The influence of H-bond geometry on the dynamics of excited state intramolecular proton transfer (ESIPT) and photoinduced tautomerization in a series of phenol-quinoline compounds is investigated. Control over the proton donor-acceptor distance (dDA) and dihedral angle between the proton donor-acceptor subunits is achieved by introducing methylene backbone straps of increasing lengths to link the phenol and quinoline. We demonstrate that a long dDA correlates with a higher barrier for ESIPT, while a large dihedral angle opens highly efficient deactivation channels after ESIPT, preventing the formation of the fully relaxed tautomer photoproduct.
- excited state
- hydrogen bonds
- intramolecular proton transfer
ASJC Scopus subject areas
- Organic Chemistry