| Popis: |
The relative fluorescence yield, the lifetime and the triplet yield have been investigated, for solutions in lecithin, of chlorophyll α in the presence of a series of quinones. The singlet and triplet yields show the same dependence on quinone concentration; the lifetimes show a slightly weaker dependence. I t is proposed that the quenching proceeds via electron transfer from the excited singlet state of the chlorophyll α molecule to its nearest neighbour quinone. A model, based upon a random distribution of molecules, is used to derive quenching parameters. The model gives a good account of the experimental data and it is found that the quenching ability is directly related to the oxidation potential of the quinone. |
