Environment-sensitive quinolone demonstrating long-lived fluorescence and unusually slow excited-state intramolecular proton transfer kinetics

0471842 - ÚOCHB 2017 RIV GB eng J - Journal Article
Zamotaiev, O. M. - Shvadchak, Volodymyr - Sych, T. P. - Melnychuk, N. A. - Yushchenko, Dmytro A. - Mely, Y. - Pivovarenko, V. G.
Environment-sensitive quinolone demonstrating long-lived fluorescence and unusually slow excited-state intramolecular proton transfer kinetics.
Methods and Applications in Fluorescence. Roč. 4, č. 3 (2016), č. článku 034004. ISSN 2050-6120. E-ISSN 2050-6120
Institutional support: RVO:61388963
Keywords : quinolone * fluorescent probes * local polarity * hydration * excited-state intramolecular proton transfer * kinetics
Subject RIV: CC - Organic Chemistry
Impact factor: 2.656, year: 2016

A new small fluorescent dye based on 3-hydroxybenzo[g]quinolone, a benzo-analogue of Pseudomonas quinolone signal species, has been synthesized. The dye demonstrates interesting optical properties, with absorption in the visible region, two band emission due to an excited-state intramolecular proton transfer (ESIPT) reaction and high fluorescence quantum yield in both protic and aprotic media. Time-resolved fluorescence spectroscopy shows that the ESIPT reaction time is unusually long (up to 8 ns), indicating that both forward and backward ESIPT reactions are very slow in comparison to other 3-hydroxyquinolones. In spite of these slow rate constants, the ESIPT reaction was found to show a reversible character as a result of the very long lifetimes of both N* and T* forms (up to 16 ns). The ESIPT reaction rate is mainly controlled by the hydrogen bond donor ability in protic solvents and the polarity in aprotic solvents. Using large unilamellar vesicles and giant unilamellar vesicles of different lipid compositions, the probe was shown to preferentially label liquid disordered phases.
Permanent Link: http://hdl.handle.net/11104/0269172