Dataset Information

Photoinduced signal amplification through controlled externally sensitized fragmentation in masked sensitizers.

ABSTRACT: Addition of lithiated dithianes to diaryl ketones, potential electron-transfer sensitizers, disrupts conjugation between the two aromatic moieties, effectively masking the sensitizer. A novel photoamplification strategy is developed based on photosensitized cleavage in such adducts, where each fragmentation event releases more diaryl ketone, capable of sensitization. As a result, mass release of dithianes, triggered with a very small amount of the initiator, is observed. Such amplified release can be made contingent on a molecular recognition event, offering a promising methodology for high throughput bioanalytical applications. The concept is proved with the use of micro- and nanosized polymeric supports, including dendrimers.

SUBMITTER: Kottani R

PROVIDER: S-EPMC2519093 | biostudies-literature | 2006 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Photoinduced signal amplification through controlled externally sensitized fragmentation in masked sensitizers.

Kottani Rudresha R Majjigapu Janaki R R JR Kurchan Alexei A Majjigapu Kavitha K Gustafson Tiffany P TP Kutateladze Andrei G AG

Journal of the American Chemical Society 20061101 46

Addition of lithiated dithianes to diaryl ketones, potential electron-transfer sensitizers, disrupts conjugation between the two aromatic moieties, effectively masking the sensitizer. A novel photoamplification strategy is developed based on photosensitized cleavage in such adducts, where each fragmentation event releases more diaryl ketone, capable of sensitization. As a result, mass release of dithianes, triggered with a very small amount of the initiator, is observed. Such amplified release c ...[more]

PMID: 17105275

Similar Datasets

Project description:Six new bio-inspired flavylium salts were synthesized and investigated by a combined computational and experimental study for dye-sensitized solar cell applications. The compounds were characterized by FT-IR, UV-Vis, NMR spectroscopy, and LC-MS spectrometry techniques. The pH-dependent photochromic properties of the flavylium dyes were investigated through a UV-Vis spectroscopy study and revealed that they follow the same network of chemical reactions as anthocyanins upon pH changes. The structural and electronic properties of the dyes were investigated using density functional theory (DFT) and time-dependent density functional theory (TD-DFT). Geometry optimization calculation revealed that all dyes, regardless of the specie, flavylium cations or quinoidal bases, present a planar geometry. The photovoltaic performances of the dyes, in both flavylium and quinoidal base forms, were evaluated by the HOMO and LUMO energies and by calculating the light-harvesting efficiencies, the free energy change of electron injection, and the free energy change regeneration. The MO analysis showed that all dyes can inject electrons into the conduction band of the TiO2 upon excitation and that the redox couple can regenerate the oxidized dyes. The results obtained for the free energy change of electron injection suggest that the quinoidal bases should inject electrons into the semiconductor more efficiently than the flavylium cations. The values for the free energy change regeneration showed that the redox electrolyte can easily regenerate all dyes. Dipole moment analysis was also performed. DSSCs based on the dyes, in both flavylium and quinoidal base forms, were assembled, and their photovoltaic performances were evaluated by measuring the open-circuit voltage, the short circuit current density, the fill factor, and the energy conversion efficiency. Results obtained by both experimental and computational studies showed that the overall performances of the DSSCs with the quinoidal forms were better than those obtained with the flavylium cations dyes.

Dataset Information

Photoinduced signal amplification through controlled externally sensitized fragmentation in masked sensitizers.

Publications

Photoinduced signal amplification through controlled externally sensitized fragmentation in masked sensitizers.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets