Exploring the role of neutral ligands in modulating the photoluminescence of samarium complexes with 1,1,1,5,5,5-hexafluoro-2,4-pentanedione.

Four eight-coordinated luminescent samarium complexes of type [Sm(hfpd)3L2] and [Sm(hfpd)3L'] [where hfpd = 1,1,1,5,5,5-Hexafluoro-2,4-pentanedione L = tri-octyl-phosphine oxide (TOPO) and L' = 1,10-phenanthroline (phen), neocuproine (neoc) and bathocuproine (bathoc) were synthesized via a stoichiometrically controlled approach. This allows for precise control over the stoichiometry of the complexes, leading to reproducible properties. This investigation focuses on understanding the impact of secondary ligands on the luminescent properties of these complexes. Infrared (IR) spectra provided information about the molecular structures, whereas 1H and 13C nuclear magnetic resonance (NMR) spectra confirmed these structural details along with the coordination of ligands to trivalent Sm ion. The UV-vis spectra revealed the molar absorption coefficient and absorption bands associated with the hfpd ligand and photoluminescence (PL) spectroscopy demonstrated intense orange-red emission (648 nm relative to 4G5/2 → 6H9/2) from the complexes. The Commission Internationale de l'Éclairage (CIE) triangles indicated that the complexes emitted warm orange red light with color coordinates (x, y) ranging from (0.62, 0.36) to (0.40, 0.27). The investigation of the band gap as well as color parameters confirms the utility of these complexes in displays and LEDs.

Computational and optoelectronic investigations of red-emissive europium (III) ß-diketonate with n-donor ligands for display applications.

Europium complexes exhibiting red luminescence were prepared by employing ß-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.

Optical, electrochemical and photophysical analyses of heteroleptic luminescent Ln(iii) complexes for lighting applications.

A series of lanthanide complexes have been synthesized with fluorinated 1,3-diketones and heteroaromatic ancillary moieties. Spectroscopic studies reveal the attachment of the respective lanthanide ion to the oxygen site of ß-diketone and nitrogen site of auxiliary moieties. The conducting behavior of the complexes is proposed by their optical energy gaps which lie in the range of semiconductors. The emission profiles of the lanthanide complexes demonstrate red and green luminescence owing to the distinctive transitions of Sm3+ and Tb3+ ions, respectively. Energy transfer via antenna effect clearly reveals the effective transfer of energy from the chromophoric moiety to the Ln3+ ion. The prepared conducting and luminescent Ln(iii) complexes might be employed as the emitting component in designing OLEDs.

Synthesis of green emissive terbium(III) complexes for displays: Optical, electrochemical and photoluminescent analysis.

A series of heteroleptic terbium(III) complexes with fluorinated 2-thenoyltrifluoroacetone (TTFA) and other heteroaromatic units have been synthesized. The developed heteroleptic complexes were inspected via elemental study, cyclic voltammetry, thermal analysis and spectroscopic investigations. Optical band-gap data proposed the conducting property of prepared complexes. The photoluminescence emission profiles illustrated peaks based on terbium(III) cation (Tb3+ ) positioned at ~617, 586, 546 and 491 nm, imputed to 5 D4 to 7 FJ (J = 3,4,5,6) transitions separately. Most intense peak at 546 nm corresponding to 5 D4 → 7 F5 transition is accountable for the green emissive character of developed complexes. The luminous character of complexes reveals the sensitization of Tb3+ by ligands. Color parameters further corroborates the green emanation of Tb3+ complexes. The photometric characteristics of complexes recommended their usages in designing display devices.

Mononuclear luminous ß-diketonate Ln(III) complexes with heteroaromatic auxiliary ligands: synthesis and luminescence characteristics.

A series of lanthanide (samarium and terbium) ß-diketonates with heteroaromatic auxiliary ligands was synthesized. The prepared complexes were characterized through electrochemical, thermal, and spectroscopic analyses. Infrared analysis revealed the binding of the respective metal ion to oxygen and nitrogen atoms of diketone and ancillary ligands. Thermogravimetry/differential thermogravimetry profiles provided thermal information and specified the high thermal stability of the prepared complexes. The complexes exhibited the sharp and structured Ln-based emission in the visible region upon irradiation in the ultraviolet range. Photophysical analysis demonstrated the green and orange-red emission due to the respective characteristic transitions of Tb3+ and Sm3+ ions. Photophysical properties affirmed the luminous behaviour of the synthesized complexes. These luminous lanthanide complexes could be used as emitting materials in the design of organic light-emitting diodes.

Red emissive ternary europium complexes: synthesis, optical, and luminescence characteristics.

