Laser induced fluorescence spectroscopy of jet cooled trans 1-methoxynaphthalene: A comparative study with trans 1-hydroxynapthalene

Fluorescence excitation (FE) and dispersed fluorescence (DF) spectra for S1 ↔ S0 transitions of 1-methoxynaphthalene have been studied in a supersonic free jet expansion. Vibronic bands corresponding to only one isomer dominate the FE spectrum, and by theoretical calculation we have assigned the species to the minimum energy trans-conformer. Complete assignment of the vibronic bands displayed in the DF spectrum measured following excitation of the 0 0 0 origin has been suggested. The DF spectra of other vibronic bands show signatures of extensive vibronic mode mixing in the S1 state. The measured spectral features have been compared to 1-hydroxynaphthalene and assignments suggested in earlier studies for the vibronic bands in the DF spectrum have been reviewed.