Quenching of aromatic hydrocarbon fluorescence and aryl ketone phosphorescence by alkyl disulfides has been investigated. Two quenching mechanisms, charge-transfer stabilized exciplex formation and electronic energy transfer, have been considered. Charge transfer appears to be unimportant for the aromatic hydrocarbons and ketones studied. Endothermic singlet-singlet energy transfer is more efficient than predicted by the Arrhenius equation. Excitation of vibrationally excited ground-state disulfide molecules provides a possible explanation for efficient endothermic quenching. Low-temperature uv spectroscopy indicates that the long-wavelength absorption of disulfides consists predominately of hot-band transitions.
ASJC Scopus subject areas
- Colloid and Surface Chemistry