Vibronic spectra of radical cations of some hydroxyl substituted naphthalenes

Abstract

The fluorescence spectra of radical cations of some hydroxyl substituted naphthalenes have been investigated in boric acid glass. The emission spectra are found to have one intense band along with some weaker bands/shoulders. It is found that the shift of weaker bands/shoulders from the main band depends on the nature and position of the substituent. These frequency shifts from the main intense band are related to the vibrational frequencies of the cations in the ground state. Further, it is observed that the shift of the vibronic bands is much smaller. When two -OH substituent groups are located at neighbouring sites. This has been interpreted as an evidence for the existence of intramolecular hydrogen bonding.