Intermolecular Quenching of Higher Excited States

Abstract

The influence of β carotene on the fluorescence yield of chlorophyll a in 3-methoxy- 1-butanol is investigated. β carotene does not affect the fluorescence yield when chlorophyll a is excited in the red absorption band at 660 nm. However, a quenching of the red fluorescence of chlorophyll a is observed when excited at 415 nm. This is suggested to be due to a quenching of the second excited state of chlorophyll a by β carotene.