Fluorescence and phosphorescence of 9-hydroxyphenalenone in solid neon and its hydrogen tunneling potential function

Abstract

Absorption and emission spectra of 9-hydroxyphenalenone in solid neon have been studied. Vibrational relaxation in the first excited singlet state is shown to be relatively slow and extensive unrelaxed fluorescence is observed. Analysis of the spectra yields information about the magnitude of the tunneling splitting in the double minimum potential both for normal (Δ″H=69 cm−1) and deuterated (Δ■D=12 cm−1) 9-hydroxyphenalenone. The upper state values are 311 and 172 cm−1, respectively. A long lived (τ∼25 ms) phosphorescence with origin near 17 350 cm−1 is also observed.