Refine
Has Fulltext
- no (96) (remove)
Year of publication
Document Type
- Article (96)
Is part of the Bibliography
- yes (96)
Keywords
- Fluorescence (5)
- Anisotropy (2)
- DR-UV-Vis (2)
- Europium (2)
- Metal complexation (2)
- Raman (2)
- TRLFS (2)
- 2,10-Bis-(3-aminopropyloxy)dibenzo[aj]perylene-8,16-dione (1)
- 5-Hexadecanoylaminofluorescein (1)
- Absorption (1)
- Alumina (1)
- Antibody (1)
- Antibody binding (1)
- Aromatic compounds (1)
- Benzoic acids (1)
- Boric acid (1)
- Carboxyfluorescein (1)
- Carboxyrhodamine (1)
- Chromophores (1)
- Contact angle (1)
- DBD dye (1)
- DFT calculations (1)
- DNA (1)
- Dynamic equilibrium (1)
- Energy transfer (1)
- Energy-transfer probe (1)
- Escherichia coli (1)
- Exciplex (1)
- FLNS (1)
- FRET (1)
- Fluorescence anisotropy (1)
- Fluorescence correlation (1)
- Fluorescence correlation spectroscopy (1)
- Formation constant (1)
- Forster resonance energy transfer (FRET) (1)
- Forster resonance energy transfer (FRET) system (1)
- Forster resonance energy transfer(FRET) (1)
- Gas-sorption (1)
- Hapten (1)
- Hexadecyltrimethylammonium bromide (1)
- High-cell-density culture (1)
- Humic acid (1)
- Humic substance (1)
- Humic substances (1)
- Hydrocarbons (1)
- Infrared spectroscopy (1)
- Intramolecular deactivation (1)
- Isotope exchange (1)
- Kinetics (1)
- Lanthanide ions (1)
- Lanthanides (1)
- Ligand design (1)
- Luminescence (1)
- Magnetic properties (1)
- Metal-proton exchange reaction (1)
- Miniaturized cultivations (1)
- Model ligand (1)
- Molecular rods (1)
- Nanofibers (1)
- Near infra-red (1)
- Optical oxygen sensor (1)
- Oxygen sensing (1)
- Paratope (1)
- Perylene (1)
- Phenylacetylide (1)
- Phosphorescence lifetime (1)
- Plasmid DNA production (1)
- Poly(trimethylsilylpropyne) matrix (1)
- Polycyclic aromatic hydrocarbons (1)
- Pulsed interleaved excitation (1)
- Pyrene (1)
- Raman spectroscopy (1)
- Rare-earth elements (1)
- Reaction mechanisms (1)
- Reversibility (1)
- Ruthenium complexes (1)
- SEM (1)
- Single molecule fluorescence (1)
- Single-molecule FRET (1)
- Solid phase (1)
- Solubility (1)
- Solvothermal synthesis (1)
- Spiro compounds (1)
- Supramolecular chemistry (1)
- Surface complexes (1)
- Time-resolved spectroscopy (1)
- Transient absorption (1)
- Ultra-low (1)
- Upconversion luminescence (1)
- Vesicles (1)
- X-ray diffraction (1)
- X-ray photoelectron spectroscopy (1)
- azobenzene containing surfactants (1)
- cement admixtures (1)
- cement hydration (1)
- ceria (1)
- chromoionophore (1)
- complexes (1)
- core shell UCNP (1)
- core-shell materials (1)
- drug carrier system (1)
- energy-transfer (1)
- fluorescence anisotropy (1)
- fluorescence correlation spectroscopy (1)
- green (1)
- humic acid (1)
- immunoassay (1)
- indicators (1)
- intracellular pH indicator (1)
- ion optodes (1)
- ionophore (1)
- kinetic of cis-trans isomerization (1)
- lanthanide ions (1)
- lanthanides (1)
- luminescence (1)
- mAb (1)
- membrane (1)
- meso-tetrakisphenylporphyrins (1)
- nanocomposite (1)
- nanostructures (1)
- oxygen (1)
- pH-sensitive liposome (1)
- photoluminescence (1)
- probes (1)
- pyrochlore (1)
- rare earths (1)
- resonance energy transfer (1)
- samples (1)
- selective drug release (1)
- sensors (1)
- solid phase (1)
- solubility (1)
- storage capacity (1)
- supported catalyst (1)
- switches (1)
- systems (1)
- temperature (1)
- time-resolved fluorescence spectroscopy (1)
- time-resolved luminescence (1)
- upconversion (1)
- upconversion nanoparticles (1)
- zirconia (1)
Institute
Deuteration effects on the vibronic structure of the emission and excitation spectra of triangular [ 4] phenylene (D-3h [4]phenylene) were studied using laser-excited Shpol'skii spectroscopy (LESS) in an octane matrix at 4.2 K. For correct assignment of the vibrational modes, the experimental results were compared with calculated frequencies (B3LYP/6-31G*). CH vibrations were identified by their characteristic isotopic shifts in the spectra of deuterated triangular [4]phenylenes. Two CC stretching modes, at 100 cm(-1) and 1176 cm(-1), suitable as probes for bond strength changes in the excited state, were identified. The isotope effect on the internal conversion rates of triangular [4] phenylene was evaluated from measurements of temperature dependent lifetime. Isotope dependency and the magnitude of the internal conversion rates indicate that internal conversion in triangular [4] phenylene is most likely induced by CH vibrations. The results obtained by LESS and lifetime measurements were compared with PM3 PECI calculations of the excited state structure. The theoretical results and the relation between ground and excited state vibration energies of the 1176 cm(-1) probe vibration indicate a reduction of bond alternation of the central cyclohexatriene ring in the excited state
