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Highly Fluorescent (highly + fluorescent)

Distribution by Scientific Domains

Chemistry	62%

Selected Abstracts

Synthesis of Highly Fluorescent and Soluble 1,2,4-Linking Hyperbranched Poly(arylenevinylene) Featuring Intramolecular Energy Funneling

ADVANCED FUNCTIONAL MATERIALS, Issue 10 2010
Zengqi Xie
Abstract The synthesis and optical properties of a highly soluble (>200,mg,mL,1) and highly fluorescent (,F in film,=,0.64) 1,2,4-linking hyperbranched poly(arylenevinylene) (1,2,4- hb -PAV) prepared via Wittig reaction of A3 (biphenyl-tricarbaldehyde) and B2 (phosphonium salt) monomers is reported. The molecular weight of 1,2,4- hb -PAV can be precisely controlled by the amount of the base (NaOCH3) used in the polymerization. The absorption and photoluminescence (PL) spectra of 1,2,4- hb -PAV shows distinct red-shifts compared to conventional 1,3,5-linking hyperbranched poly(arylenevinylene) (1,3,5- hb -PAV), attributed to the extended ,-conjugation along ortho - (1,2-) and para - (1,4-) links. The inherent energy gradient from the shorter branches to the longer conjugated stem in 1,2,4- hb -PAV enabled a characteristic energy funneling effect, which is absent in conventional hyperbranched polymer of 1,3,5- hb -PAV. [source]

ChemInform Abstract: Synthesis and Characterization of Highly Fluorescent and Thermally Stable ,-Conjugates Involving Spiro[fluorene-9,4,-[4H]indeno[1,2-b]furan].

CHEMINFORM, Issue 30 2010
Toshiyuki Kowada
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

ChemInform Abstract: Regioselective Three-Component Synthesis of Highly Fluorescent 1,3,5-Trisubstituted Pyrazoles.

CHEMINFORM, Issue 51 2008
Benjamin Willy
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Towards Highly Fluorescent and Water-Soluble Perylene Dyes

CHEMISTRY - A EUROPEAN JOURNAL, Issue 21 2004
Christopher Kohl Dr.
Abstract A systematic approach towards highly fluorescent, water-soluble perylene-3,4:9,10-tetracarboxylic acid diimide chromophores is presented. Water solubility was introduced first through the attachment of four hydrophilic substituents onto the bay region of the perylene dye. Positively and negatively charged groups were then applied to the chromophore, and their number and their distance from the aromatic scaffold were systematically varied. To suppress aggregation, the chromophore was further isolated within a dendritic shell. Such variation of structural features and a thorough investigation of the resulting optical properties facilitated the first synthesis of perylene-3,4:9,10-tetracarboxylic acid diimides combining the properties of water solubility and fluorescence quantum yields (FQYs) close to unity, which makes them attractive as high-performance fluorescence probes in aqueous media. [source]

Highly Fluorescent Mesostructured Films that consist of Oligo(phenylenevinylene),Silica Hybrid Frameworks,

ADVANCED FUNCTIONAL MATERIALS, Issue 22 2008
Norihiro Mizoshita
Abstract Highly fluorescent and visible-light-responsive mesostructured organosilica films are successfully obtained by acidic sol,gel polycondensation of oligo(phenylenevinylene) (OPV)-bridged organosilane and tetraethoxysilane precursors in the presence of a template surfactant. The OPV-bridged organosilane precursors with different lateral alkoxy substituents, hexyloxy and 2-ethylhexyloxy, and no substituent, are synthesized by Rh-catalyzed silylation of corresponding aromatic iodides. From the organosilane precursors, three kinds of mesostructured OPV,silica hybrid films are prepared by spin-casting using evaporation-induced self-assembly. UV-vis absorption and fluorescence behavior of the OPV,silica hybrid films show that the optical properties and intermolecular interactions of the OPV moieties embedded within the organosilica frameworks strongly depend on the lateral alkoxy substituents in the precursors. The hexyloxy and 2-ethylhexyloxy substituents prevent aggregation of the OPV units in the organosilica frameworks; this result leads to high fluorescence quantum yields of 0.48,0.61 and 0.63,0.66, respectively, while non-substitution leads to lower fluorescence quantum yields of 0.25,0.34. Fluorescence decay profiles of the organosilica hybrid films also confirm a suppression of the aggregation of OPV moieties by the lateral substituents. These mesostructured organosilica films with significant optical properties in the visible-light region are promising as a new class of phosphor materials. [source]

Cover Picture: Composite Silica Spheres with Magnetic and Luminescent Functionalities (Adv. Funct.

ADVANCED FUNCTIONAL MATERIALS, Issue 4 2006
Mater.
Abstract Photographs of a colloidal dispersion of composite nanoparticles with magnetic and luminescent functionalities are shown (left, in column), which are schematically illustrated in the main image. As reported by Salgueiriño-Maceira and co-workers on p.,509, such functionalities are imparted by magnetic and semiconductor nanoparticles within a silica matrix. In the absence of a magnetic field the particles are uniformly dispersed, although they accumulate and can be dragged under the influence of a magnetic field. Their movement can be monitored by their photoluminescence. A new class of highly fluorescent, photostable, and magnetic core/shell nanoparticles in the submicrometer size range has been synthesized from a modified Stöber method combined with the layer-by-layer (LbL) assembly technique. Luminescent magnetic nanoparticles are prepared via two main steps. The first step involves controlled addition of tetraethoxysilane to a dispersion of Fe3O4/,-Fe2O3 nanoparticles, which are thereby homogeneously incorporated as cores into monodisperse silica spheres. The second step involves the LbL assembly of polyelectrolytes and luminescent CdTe quantum dots onto the surfaces of the silica-coated magnetite/maghemite particles, which are finally covered with an outer shell of silica. These spherical particles have a typical diameter of 220,±,10,nm and a saturation magnetization of 1.34,emu,g,1 at room temperature, and exhibit strong excitonic photoluminescence. Nanoparticles with such a core/shell architecture have the added benefit of providing a robust platform (the outer silica shell) for incorporating diverse functionalities into a single nanoparticle. [source]

Determining acetylcholinesterase inhibitory activity in plant extracts using a fluorimetric flow assay

PHYTOCHEMICAL ANALYSIS, Issue 3 2003
In Kyung Rhee
Abstract A fluorometric assay for acetylcholinesterase inhibitory activity was developed in a flow system using the fluorogenic substrate 7-acetoxy-1-methyl quinolinium iodide which is hydrolysed to the highly fluorescent 7-hydroxy-1-methyl quinolinium iodide. The detection limit of galanthamine is 0.5,µM, which is about 20 times more sensitive than in the colorimetric flow assay. In the presence of 30% methanol or of 5% acetonitrile, about 70% of the enzyme activity could still be detected. Various plant extracts have been screened using the described system including bulbs of Galanthus nivalis, Eucharis amazonica (E. × grandiflora), Crinum powelli and Nerine bowdenii (all members of the Amaryllidaceae), which showed strong AchE inhibitory activity. Copyright © 2003 John Wiley & Sons, Ltd. [source]