Excited-State Double Proton Transfer in 1-Azacarbazole Hydrogen Bonded Complexes
Journal
Journal of the Chinese Chemical Society
Journal Volume
43
Journal Issue
6
Pages
463-472
Date Issued
1996
Author(s)
Abstract
Abstract Excited‐state double proton transfer (ESDPT) has been studied in a variety of 1‐azacarbazole (1AC) hosted hydrogen‐bonded complexes. In 1 AC/carboxylic acids hydrogen bonded complexes, large association constants of > 1.0 × 10 4 M −1 are measured in the ground state and the rate of ESDPT is » 5.0 × 10 9 s −1 , resulting in a dominant proton‐transfer tautomer emission. In several 1 AC/lactam hydrogen bonded complexes, however, spectral and dynamic results show the existence of a fast excited‐state equilibrium between normal and proton‐transfer tautomer states. The result can be tentatively rationalized by a non‐catalytic ESDPT mechanism incorporating tautomerization energy of the guest molecule.
SDGs
Type
journal article