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

Abstract

Five new europium(III) complexes Eu(p-EFBA).(HO) (C1), Eu(p-EFBA).neo (C2), Eu(p-EFBA).batho (C3), Eu(p-EFBA).phen (C4), Eu(p-EFBA).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 (H-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 (Ω Ω) of the complexes. The higher value of intensity parameter Ω associated with hypersensitive D → F transition of europium(III) ion revealing highly polarizable ligand field. The purposed energy transfer mechanism of complexes indicates the efficient energy transfer in complexes.

Augmentation of photophysical features and Judd–Ofelt analysis of extensively green glowing terbium (III) complexes with nitrogen donor ancillary ligands

“…The peak due to aromatic protons of quinoline is split at 8.9 ppm and 9.1 ppm in ligand, which gives a multiplet from 7.61 to 9.23 ppm in the complex. Hence we can conclude that the complexes are present in zwitter ionic form and the appearance of broadband was explained on the basis of the paramagnetic nature of terbium ion claims the complex formation [5,6,26].…”

Enhanced Optoelectronic and Biological Potential of Virescent-Glowing Terbium(III) Complexes with Pyrazole Acid

“…35 The luminous intensity of ternary complexes is apparently increased because secondary ligands produce rigid and asymmetric environment in coordination spheres of these complexes, which provides protection against environmental quenching generated through vibrations of high energy O-H oscillators found in water molecules in the coordination sphere of the C1 (binary) complex. 36 Therefore, the enhanced emission performance of these complexes corroborates the appropriateness of these lightemitting complexes in various advanced photonic devices. 37 The radiation absorbed by the luminescent material in photonic devices (e.g.…”

Designing and Judd–Ofelt evaluation of versatile luminescent Eu (III) complexes sensitized with β‐diketone ligand for multifarious applications

“…Moreover, the synergistic effect of bidentate nitrogen donors enhances the outcome of luminescence intensity of Eu 3+ complexes (E2‐E4) in which the main ligand BP and auxiliary ligands function simultaneously in populating the 4f excited state of Eu 3+ by transferring the energy. The S 1 and T 1 states of bidentate nitrogen donors are taken from reported literature (Table 6) [20–43]. The energy transfer process is the same as that in E1‐E5 complexes, so as an example, the energy level diagram of E5 complexes is shown in Figure 11b.…”