Efficient, long-range energy migration in Ru^II polypyridyl derivatized polystyrenes in rigid media. Antennae for artificial photosynthesis

Results of CW and lifetime emission studies have been used to demonstrate facile intra-strand energy transfer in the derivatized polystyrene polymer [PS-4-CH₂CH₂NHC(O)-(Ru^II(4,4′-(CONEt₂)₂bpy)₂)₁₇(Os^II(bpy)₂))₃](PF₆)₄₀ in four rigid media: frozen 5:4 (v:v) propionitrile:butyronitrile solutions at 77 K, polymethyl-methacrylate (PMMA) and polyethylene glycol-dimethacrylate (PEG-DMA) films, and silica xerogel monoliths at room temperature. Continued rapid energy transfer in rigid media is in contrast to electron transfer which is inhibited. This can be explained by energy transfer theory and is due to a decrease in the energy transfer barrier because of the frozen nature of the medium. The abbreviation used for the polymer defines the chemical link to the polystyrene backbone and gives the extent of loading out of 20 available sites.