Time-resolved photoluminescence analysis of distribution and migration of terbium ions in zeolites X
(2004)
The photoluminescence (PL) dynamics of terbium-exchanged zeolites X was investigated upon laser excitation at 355 nm. The results evidenced the presence of at least two terbium main environments with PL lifetimes varying between 391-411 and 753-770 mus. The two-site nature of terbium distribution in zeolites X permitted a quantitative analysis of the migration process of terbium ions inside the pores and cavities upon dehydration in air at 200 degreesC. Besides the increase of the PL lifetimes with about 30% and 80% compared to those of the hydrated zeolite, a fraction of almost 30% of terbium ions was estimated to migrate from the supercages to the neighboring sodalites or hexagonal prisms. Our results evidenced for the first time the capability of time-resolved luminescence spectroscopy in quantitatively tracking for the intrazeolitic migration of lanthanides. (C) 2004 Elsevier B.V. All rights reserved
Polymer solar cell devices with nanostructured blend layers have been fabricated using single- and dual- component polymer nanospheres. Starting from an electron-donating and an electron-accepting polyfluorene derivative, PFB and F8BT, dissolved in suitable organic solvents, dispersions of solid particles with mean diameters of ca. 50 nm, containing either the pure polymer components or a mixture of PFB and F8BT in each particle, were prepared with the miniemulsion process. Photovoltaic devices based on these particles have been studied with respect to the correlation between external quantum efficiency and layer composition. It is shown that the properties of devices containing a blend of single-component PFB and F8BT particles differ significantly from those of solar cells based on blend particles, even for the same layer composition. Various factors determining the quantum efficiency in both kinds of devices are identified and discussed, taking into account the spectroscopic properties of the particles. An external quantum efficiency of ca. 4% is measured for a device made from polymer blend nanoparticles containing PFB:F8BT at a weight ratio of 1:2 in each individual nanosphere. This is among the highest values reported so far for photovoltaic cells using this material combination
Intrinsic fluorescence quenching of humic substances (HS) and the sensitization of Ln(3+) luminescence (Ln3+ Tb3+, Eu3+) in HS complexes were investigated. Both measurements yielded complementary information on the complexation of metals by HS. Large differences between fulvic acids(FA)and humic acids (HA) were found. From time-resolved luminescence measurements it is concluded that a combination of energy transfer and energy back transfer between HS and Ln(3+) is responsible for the observed luminescence decay characteristics. In the case of Eu3+, an additional participation of charge-transfer states is suggested. A new concept for the evaluation of the sensitized luminescence decays of Ln(3+) was adapted
To determine whether Forster resonance energy transfer (FRET) measurements can provide quantitative distance information in single-molecule fluorescence experiments on polypeptides, we measured FRET efficiency distributions for donor and acceptor dyes attached to the ends of freely diffusing polyproline molecules of various lengths. The observed mean FRET efficiencies agree with those determined from ensemble lifetime measurements but differ considerably from the values expected from Forster theory, with polyproline treated as a rigid rod. At donor-acceptor distances much less than the Forster radius R-o, the observed efficiencies are lower than predicted, whereas at distances comparable to and greater than R-0, they are much higher. Two possible contributions to the former are incomplete orientational averaging during the donor lifetime and, because of the large size of the dyes, breakdown of the point-dipole approximation assumed in Forster theory. End-to-end distance distributions and correlation times obtained from Langevin molecular dynamics simulations suggest that the differences for the longer polyproline peptides can be explained by chain bending, which considerably shortens the donor-acceptor distances