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

Abstract

Six green glowing terbium (III) complexes were fabricated via grinding method utilizing a prime organic ligand (L) and nitrogen donor ancillary ligands. Characterization of synthesized complexes was accomplished through various spectroscopic techniques. The significant thermal stability was determined by thermogravimetric analysis while the energy bandgap and Urbach energy were investigated through diffused reflectance spectra of these complexes. The peak observed at 548 nm in emission spectra is responsible for the virescent color of these complexes. Color purity, decay time, quantum yield, and emission intensities of ternary complexes were significantly improved as compared to binary ones due to the synergistic effect of ancillary ligands. Judd-Ofelt parameters were determined by the NIR absorption spectrum, which claims the asymmetric environment around the terbium (III) ion. CCT values advocate the applicability of these complexes in green light-emitting materials as a cool light source. The biological assignments reveal the significance of these complexes as potent antioxidants and antimicrobial agents. The energy transfer process highlights the enhancement of luminescence in these complexes via the synergic effect of ligands. Our investigation portrays that these complexes can be employed in laser technology, display devices, semiconductors, biological fields, and optoelectronic devices.

Highly Luminescent Lanthanide Metal‐Organic Frameworks with Tunable Color for Nanomolar Detection of Iron(III), Ofloxacin and Gossypol and Anti‐counterfeiting Applications

“…5 D j ) for the efficient Ln 3 + sensitization are 2000-5000 cm À 1 for Tb 3 + and 2500-4000 cm À 1 for Eu 3 + . [32,34,35] For NIIC-1-Tb ΔE(T 1-5 D 4 ) is close to the indicated range, while for NIIC-1-Eu ΔE(T 1-5 D 0 ) is well outside the optimal range, indicating the possibility of an efficient energy transfer from HL 3À only to Tb 3 + cations, consistent with the observed difference in quantum yields.…”

“…The lowest emission energy levels are 20500 cm −1 for 5 D 4 of Tb 3+ and 17300 ⋅ cm −1 for 5 D 0 of Eu 3+ , [31,32] therefore, the energy gaps are ΔE(T 1 → 5 D 4 )=5100 ⋅ cm −1 and ΔE(T 1 → 5 D 0 )=8300 ⋅ cm −1 , which are both much greater than 1500 cm −1 , a threshold for the backward transfer from Ln 3+ to the ligand, [33] indicating the backward transfer improbable. Furthermore, according to Latva's empirical rule, the optimal energy gaps ΔE(T 1 → 5 D j ) for the efficient Ln 3+ sensitization are 2000–5000 cm −1 for Tb 3+ and 2500–4000 cm −1 for Eu 3+ [32,34,35] . For NIIC‐1‐Tb ΔE(T 1– 5 D 4 ) is close to the indicated range, while for NIIC‐1‐Eu ΔE(T 1– 5 D 0 ) is well outside the optimal range, indicating the possibility of an efficient energy transfer from HL 3− only to Tb 3+ cations, consistent with the observed difference in quantum yields.…”

Robust lanthanide MOFs as multifunctional luminescent sensors for intelligent visualization monitoring of MEAA and texture code anti-counterfeiting applications

“…Moreover, the optimum energy gaps DE (T1 -5 D j ) of efficient sensitization for Eu 3+ and Tb 3+ were 2500-4000 cm À1 and 2000-5000 cm À1 , respectively, in light of Latva's rule of thumb. 56,57 The DE Eu was well beyond the indicated range, whereas DE Tb was within the optimal range, indicating a higher probability of effective energy transfer from the L 2À to Tb 3+ . The schematic energy transfer diagram discussed above is depicted in Fig.…”

Ln‐MOF‐Based Hydrogel Films with Tunable Luminescence and Afterglow Behavior for Visual Detection of Ofloxacin and Anti‐Counterfeiting Applications

“…The photoluminescence quantum yields of NIIC-2-Tb and NIIC-2-Eu were 79% and 13%, respectively. According to Latva's rule, [47][48][49] the energy difference between the triplet state (T 1 ) of the ligand in NIIC-2-Ln and the lowest emission level of Ln 3+ (ΔE = 5330 cm −1 ) is closer to the optimal range required for Tb 3+ sensitization (2000-5000 cm −1 ), whereas for Eu 3+ this difference (ΔE = 8530 cm −1 ) is much farther from the optimal range (2500-4000 cm −1 , Figure S12, Supporting Information). Therefore, the luminescence yield of NIIC-2-Tb is much higher than that of NIIC-2-Eu.…”