SPECTROSCOPIC INVESTIGATION OF CHLOROPHYLL PIGMENTS IN ANHYDROUS POLYMER MATRICES

The properties of chlorophyll (Chl) a and pheophytin (Pheo) a embedded in the rigid anhydrous polymer films, polyvinyl alcohol (PVA) and nit rocellulose (NC) are reviewed. The aggregation capability of these pig ments in two matrices is characterized by absorption, fluorescence, ex citation spectra combined with fluorescence lifetime and time-resolved anisotropy. The dimer creation ability for Chl a and Pheo a is strong ly affected by the polymer system used for investigation. The Chl a an d Pheo a ability to aggregate in polymer matrices is compared. We have been looking for a good system suitable for the study of Properties o f monomeric forms when embedded in the rigid matrix on the one hand, a nd for the study of energy transfer between different forms of Chl mol ecules on the other one. Chl a, when embedded in an anhydrous PVA matr ix, is in a very stable monomeric form white Pheo a molecules in this film tend to aggregate and in the NC film they exist in the monomeric form. Thus the PVA system can be used as a model system for investigat ion of the properties of and processes between both dimeric and monome ric structures. The NC film, however, can be used as a rigid matrix wh en only the existence of monomeric forms of the pigments is required.