Dielectric stabilization controls excited-state proton transfer and ion pair dynamics in organic solvents.

ABSTRACT: Excited-state proton transfer (ESPT) in aprotic organic solvents has received limited attention due to their inability to accept protons. However, bimolecular ESPT from a photoacid to an organic base in such media enables systematic studies on the influence of macroscopic solvent parameters on the ESPT as demonstrated in this work. The full photocycle starting from initial deprotonation in a hydrogen-bonded donor-acceptor complex to full dissociation in the excited state followed by slow recombination in the ground state was characterized by various spectroscopic methods in solvent mixtures of varying polarity. The initial deprotonation producing contact ion pairs is ultrafast (sub-100 fs) and requires minimal solvent reorganization. The contact ion pairs dissociate via a distinct i

SUBMITTER: Raj A 

PROVIDER: S-EPMC12230855 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature