On the fluorescence spectrum and decay time of naphthalene

The effect of temperature, solvent, concentration of solute and quenching by oxygen on the decay time and fluorescence spectrum of naphthalene was investigated. At high solute concentrations (>0·1 M) an anomaly in the emission spectrum is interpreted as being due to transient dimers, whereas at lower solute concentrations (<0·1 M), no evidence has been found to support the assumption of transient dimers. The decay time of naphthalene in paraffin oil when excited by a pulsed beam of electrons is unaccountably longer than that of naphthalene in a less viscous medium.