Solid ternary europium complexes consisting of fluorinated ß-diketone (thenoyltrifluoroacetone, TTFA) and heteroaromatic bidentate auxiliary ligands were synthesized. The luminescence features of the complexes were estimated using various spectral measurements and clearly proved that the Eu3+ ion is efficiently sensitized by ligands by an antenna effect. Photoluminescence excitation spectra have shown that Eu(III) complexes are excited effectively in the ultraviolet (UV) region and the corresponding emission spectra consist of characteristic peaks attributed to the 5 D0 →7 FJ transitions of the europium ion with the strongest emission peak at 611 nm (5 D0 →7 F2 ). From photoluminescence (PL) data, decay time, Judd-Ofelt parameters, transition rates, and quantum efficiency of the complexes were also determined. The Commission Internationale de l'éclairage (CIE) colour coordinates indicated the bright red emission of ternary europium complexes. Correlated colour temperature values indicated the utilization of these complexes in display devices. Judd-Ofelt and photophysical parameters were also estimated theoretically using LUMPAC software. Various frontier molecular orbitals and their respective energy were determined. These red emissive europium complexes could be utilized for fabricating solid-state lighting systems.

Fluorinated ß-diketone-based Sm(III) complexes: spectroscopic and optoelectronic characteristics.

The synthesis and characterization of a series of octa-coordinated Sm(III) complexes with 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione (TFNB) and 2,2'-bipyridine (Bpy) derivatives as ancillary ligand are described here. The complexes were analyzed by elemental, spectroscopic such as infrared spectroscopy, 1 H NMR, and thermogravimetric analyses. The fluorinated TFNB ligand absorbs in the range from 200 to 400 nm. The complexes show the sharp and structured Sm-based emissions in visible region upon irradiation in UV range. Excitation spectra of complexes show similarity to the absorption spectra of ligands suggesting that excitation energy is transferred from ligands to Sm(III) centre by the antenna effect. Photoluminescence emission spectra and colour parameters affirmed that the complexes show luminescence in orange-red region. These luminous Sm(III) complexes might be applied as emissive layer in organic electroluminescent devices.

Luminescent Features of Ternary Europium Complexes: Photophysical and Optoelectronic Evaluation.

Trivalent europium complexes exhibit good luminescent characteristics. A series of octacoordinated ternary europium complexes with fluorinated diketone and heteroaromatic auxiliary unit were synthesized. The synthesized europium complexes were characterized by elemental, thermal, electrochemical and spectroscopic analyses. Band gap values lie in range of semiconductors which confirm the conducting behavior of prepared complexes. Photoluminescence spectra were recorded in solid state and DMSO solvent. Emission spectral profiles have displayed most intense peak at ~ 612 nm corresponding to hypersensitive 5D0 → 7F2 transition. Colorimetric parameters suggest red luminous nature of europium complexes. The luminescent heteroleptic europium complexes might be utilized as emissive materials for fabricating display.

Red-emitting ß-diketonate Eu(III) Complexes With Substituted 1,10-phenanthroline Derivatives: Optoelectronic and Spectroscopic Analysis.

A series of europium diketonate complexes with 1-phenyl-1,3-butanedione (PBD) and 1,10-phenanthroline derivatives were synthesized and explored spectroscopically. Photophysical characteristics of synthesized complexes have been investigated experimentally as well as theoretically. Photoluminescence emission spectra of complexes do not contain any peak of ligand revealing efficient transferal of energy from ligand to Eu3+ ion. Presence of peak at 611 nm corresponding to 5D0 → 7F2 transition is responsible for red emanation of ternary europium complexes. Photophysical parameters viz., Judd-Ofelt, quantum efficiency, radiative and non radiative decay rates were also estimated theoretically from LUMPAC software. Geometry optimization of complexes was done via Avogadro software. All synthesized trivalent complexes exhibit red emission which was further sustained by the position of chromaticity coordinates in CIE triangle. These red emanating materials could be utilized in designing electroluminescent display devices.

Synthesis, Optoelectronic and Photoluminescent Characterizations of Green Luminous Heteroleptic Ternary Terbium Complexes.

This article presents four ternary terbium complexes based on fluorinated 2-thenoyltrifluoroacetone (TTFA) and N donor bidentate neutral ligands. The prepared complexes were examined by elemental study, electrochemical analysis, spectroscopically and thermo-gravimetrically. Spectral analysis shows the bonding of Tb3+ ion with oxygen and nitrogen atom of diketone and neutral ligand respectively. Upon excitation in UV region, synthesized terbium complexes show luminescence in green region of electromagnetic spectrum. Photoluminescence emission spectra of complexes do not show any ligand based peak suggesting the effective transferal of energy from ligand to metal ion. Green emanation by terbium complexes is owing to intense peak ~547 nm (5D4 → 7F5). The outcome of emission data and CIE coordinates correlate with each other and affirms the utility of green luminous complexes as potential emissive material for optoelectronic gadgets applied in lighting system.