472 research outputs found
Cascading of Molecular Logic Gates for Advanced Functions: A Self-Reporting, Activatable Photosensitizer
Cataloged from PDF version of article.Logical progress: Independent molecular logic gates have been designed and characterized. Then, the individual molecular logic gates were coerced to work together within a micelle. Information relay between the two logic gates was achieved through the intermediacy of singlet oxygen. Working together, these concatenated logic gates result in a self-reporting and activatable photosensitizer. GSH=glutathione
Selective photosensitization through an and logic response: Optimization of the pH and glutathione response of activatable photosensitizers
A series of pH and GSH responsive photosensitizers were designed and synthesized. pKa values were optimized by adjusting the inductive contribution of substituents to reach a pH range (6.0-7.4) relevant to the tumour microenvironment. pH-Activatable behaviour and redox mediated release of the quencher from the PS by GSH allow the construction of an AND logic operator for selective photodynamic action in aqueous solutions. © The Royal Society of Chemistry 2015
Proof of principle for a molecular 1:2 demultiplexer to function as an autonomously switching theranostic device
Cataloged from PDF version of article.Guided by the digital design concepts, we synthesized a two-module molecular demultiplexer (DEMUX) where the output is switched between emission at near IR, and cytotoxic singlet oxygen, with light at 625 nm as the input (I), and acid as the control (c). In the neutral form, the compound fluoresces brightly under excitation at 625 nm, however, acid addition moves the absorption bands of the two modules in opposite directions, resulting in an effective reversal of excitation energy transfer direction, with a concomitant upsurge of singlet oxygen generation and decrease in emission intensity
Toward singlet oxygen delivery at a measured rate: A self-reporting photosensitizer
A Bodipy-based energy transfer cassette with a singlet oxygen reactive linker between the donor and acceptor modules has an interesting emergent property, if the acceptor module is also a photosensitizer. Singlet oxygen produced by the photosensitizer reacts rapidly with the molecule itself to liberate the energy donor, resulting in an enhanced fluorescence emission. The result is a self-reporting photosensitizer providing an assessment of the singlet oxygen production rate under the operational conditions. © 2014 American Chemical Society
Proof of principle for a molecular 1 : 2 demultiplexer to function as an autonomously switching theranostic device
Guided by the digital design concepts, we synthesized a two-module molecular demultiplexer (DEMUX) where the output is switched between emission at near IR, and cytotoxic singlet oxygen, with light at 625 nm as the input (I), and acid as the control (c). In the neutral form, the compound fluoresces brightly under excitation at 625 nm, however, acid addition moves the absorption bands of the two modules in opposite directions, resulting in an effective reversal of excitation energy transfer direction, with a concomitant upsurge of singlet oxygen generation and decrease in emission intensity. © The Royal Society of Chemistry 2013
Towards unimolecular luminescent solar concentrators: bodipy-based dendritic energy-transfer cascade with panchromatic absorption and monochromatized emission
Cataloged from PDF version of article.Ein in ein Polymer eingebetteter, panchromatischer Bodipy-Absorber mit eingebautem Energiegradienten konzentriert einfallende Sonnenstrahlung an einem endständigen Chromophor und erzeugt so eine monochromatische Emission an den Seiten des Polymer-Wellenleiters (siehe Bild). Dieses besondere Design minimiert Selbstabsorptionsverluste der peripheren Antennen-Einheiten mit einem beeindruckenden S-Faktor von 10 000
Near-IR-Triggered, Remote-Controlled Release of Metal Ions: A Novel Strategy for Caged Ions
Cataloged from PDF version of article.A ligand incorporating a dithioethenyl moiety is cleaved into fragments which have a lower metal-ion affinity upon irradiation with low-energy red/near-IR light. The cleavage is a result of singlet oxygen generation which occurs on excitation of the photosensitizer modules. The method has many tunable factors that could make it a satisfactory caging strategy for metal ions
Towards unimolecular luminescent solar concentrators: Bodipy-based dendritic energy-transfer cascade with panchromatic absorption and monochromatized emission
A polymer-embedded dendritic, bodipy-based panchromatic absorber with a built-in energy gradient concentrates incident solar radiation at a terminal chromophore, resulting in a monochromatized emission directed to the sides of the polymer waveguide (see picture). This particular design minimizes self-absorption losses from the peripheral antenna units with an impressive S factor of 10 000. © 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Coupling of the decarboxylation of 2-Cyano-2-phenylpropanoic Acid to large-amplitude motions: A convenient fuel for an Acid-Base-Operated molecular switch
The decarboxylation of 2-cyano-2-phenylpropanoic acid is fast and quantitative when carried out in the presence of 1 molar equivalent of a [2]catenane composed of two identical macrocycles incorporating a 1,10-phenanthroline unit in their backbone. When decarboxylation is over, all of the catenane molecules have experienced large-amplitude motions from neutral to protonated catenane, and back again to the neutral form, so that they are ready to perform another cycle. This study provides the first example of the cyclic operation of a molecular switch at the sole expenses of the energy supplied by the substrate undergoing chemical transformation, without recourse to additional stimuli
Coupling of the Decarboxylation of 2-Cyano-2-phenylpropanoic Acid to Large-Amplitude Motions: A Convenient Fuel for an Acid-Base-Operated Molecular Switch
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