Light harvesting polymers featuring non-conjugated polystyrene or p-conjugated polyfluorene backbones functionalized with Ru-polypyridyl metal complex chromophores have been constructed. The metal complex units are attached to the polymer backbone by using an azide-alkyne �click� reaction. The dynamics of energy transfer and charge transfer in these functional polymers have been explored in solution and at TiO2 interfaces by using emission and time-resolved absorption spectroscopy. The results clearly reveal that energy transfer occurs within the polymer assemblies on timescales that depend on the mechanisms. For example, in all of the polymers, energy transfer among the pendant Ru-polypyridyl complexes occurs on the nanosecond timescale via Dexter hopping. By contrast, transfer from the p-conjugated polyfluorene backbone to the pendant Ru chromophores occurs within a few picoseconds via Forster coupling. The light harvesting polymers can be adsorbed onto mesoporous TiO2 and give rise to moderately efficient photocurrent generation. Time resolved spectroscopy reveals clear evidence of the light harvesting effect for the surface adsorbed polymers, with charge injection occurring on timescales ranging from a few picoseconds to 100 nanoseconds.

Light harvesting polymers for energy conversion and solar fuels

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.