Excited singlet state absorption spectra and relaxation kinetics of the azanaphthalenes

Publisher Website
Google Scholar
Abstract
Picosecond excited-state singlet–singlet absorption spectra (Sn ← S1) and excited-state decay kinetics are reported for several diazanaphthalenes and a triazanaphthalene in room temperature solution. New Sn (1nπ*) state energies are obtained empirically from these spectra. INDO-PSDCI molecular orbital calculations are used to confirm the Sn ← S1 nature of the excited state transitions observed. Decay rates are calculated from models based on a semiempirical molecular orbital formalism, and these calculated rates are compared with the observed ones. Agreement of the calculated and observed rates are good except in cases of substantial nπ*–ππ* mixing of the actual excited states and in a particular case of high molecular symmetry (1,5-naphthyridine).