Designing and Judd-Ofelt evaluation of versatile luminescent Eu (III) complexes sensitized with ß-diketone ligand for multifarious applications.

The present research work entails the synthesis of one binary and four ternary red light-emitting Eu (III)-based complexes with 3-benzylidene-2,4-pentanedione as the main ligand and 1,10-phenanthroline, bathophenanthroline, neocuproine, and 4,4'-'dimethyl-2,2'-'bipyridyl as auxiliary ligands. The metal-organic framework of the series was elucidated using energy dispersive X-ray analysis, elemental analysis, Fourier transform infrared spectroscopy, and proton nuclear magnetic resonance. This Eu (III) series exhibits optimum thermal stability, making them a promising candidate for organic light-emitting diodes. On the basis of emission spectra, their optical parameters such as nonradiative and radiative decay rates, luminescence decay time, intrinsic quantum efficiency, and Judd-Ofelt intensity parameter were determined. The monocentric luminescence and Judd-Ofelt parameters reveal the absence of symmetry around the europium center. CIE chromaticity coordinates, correlated color temperature values, color purity, and asymmetric ratios authenticate the color coordinates of the complexes in red region. Optical band gap values lie within the range of wide band gap semiconductors, indicating their utilization in military radars and biological labeling.

Structural Insights and Photophysical Screening of Sm (III) Complexes with Heterocyclic Ligand for Optical Applications.

Five novel bright orange color emitting Sm(III) complexes (C1-C5) have been synthesized via energy efficient and cost effective solution precipitation method with 5-phenyl 2-furoic acid as primary organic sensitizer and nitrogen donor neocuproine, 2, 2- bipyridyl, bathophenanthroline, and 1,10-phenanthroline as secondary ligands. All the newly synthesized metal complexes are thoroughly characterize to examine the appropriateness of the organic ligand for the sensitization process. All the outcomes of the various advanced and fundamental spectroscopic techniques validate the bonding of carboxylate group with the Sm(III) ion. The luminescence spectra reflects the dominance of magnetic dipole transition which designate the occurrence of harmonized chemical environment in the coordination sphere which is further validated by enhanced values of intensity ratio. These complexes possess suitable thermal stability with excellent photoluminescent features as confirmed by thermogravimetric analysis and photoluminescence studies. The luminescence lifetime of samarium complexes [C2-C5] is relatively long due to the synergistic effect presented by ancillary ligands. The emission color of the synthesized complexes show shift from orange to bright orange red color which is displayed through CIE color coordinates.

Investigations into spectroscopic and optoelectronic behaviour of furoic acid-based Eu(III) complexes for advanced photonic applications.

To illuminate the zone of organic light-emitting diodes, a novel series of four red luminescent europium complexes, one binary (C1) and three ternary (C2-C4), of 5-phenyl 2-furoic acid was synthesized with 2,2'-bipyridyl (bipy), bathophenanthroline (batho) and 1,10-phenanthroline (phen) as ancillary ligands and characterized by adopting various analytical techniques. All the findings of energy-dispersive X-ray spectroscopy, elemental (CHN) analysis, Fourier transform infrared, nuclear magnetic resonance, and ultraviolet-visible spectroscopy confirmed the coordination of ligand binding sites with the europium ion. To evaluate the thermal stability, thermogravimetric/difference thermogravimetric measurements were taken that revealed that the synthesized complexes were stable up to 245°C. Diffused reflectance studies indicated that these complexes had potential for their use in wide band-gap semiconductors, as all the four complexes showed metal-centred luminescence as a characteristic red emission peak that was observed at 613 nm under the excitation wavelength of 330 nm. The internal quantum efficiencies and luminescence lifetime of complexes were predicted using Judd-Ofelt and photophysical data. The monoexponential luminescence decay and Judd-Ofelt analysis suggested the presence of a single and asymmetric chemical environment in the coordination sphere of the europium metal. Commission International de l'Eclairage colour coordinates, correlated colour temperature values, and colour purity of the complexes validated their red emission in the visible region.

New Insights into Optoelectronic Features of Eu(III) Complexes with Heterocyclic Ligand for Advanced Optical Applications.

Our present technological society needs the assistance of lanthanide luminescence in almost every field to meet the global energy demands. In present research work we have synthesized five (one binary and four ternary) 5-(4-methylphenyl)-2- furoic acid based Eu(III) complexes with ancillary ligands, namely, aqua (H2O), neocuproine (neo), 2, 2'-bipyridyl (bipy), bathophenanthroline (batho) and 1, 10-phenanthroline (phen). The spectroscopic analysis and photophysical features are characterized by the use of different investigative techniques. All the findings obtained from EDAX, elemental (CHN) analysis, FT-IR, NMR, UV-visible spectroscopy declared the coordination of ligand binding sites with the europium ion. These Eu(III) complexes possess good thermal stability and excellent optoelectronic features as predicted with the help of TGA and PL analysis. Diffuse reflectance spectral studies confirm their applications in the wide band gap semiconductors. The Judd-Ofelt analysis and monoexponential behavior of lifetime reveals the existence of asymmetric and single local environment around europium ion. All the complexes show sharp red emission validated by CIE color coordinates, color purity, asymmetric ratio and CCT values. SEM analysis tells that the bulk of these complexes comprised of spherical shaped particles with uniform distribution.