Luminescent Lanthanide (Eu 3+ , Tb 3+ ) Hybrids with 4‐Vinylbenzeneboronic Acid Functionalized Si‐O Bridges and Beta‐Diketones

Synthesis of novel lanthanide acylpyrazolonato ligands with long aliphatic chains and immobilization of the Tb complex on the surface of silica pre-modified via hydrophobic interactions

Immobilization of a Tb acylpyrazolonato complex on silica surfaces via hydrophobic interactions.

Co-assembly and luminescence tuning of hybrids with task-specified ionic liquid encapsulating and linking lanthanide-polyoxometalates and complexes

A class of novel multifunctional hybrids assembled by lanthanide polyoxometalates, ionic liquid and lanthanide complexes were prepared through the reactions of ion exchange and coordination in mild conditions. These hybrids possess two luminescence centers, one is lanthanide polyoxometalates ([EuW10O36](9-) or [TbW10O36](9-)), the other is lanthanide complexes of 1,10-phenanthroline (phen) (or 2,2'-bipyridine (bpy)) and ionic liquid (1-methyl-3-propionic imidazole unit). Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD) analysis, thermo-gravimetric analysis (TGA), UV/vis diffuse reflectance spectra and photoluminescent properties are utilized to characterize these hybrid materials. The results reveal that all hybrids possess amorphous microstructures and are composed of inorganic polyoxometalates and lanthanide nitrate through chemical bonds. Most hybrids exhibit outstanding luminescent properties such as high quantum efficiency and long lifetimes. Moreover, the luminescent color of them can be tuned and even the white luminescence can be integrated.

Fluorescence enhancement of europium(III) perchlorate by benzoic acid on bis(benzylsulfinyl)methane complex and its binding characteristics with the bovine serum albumin (BSA)

A novel ligand with double sulfinyl groups, bis(benzylsulfinyl)methane L, was synthesized by a new method. Its novel ternary complex, EuL2.5⋅L'·(ClO4)2⋅5H2O, has been synthesized [using L as the first ligand, and benzoic acid L' as the second ligand], and characterized by elemental analysis, molar conductivity, coordination titration analysis, FTIR, TG-DSC, (1)H NMR and UV-vis. In order to study the effect of the second ligand on the fluorescence properties of rare-earth sulfoxide complex, a novel binary complex EuL2.5·(ClO4)3·3H2O has been synthesized. Photoluminescent measurement showed that the first ligand L could efficiently transfer the energy to Eu(3+) ions in the complex. Furthermore, the detailed luminescence analyses on the rare earth complexes indicated that the ternary Eu (III) complex manifested stronger fluorescence intensities, longer lifetimes, and higher fluorescence quantum efficiencies than the binary Eu (III) materials. After introducing the second ligand L', the fluorescence emission intensities and fluorescence lifetimes of the ternary complex enhanced more obviously than the binary complex. This illustrated that the presence of both the first ligand L and the second ligand L' could sensitize fluorescence intensities of Eu (III) ions. The fluorescence spectra, fluorescence lifetime and phosphorescence spectra were also discussed. To explore the potential biological value of Eu (III) complexes, the binding interaction among Eu (III) complexes and bovine serum albumin (BSA) was studied by fluorescence spectrum. The result indicated that the reaction between Eu (III) complexes and BSA was a static quenching procedure. The binding site number, n, of 0.60 and 0.78, and binding constant, Ka, of 0.499 and 4.46 were calculated according to the double logarithm regression equation, respectively for EuL2.5⋅L'⋅(ClO4)2⋅5H2O and EuL2.5⋅(ClO4)3⋅3H2O systems.

Near infrared and visible luminescence from xerogels covalently grafted with lanthanide [Sm(3+), Yb(3+), Nd(3+), Er(3+), Pr(3+), Ho(3+)] β-diketonate derivatives using visible light excitation

A series of ternary lanthanide β-diketonate derivatives covalently bonded to xerogels (named as Ln-DP-xerogel, Ln = Sm, Yb, Nd, Er, Pr, Ho) by doubly functionalized alkoxysilane (dbm-Si) was synthesized in situ via a sol-gel process. The properties of these xerogel materials were investigated by Fourier-transform infrared (FT-IR) spectroscopy, field-emission scanning electron microscopy (FE-SEM), diffuse reflectance (DR) spectroscopy, thermogravimetric analyses, and fluorescence spectroscopy. The data and analyses suggest that the lanthanide derivatives have been covalently grafted to the corresponding xerogels successfully. Of importance here is that, after excitation with visible light (400-410 nm), the xerogels all show characteristic visible (Sm(3+)) as well as near-infrared (NIR; Sm(3+), Yb(3+), Nd(3+), Er(3+), Pr(3+), Ho(3+)) luminescence of the corresponding Ln(3+) ions, which is attributed to the energy transfer from the ligands to the Ln(3+) ions via an antenna effect. Exciting with visible light is advantageous over UV excitation. Furthermore, to the best of our knowledge, it is the first observation of NIR luminescence with visible light excitation from xerogels covalently bonded with the Sm(3+), Pr(3+), and Ho(3+) derivatives. Compared to lanthanide complexes (Ln = Er, Nd, Yb) functionalized periodic mesoporous organosilica (PMO) materials that exhibit similar optical properties reported in our previous work, the Ln-DP-xerogel (Ln = Sm, Yb, Nd, Er, Pr, Ho) in this case offer advantages in terms of ease of synthesis and handling and potentially low cost for emerging technological applications. Development of near-infrared luminescence of the lanthanide materials with visible light excitation is of strong interest to emerging applications such as chemosensors, laser systems, and optical amplifiers.