A europium complex with enhanced long-wavelength sensitized luminescent properties

Abstract

We report a new complex Eu(tta)(3).bpt (tta = thenoyltrifluoroacetonate; bpt = 2-(N,N-di-ethylanilin-4-yl)-4,6-bis(pyrazol-1-yl)-1,3,5-triazine) with excellent long-wavelength sensitized luminescent properties, in which four hydrogen atoms replace the methyl groups at the 3,3'- and 5,5'-positions of the pyrazolyl rings in a previously reported complex Eu(tta)(3).dpbt. Upon visible-light excitation (lambda(ex) = 410 nm) at 295 K, the quantum yield (Phi(Ln)(L)) of Eu(3+) luminescence of Eu(tta)(3).bpt is higher by 23% than that of Eu(tta)(3).dpbt. Different from the case of Eu(tta)(3).dpbt, Phi(Ln)(L) of Eu(tta)(3).bpt increases linearly with the decrease in temperature. Because of the different coordination environments around Eu(3+) ion, the fine structure of the hypersensitive (5)D(0)-->(7)F(2) emission band of Eu(tta)(3).bpt is quite different from that of Eu(tta)(3).dpbt, with the strongest emission line locating at 620 nm rather than 613 nm where the strongest emission line of Eu(tta)(3).dpbt appears. The excitation window of Eu(tta)(3).bpt is much broader than that of Eu(tta)(3).dpbt with a red edge extending up to 450 nm in a dilute toluene solution (1.0 x 10(-5) M) and 500 nm in a toluene solution (1.0 x 10(-2) M). Eu(tta)(3).bpt also exhibits excellent two-photon-excitation luminescent properties.

Efficient Visible‐Light‐Excitable Eu3+ Complexes for Red Organic Light‐Emitting Diodes

“…These complexes are good candidates for less‐harmful biomarkers and can be used in optoelectronic applications as low‐voltage driven emitting species . Even though high Q Ln L values (> 0.80) are widely reported for the UV‐excitable Eu 3+ complexes, reports quantifying the emission quantum yield of visible‐light‐excitable Eu 3+ ‐based complexes are scarce , . In all of these examples, the enhancement of the Eu 3+ sensitization in the visible spectral range was achieved through chemical modifications of the ligand structure with an expanded π‐conjugated system and using either neutral tris‐ ( Q Ln L = 0.75 at 415 nm and 0.40 at 400 nm) or anionic tetrakis‐Eu 3+ ‐β‐diketonates ( Q Ln L = 0.80 at 410 nm and Q Ln L = 0.45 at 400 nm).…”

Noninvasive and real-time pharmacokinetics imaging of polymeric nanoagents in the thoracoepigastric vein networks of living mice

“…The Eu-luminescent complex, EuðfodÞ 3 dpbt, was synthesized as previously reported. 67,70 Briefly, the benzene solutions of EuðfodÞ 3 · 3H 2 O (51.9 mg, 0.05 mM) and dpbt (20.8 mg, 0.05 mM) were mixed under argon atmosphere and stirred for 3 h. The mixture was then evaporated to remove the solvents and further dried in vacuum to obtain the EuðfodÞ 3 dpbt complexes. Poly(methyl methacrylate-co-methacrylic acid) (PMMA-MAA) was used as the matrix material for the fabrication of the Euluminescence-labeled polymeric nanoparticles.…”

“…[59][60][61][62] TPE bioimaging has been benefiting from the development of high-performance TPE chromophores as exogenous labels. In this relation, we have devised a number of highly efficient europium (Eu)-luminescent complexes exhibiting large two-photon absorption (TPA) cross sections at near-infrared photosensitization wavelengths [63][64][65][66][67] and have succeeded in incorporating such complexes into specific polymeric nanocarriers for in vivo pharmacokinetics imaging. 68 Based on these advances, we have recently built a TPE and time-resolved (TPE-TR) bioimaging apparatus to analyze the spatiotemporal evolution of the nanocarriers in small animals.…”

Lanthanides in Solar Energy Conversion

“…Triazine-based ligands have excellent sensitization properties for the luminescence of europium up to 400-410 nm (Xue et al, 2010) and some of them display sizeable two-photon absorption cross-sections (Lo et al, 2011) so that in addition to dpbt (Scheme 1) several triazinyl ligands have been tested for use in LSCs (Scheme 2) (Katsagounos et al, 2011) to one end of which a multicrystalline silicon (m-Si) solar cell with 15% conversion yield was attached. No quantitative data on the photophysical properties of the metal complexes are given, but [Eu(NO 3 ) 3 (trz1) 2 ] appears to be the most luminescent and it is also the most effective in LSCs.…”