RT Journal Article
T1 Photoinduced Proton and Charge Transfer in 2‑(2′- Hydroxyphenyl)imidazo[4,5‑b]pyridine
A1 Brenlla, Alfonso
A1 Veiga Gutiérrez, Manoel
A1 Pérez Lustres, José Luis
A1 Ríos Rodríguez, María del Carmen
A1 Rodríguez-Prieto, Flor
A1 Mosquera González, Manuel
AB This paper deals with the interplay between solvent properties and isomerism of 2-(2′-hydroxyphenyl)imidazo[4,5-b]pyridine (1), and the proton and charge-transfer processes that the different isomers undergo in the first-excited singlet state. We demonstrate the strong influence of these processes on the fluorescence properties of 1. We studied the behavior of 1 in several neutral and acidified solvents, by UV–vis absorption spectroscopy and by steady-state and time-resolved fluorescence spectroscopy. The fluorescence of 1 showed a strong sensitivity to the environment. This behavior is the result of conformational and isomeric equilibria and the completely different excited-state behavior of the isomers. For both neutral and cationic 1, isomers with intramolecular hydrogen bond between the hydroxyl group and the benzimidazole N undergo an ultrafast excited-state intramolecular proton transfer (ESIPT), yielding tautomeric species with very large Stokes shift. For both neutral and cationic 1, isomers with the OH group hydrogen-bonded to the solvent behave as strong photoacids, dissociating in the excited state in solvents with basic character. The pyridine nitrogen exhibits photobase character, protonating in the excited state even in some neutral solvents. An efficient radiationless deactivation channel of several species was detected, which we attributed to a twisted intramolecular charge-transfer (TICT) process, facilitated by deprotonation of the hydroxyl group and protonation of the pyridine nitrogen
PB American Chemical Society
SN 1520-6106
YR 2013
FD 2013
LK http://hdl.handle.net/10347/17049
UL http://hdl.handle.net/10347/17049
LA eng
NO Brenlla, A., Veiga, M., Pérez Lustres, J., Ríos Rodríguez, M., Rodríguez-Prieto, F., & Mosquera, M. (2013). Photoinduced Proton and Charge Transfer in 2-(2′-Hydroxyphenyl)imidazo[4,5-b]pyridine. The Journal Of Physical Chemistry B, 117(3), 884-896. doi: 10.1021/jp311709c
NO This is the peer-reviewed version of the following article:The Journal of Physical Chemistry B 2013, 117, 884–896, DOI: 10.1021/jp311709c, which has been published in final form at https://pubs.acs.org/doi/abs/10.1021/jp311709c.This article may be used for non-commercial purposes only
NO This work has been supported by the Spanish Government and the European Regional Development Fund (Grant CTQ2010-17835) and the Xunta de Galicia (Grant CN 2012/314). A.B., M.V., and J.L.P.L. are thankful for a “Fundación Segundo Gil  Dávila” fellowship, a MEC-FPU fellowship, and a “Ramon y Cajal” contract, respectively
DS Minerva
RD 26 abr 2026