of energy transfer demonstrates the efficient sensitization of Dy(III) ion occurs via photosensitizing ligands.•The hypersensitive electric dipole peak noticeable at around 575 nm due to 4F9/2 → 6H13/2 transition is responsible for the yellow emission.•Cyclic voltammetric and Tauc's analyses were conducted to study the redox behavior, electronic band gap and optical band gap, respectively.
•Synthesized dysprosium (III) complexes by utilizing TFDH with 2,2ʹ-bipyridyl and its derivatives.•FTIR and NMR confirmed coordination via oxygen and nitrogen donor atoms in ternary ...complexes.•Semiconducting behavior of complexes confirmed by optical and CV band gap values.•High luminescence lifetimes suggested applications in display devices.
The ternary dysprosium complexes involving 1,1,1-trifluoro 5,5-dimethyl 2,4-hexanedione (TFDH) along with 2,2ʹ-bipyridyl and its derivatives have been synthesized. Elemental, infrared and proton NMR analyses were used to evaluate the bonding patterns between dysprosium ion and organic moieties. UV–Visible and photoluminescence spectroscopy were used to examine the optical characteristics. To confirm the anhydrous nature of synthesized complexes, IR and thermogravimetric data were utilized. The band gap value lies in semi-conducting region was explained by Tauc's plot and CV curve, respectively. The photophysical characteristics of dysprosium complexes have been studied in powdered form. The appearance of yellow luminescence on irradiation under NUV-light indicates a highly efficient transfer of energy mechanism from organic ligand to the Dy(III) ion. The CCT values were found to be suitable for cold light sources. The ∆J = 2 transition dominates the overall emission spectra with branching ratio ∼70% is ideal for laser reinforcement. The synthesized Dy(III) complexes possess band gap in semi-conducting range, good thermal stability and high luminous properties, which makes them suitable for applications in displays and lighting technologies.
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