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

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.

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 β-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 F_J (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 β-diketonate Ln (III) complexes with heteroaromatic auxiliary ligands: Synthesis and luminescent characteristics

A series of lanthanide (samarium and terbium) β-diketonates with heteroaromatic auxiliary ligands have been synthesized. The prepared complexes were characterized through electrochemical, thermal and spectroscopic analyses. Infrared analysis reveals the binding of respective metal ion to oxygen and nitrogen atoms of diketone and ancillary ligands respectively. TG/DTG profiles provide thermal information and specify the high thermal stability of the prepared complexes. The complexes exhibit the sharp and structured Ln-based emission in visible region upon irradiation in UV range. Photophysical analysis demonstrated the green and orange-red emission due to the respective characteristic transitions of Tb³⁺ and Sm³⁺ ions. Photophysical properties affirm the luminous behavior of synthesized complexes. These luminous lanthanide complexes could be used as emitting material in designing OLEDs.