| Autor: |
L. K. Patterson, Oded Gonen, Haim Levanon |
| Rok vydání: |
1981 |
| Předmět: |
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| Zdroj: |
Israel Journal of Chemistry. 21:271-276 |
| ISSN: |
0021-2148 |
| DOI: |
10.1002/ijch.198100050 |
| Popis: |
The fluorescence and force-area behavior of chlorophyll a (Chl a) monomolecular films diluted with hydrocarbon on an aqueous subphase is reported. It is found that the diluent hexadecane, instead of conventional fatty alcohols, results in a substantial increase in the fluorescence yield of Chl a. The luminescence intensity varies nonmonotonically with respect to the intermolecular distance. A model for the mutual orientation of the chlorophyll pigments and the consequent energy transfer processes in terms of a Forster mechanism is proposed. For a random distribution of the Chl a molecules in the monolayer (k2 = 2/3) an average value of 43° is calculated for the angle between the molecular planes and the water surface. This model yields a value of 23 A for the Forster R0. Also, a value of 58° is derived for the angle between the Q-band transition moment and the line of intersection between the molecular plane and water surface. When a mixture of Chl a and Chl b in the monolayers is being excited at the absorption band of the latter pigment, typical fluorescence of Chl a is being detected. This sensitization process can also be interpreted in terms of the orientational model of the Chl molecules as presented in this work. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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