Light-harvesting zinc chlorin-poly(4-vinylpyridine) complexes

To investigate the potential of light-harvesting chlorin - poly(4-vinylpyridine) (P4VP) complexes for photonic applications, we prepared solid state assemblies from chlorophyll a derived Zn pyro-pheophorbide a methylester (ZnPPME) and Purpurin 18 (P18) molecules in P4VP matrix. Here, we demonstrate the use of Förster resonant energy transfer (FRET) to enhance the optical density and Stokes shift of the system. ZnPPMe and P18 were employed as donor and acceptor molecules, respectively, and the optical response of the assembly was studied using absorption and steady-state fluorescence spectroscopy. The FRET efficiency was elucidated using time-resolved fluorescence measurements and the Förster distance was calculated using the measured specroscopic data yielding a value of 42.2 Å. These preliminary results will enable the development of new biomimetic photonic materials.