Optically detected zero field magnetic resonance studies of the photoexcited triplet states of chlorophyll a and b

摘要

The zerohyphen;field EPR transitions for the triplet states of chlorophyll a and chlorophyll b innhyphen;octane solutions at 2deg;K have been observed by optical detection methods. Both triplet absorption detection of magnetic resonance and fluorescencehyphen;microwave double resonance techniques were used. Sharphyphen;line (5ndash;20 MHz) zerohyphen;field EPR spectra were recorded for both molecules. The rates of depopulation for the individual triplet state spin sublevels were determined by microwavehyphen;modulated fluorescence intensity measurements. These experiments show that the middle spin sublevel is the most active in triplet state intersystem crossing for both chlorophyll a and chlorophyll b.