ROOM-TEMPERATURE TRIPLE PROTON-TRANSFER OF 7-HYDROXYQUINOLINE AND STABILIZATION OF ITS GROUND-STATE KETO TAUTOMER IN A POLYMERIC MATRIX

7-hydroxyquinoline (7HQ) dissolved in a solid poly(2-hydroxyethylmetha crylate) (PHEMA) matrix shows dual fluorescence at room temperature: a blue one (376 nm) from enol forms and a green one (515 nm) from the k eto tautomer. This isomer can be populated by an excited-state triple proton transfer in well-bridged complexes of 7HQ-PHEMA or by vertical excitation of the long-term stable keto tautomer in the ground state.