Abstract
It was found that cations formed by the protonation of 2-amino-3-(2'-benzoxazolyl)-quinoline (ABO) and 2-amino-3-(2'-benzothiazolyl)-quinoline (ABT) at the nitrogen atom of the quinoline ring exhibit excited-state intramolecular proton transfer (ESIPT). The two-band fluorescence of these cations is due to the emission from two species: the initial tautomer (short-wavelength band) and the ESIPT product (long-wavelength band). The relative intensity of the long-wavelength band depends on the basicity of the proton-accepting moiety and temperature. Quantum-chemical calculations demonstrated that ESIPT in cations involves overcoming a significant potential barrier, which increases with the decreasing basicity of the proton-accepting benzazole moiety. Using femtosecond absorption spectroscopy and nanosecond fluorescence spectroscopy, the effective ESIPT time in the studied cations was determined, which increased with decreasing temperature.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
