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An aluminum 2-aminoterephthalate based metal-organic framework (MOF) material was applied for the first time to prepare highly efficient heterogeneous catalysts in desulfurization processes. Sandwich-type [Eu(PW11O39)(2)](11-) polyoxometalate (POM) was supported on Al(III) and Cr(III) MIL-type MOFs, NH2-MIL-53(Al) and MIL-101(Cr), and extensive characterization confirmed the incorporation of the POM on the two supports. The catalytic performance of the two composite materials, POM/MIL(Al) and POM/MIL(Cr), was evaluated in the oxidative desulfurization (ODS) of a model fuel containing some of the most common refractory sulfur compounds in diesel. Both composite materials have shown to be active and robust heterogeneous catalysts for the efficient removal of the sulfur-containing compounds from the model diesel, and the influence of the solid support on the catalytic performance of the active species was further assessed. The POM/MIL(Al) revealed notable catalytic performance, since complete desulfurization was obtained after 2 h of reaction. Furthermore, this remarkable heterogeneous catalyst revealed to be stable and recyclable for various catalytic cycles.

A heterotetranuclear Na2Eu2 complex with uncommon photo-luminescence properties is reported. The complex exhibits good emission efficiency at ambient temperature, coupled with strong temperature dependence of the emission intensity and lifetime in the 273-333 K range, all of which are key features for non-contact luminescence-based thermometers capable of sensing and imaging temperatures in the physiological range.

A series of fluorinated lanthanide-organic frameworks (LnOFs), formulated as [Ln(H(3)tftp)(H2O)] [where Ln(3+) = La3+ (1), (La0.95Eu0.05)(3+) (2), (La0.95Tb0.05)(3+) (3) and (La0.94Eu0.03Tb0.03)(3+) (4)], has been successfully prepared, under hydrothermal conditions, using the novel ((2,4,6-trifluorobenzene-1,3,5-triyl)tris (methylene)) triphosphonic acid (H(6)tftp) organic ligand and Ln(3+) cations as metallic centers. The three-step preparation of the tripodal H(6)tftp ligand is described. H(6)tftp and all intermediate molecules involved in the synthesis were fully characterized in the liquid and solid states. While the La3+-based LnOF material was isolated as single-crystals, with its crystal structure being fully described by single-crystal X-ray diffraction, phase identification of the Eu3+-and Tb3+-based materials was performed by powder X-ray diffraction. It is shown that the crystal structure of this isotypical series of materials is based on a neutral two-dimensional (2)(infinity)[Ln(H(3)tftp)(H2O)] coordination polymer placed in the ac plane of the unit cell, exhibiting a uninodal 4-connected square layered topology. It is shown that the most striking and supramolecular relevant interactions are classical O-H center dot center dot center dot O hydrogen bonds within the polymer, further contributing to the structural robustness of the layer. Prepared LnOFs were fully characterized in the solid state using elemental and thermogravimetric analysis, electron microscopy (SEM and EDS) and FT-IR spectroscopy. Compound 1 was further studied using solid-state NMR (P-31 HPDEC MAS and C-13{H-1} CP MAS) and thermodiffractometry. Photoluminescent studies have been performed on the mixed-lanthanide materials 2 and 3.

The combination of the glycine-derivative supramolecular salt 4,6-bis(carboxymethylamino)-2-oxo-2,3-dihydro-1,3,5-triazin-1-ium chloride (H(2)bodt center dot HCl) and lanthanide(III) chloride hydrates under hydrothermal conditions (120 degrees C, 48 h) led to the formation of a family of isotypical materials formulated as [Ln(bodt)(Hbodt)] [where Ln(3+) = La3+ (1), (La0.95Eu0.05)(3+) (2) and (La0.95Tb0.05)(3+) (3)]. The synthesis of the novel precursor H(2)bodt center dot HCl is detailed. The structures of H(2)bodt center dot HCl and its intermediate compound were unveiled by single-crystal X-ray diffraction and characterized by standard liquid-state techniques. The crystallographic details of compound 1 were unveiled in the monoclinic P2/c space group by using single-crystal X-ray diffraction, with the crystal structure of 1 comprising a one-dimensional (1)(infinity)[La(bodt)(Hbodt)] coordination polymer. All polymeric materials were fully characterized by FT-IR, electron microscopy (SEM and EDS), powder X-ray diffraction, and elemental and thermogravimetric analyses. The photoluminescent properties of 1 and of the mixed-lanthanide materials 2 and 3 were investigated at ambient and low temperatures. An excited-state intermolecular proton transfer (ESPT) process, induced by intermolecular hydrogen-bonding interactions, is proposed to account for the observed anomalous emission and excitation spectra of 1. Aiming at providing an in-depth understanding of the emission (fluorescence and phosphorescence) properties of the ligand, time-dependent density functional theory (TD-DFT) calculations were also performed.

The photoluminescence properties of (Gd,Yb,Tb)PO4 nanocrystals synthesized via a hydrothermal route at 150 degrees C are reported. Energy-transfer from Gd3+ to Tb3+ is witnessed by the detailed analyses of excited-state lifetimes, emission quantum yields, and emission and excitation spectra at room temperature, for Tb3+ concentrations ranging from 0.5 to 5.0 mol%. Absolute-emission quantum yields up to 42% are obtained by exciting within the (6I)7/2-17/2 (Gd3+) manifold at 272 nm. The room temperature emission spectrum is dominated by the D-5(4) -> F-7(5) (Tb3+) transition at 543 nm, with a long decay-time (3.95-6.25 ms) and exhibiting a rise-time component. The D-5(3) -> F-7(6) (Tb3+) rise-time (0.078 ms) and the P-6(7/ 2) -> S-8(7/2) (Gd3+) decay-time (0.103 ms) are of the same order, supporting the Gd3+ to Tb3+ energy-transfer process. A remarkably longer lifetime of 2.29 ms was measured at 11 K for the P-6(7/2) -> S-8(7/2) (Gd3+) emission upon excitation at 272 nm, while the emission spectrum at 11 K is dominated by the P-6(7/2) -> S-8(7/2) transition line, showing that the Gd3+ to Tb3+ energy-transfer process is mainly phonon-assisted with an efficiency of similar to 95% at room temperature. The Gd3+ to Tb3+ energy transfer is governed by the exchange mechanism with rates between 10(2) and 10(3) s(-1), depending on the energy mismatch conditions between the (6I)(7/2) and P-6(7/2) levels of Gd3+ and the Tb3+ I-5(7), F-5(2,3) and H-5(5,6,7) manifolds and the radial overlap integral values.