Luminescent Properties of Europium Complexes with Different Long Chains in Langmuir-Blodgett (LB) Films

Abstract

A series of europium(III) complexes with different chain length, tris [2-m-pyridylmethanamido-5-phenyl- (1,3,4)-oxadiazole] mono [2-(4-n-alkylphenyl)-iminazole (4,5-f)-1,10-phenanthroline] Eu(III) [Eu(PMA)3Nn (n = 6, 10, 14,18)] were synthesized. All of these amphiphilic europium(III) complexes could form stable Langmuir film at air/water interface and could be transferred onto hydrophilic quartz and mica substrates by measurement of UV spectra in which the absorbance of the LB films at about 288 nm scales showed the linearity with the number of layers deposited. In order to investigate relation between fluorescence properties and the arrangement of molecular in LB films, surface topography of monolayer films were observed by atomic force microscopy (AFM). Results showed that the emission spectra have Eu(III) characteristic peaks and strong emission strength. It is interesting that the molecular with looser arrangement in LB films has better monochromacity, which illustrated that energy might transferred more easily from ligand to Eu(III) in loosen structure films

A Dual‐Characteristic Bidentate Ligand for a Ternary Mononuclear Europium(III) Molecular Complex – Synthesis, Photophysical, Electrochemical, and Theoretical Study

“…In the present study, the synthesized Eu III complex shows red emission owing to efficient energy transfer from the bidentate ligand and TTA to the metal ion. The excited 5 D 0 energy level of the Eu III ion is located at 17500 cm –1 , . The triplet‐state energy level is higher than the 5 D 0 energy level of the Eu III complex (ca.…”

“…A comparative study of absorption spectra of Eu(TTA) 3 Phen‐Fl‐TPA as a solid, in solution, and as a thin film (the observed flat absorption in the spectrum from λ = 430 to 800 nm is due to an instrumental artefact) was performed, and the absorption maximum shifts to longer wavelength for the solid compared with those of solution and thin film. The observed bathochromic shift in the absorption is due to the aggregation of the complex in the solid phase , . The band gaps were calculated for all the compounds by applying the Kubelka–Munk function to the UV/Vis data [Figure S9; α = F ( R ⋡ ), Equation ] ,…”

Eu(III) Complexes for LEDs Based on Carbazole- and Fluorene-Functionalized Phenanthro-Imidazole Ancillary Ligands: Detailed Photophysical and Theoretical Study

“…It is known that the singlet and triplet energy level of the TTA located at around 25164 (3.12 eV) and 18954 cm −1 (2.35 eV) . It is well identified that the Eu(III) metal ion excited 5 D 0 energy level located at 17500 cm −1 . In current observation, the synthesized Eu(III) complex shows red emission because of efficient energy transfer from both the bidentate ligand as well as TTA to center metal ion.…”

Dendrimer-based Nanoparticle for Dye Sensitized Solar Cells with Improved Efficiency

“…The lifetime of the dendritic dye was found to be 2.11 ns with a standard deviation of 0.0027 ns and that of only DL680 dye was 1.25 ns with a standard deviation of 0.0025 ns as displayed in Table 2 . Luminescent europium complexes have been reported to exhibit long lifetime and are also highly stable in terms of ligand-metal dissociation and have widely been used as donors in Forster resonance energy transfers [ 26 – 28 ]. It is therefore reasonable that upon conjugation of the europium chelate to the DL680, the luminescence lifetime is significantly extended.…”