Ru(II)- polypyridine photosensitizer arrays
Our studies aim at understanding excited state dynamics and at controlling electron and energy transfer properties in assemblies based on this important class of photosensitizers.
- We presented the first Ru-polypyridine complex, [Ru(dqp)2]2+ that combines the favorable geometry for isomer-free, rod-like molecular arrays found in Ru(tpy)2-analogs, with a long excited state lifetime (3 us). (M. Abrahamsson et al. J. Am. Chem. Soc. (2006) 128, 12616-12617; J. Am. Chem. Soc (2008) 130, 15533-15542)
- We constructed the first donor-acceptor triad based on [Ru(dqp)2]2+, which displayed well-defined vectorial charge separation in very high yield (ca 95%). (R.J. Kumar, S. Karlsson et al. Chem. Eur. J. (2010) 16, 2830-2842)
- We showed that the excited MLCT state in [Ru(bpy)3]2+ is randomly distributed over all three degenerate Ru-bpy CT states in less than 500 fs. This suggests that inter-ligand electron transfer is much faster than previously believed and may not be limiting factor in electron transfer to acceptors linke dto one of the ligands. (S. Wallin et al. J. Phys. Chem. A (2005), 109, 4697-4704)