2024-03-042024-03-042021COCCA, Leandro Henrique Zucolotto et al. Two-photon brightness of highly fluorescent imidazopyridine derivatives: two-photon and ultrafast transient absorption studies. Journal of Molecular Liquids, Amsterdam, v. 248, e118379, 2021. DOI: 10.1016/j.molliq.2021.118379. Disponível em: https://www.sciencedirect.com/science/article/pii/S0167732221031044. Acesso em: 29 fev. 2024.0167-7322e- 1873-3166https://www.sciencedirect.com/science/article/pii/S0167732221031044Imidazopyridine derivatives are unnatural purines isosteres and have been idealized and synthesized in the last decades, given their great applicability in several science areas. For instance, they may present potential to be used as fluorescent bioprobes on DNA or RNA spectroscopic studies. Furthermore, their synthesis can be performed to incorporate different peripheral structures in the central imidazopyridine scaffold, modeling and increasing the optical properties. Aiming applications as fluorescent probes as molecular liquids at the therapeutic window, thanks to the considerable emissive characteristics of this class of compound, optical spectroscopic studies considering nonlinear optical properties were performed on two distinct classes of N3-MEM-3H-imidazo[4,5-b]pyridine derivatives. The presented results exposed exceptionally high fluorescence quantum yields and two-photon absorption effects at the therapeutic window. The two-photon absorption spectra revealed a particular contribution of a higher excited state in some imidazopyridine derivatives containing naphthalene group. The excited state was confirmed by femtosecond time resolved spectroscopy. The obtained two-photon brightness shows substantial values for all compounds, with the potential to be used as fluorescent probes induced by two-photon excitation.engAcesso RestritoImidazopyridinesFluorescent molecular liquids probesNonlinear opticsFemtosecond time resolved spectroscopyTwo-photon absorptionUltrafast transient absorptionTwo-photon brightnessArtigo10.1016/j.molliq.2021.118379