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Tautocrowns - new aza crown ethers with active sidearms

English title Tautocrowns - new aza crown ethers with active sidearms
Applicant Wirz Jakob
Number 110961
Funding scheme SCOPES
Research institution Physikalische Chemie Departement Chemie Universität Basel
Institution of higher education University of Basel - BS
Main discipline Physical Chemistry
Start/End 01.09.2005 - 31.12.2008
Approved amount 72'000.00
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All Disciplines (2)

Physical Chemistry
Inorganic Chemistry

Keywords (3)

molecular switches; excited state proton transfer; flash photolysis

Lay Summary (English)

Lay summary
The main goal of the project is to explore tautomerism for potential use in signal conversion. Change in a tautomeric state can be accomplished by a fast proton transfer reaction leading to a structure with different molecular properties. Switching between two tautomeric states is linked to changes in the complexation abilities of the guest-host system by modulation of the hydrogen bonding ability to the antenna. At the same time, engagement of this antenna causes a clean change in the tautomeric state. The sensitivity of the electronic ground- and excited states of the tautomeric forms to environmental stimuli (light, pH, T, solvents), and to the presence of a variety of substituents or hydrogen bonding can be exploited in the design of flexible tools for control. As a host receptor, crown ethers, calixarenes or cyclodextrines could be applied.

The successful design of such switches requires substantial and detailed knowledge about the rates of proton transfer (and especially excited state proton transfer) and about the effect of the stimuli. Compounds exhibiting excited state proton transfer (ESPT) are used as high-energy radiation detectors, as fluorescent probes, and as polymer protectors. At the same time hydrogen bonding and proton transfer reactions are two major mechanisms in biological signal processing., A detailed study on the mechanism of proton transfer will be performed. The accumulated systematic knowledge will allow us in the second stage to screen suitable tautomeric compounds for use as signal converters and to concentrate on optimizing the molecular design.

Direct link to Lay Summary Last update: 21.02.2013

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