Direct Observation of Temperature dependent Excited-state Equilibrium in Dinuclear Ruthenium Terpyridine Complexes Bearing Electron-poor Bridging Ligands
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Siebert, Ronald; Hunger, Christoph; Guthmuller, Julien; Schluetter, Florian; Winter, Andreas; Schubert, Ulrich S.; González, Leticia; Dietzek, Benjamin; J\", ; urgen Popp,
- Abstract:
- Dinuclear rutheniumterpyridine complexes, bearing highly
conjugated bridging ligands, have been investigated by time- and temperature-
dependent emission spectroscopy, femtosecond time-resolved transient-
absorption spectroscopy, and time-dependent density functional theory
calculations. These terpyridine compounds show room-temperature emission
around 640 nm and lifetimes between 140 and 230 ns. Reduction of the
temperature results in an overall increase of emission lifetime. However, the
specific temperature dependence of the luminescence lifetime depends on
the particular bridging ligand. This ligand-specific behavior is found to
correlate with the electronic structure of the ligand, which indicates an
excited-state equilibrium between a highly delocalized 3MLCT and a ligandcentered
3ππ* excited-state. Due to this equilibrium a prolonged roomtemperature
lifetime is observed.
- Year:
- 2011
- Type of Publication:
- Article
- Journal:
- Journal of Physical Chemistry
- Volume:
- 115
- Pages:
- 12677 - 12688