Chiral lanthanide complexes: coordination chemistry and applications

Self-assembly of Yttrium-containing lacunary polyoxotungstate macroanions in solution with controllable supramolecular structure size by pH or solvent content

The self-assembly and the formation of "Blackberry" type supramolecular structures for a type of Yttrium-containing polyoxometalate (K 15Na 6(H 3O) 9[(PY 2W 10O 38) 4(W 3O 14)].9H 2O, or {P 4Y 8W 43}) macroanions is characterized by using static and dynamic light scattering techniques. {P 4Y 8W 43} macroions are found to form hollow, spherical, single-layer "blackberry" structures in water and water-acetone mixed solvents. Very interestingly, the blackberry size can be accurately controlled by either changing acetone content in water-acetone mixed solvents, or by changing solution pH in aqueous solution. The blackberry size increases with decreasing pH (lower charge density) or higher acetone content in the mixed solvent (lower dielectric constant) and the blackberry size can change in responding to the change of external conditions. This indicates that the {P 4Y 8W 43} macroanions possess the properties of both "strong electrolyte type" and "weak electrolyte type" macroions, as we outlined previously. This is due to the special chemical feature of such clusters, which can be treated as Na 2HPO 4-type electrolytes in solution. The kinetics of the blackberry formation can be controlled by temperature.

Functionalized europium nanorods for in vitro imaging

Emissive europium hydroxide nanorods (ENR) (20 nm x 500 nm) functionalized by a surface coating of chromophore-containing organically modified silicate (ORMOSIL) layer, have been synthesized and characterized by high-resolution transmission electron microscopy (TEM). Low-temperature photophysical characterization of the functionalized nanorods (FENR) demonstrated a strong red 5D0 luminescence both in solid and in suspended solutions. Potentials of this nanorod material for live cell imaging have also been explored. Both the bare and functionalized nanorods are able to enter living human cells with no discernible cytotoxicity. Chromophore-to-Eu3+ energy-transfer in the functionalized nanorods enables staining of the cytoplasm of living human cells. This is confirmed by costaining with fluorescent dextran. The red chromophore-sensitized luminescence from the internalized nanorods in live human lung carcinoma cells (A549) can be observed by confocal microscopy 2 h after loading and reaches maximal emission after 24 h.

Two-photon-excited luminescence in a Tb3+ -doped lithium niobate crystal pumped by a near-infrared femtosecond laser

Blue (487.6 nm), green (544.1 nm), yellow (582.1 nm), and red (623.6 nm) upconversion (UC) luminescences are achieved in a Tb(3+)-doped lithium niobate crystal when an 800 nm femtosecond laser is loosely focused onto the sample at room temperature. The relationship between UC luminescence intensity and the pump energy indicates that a two-photon excitation process is dominant in this UC luminescence phenomenon. The Tb(3+) sensitive temperature dependence of the luminescence intensity is demonstrated via an obvious reduction of luminescence intensity with durative laser irradiation.