Dual Emission from Highly Conjugated 2,2':6':2''-Terpyridine Complexes - A Potential Route to White Emitters
-
Siebert, Ronald; Winter, Andreas; Dietzek, Benjamin; Schubert, Ulrich S.; J\", ; urgen Popp,
- Abstract:
- Here, we present a new class of terpyridine complexes of the transition-metal ions, iron(II),
ruthenium(II), and osmium(II), overcoming the poor emission properties typical for this class
of polypyridyl complexes. These complexes show, besides an increased room-temperature
emission quantum yield and a prolonged lifetime of the metal-to-ligand charge-transfer
(MLCT) states, dual emission from two well-separated excited states of the same molecule.
These experimental findings are attributed to a highly stabilized ligand chromophore, where
photoinduced excited-state planarization causes an enhancement of electron delocalization.
This planarization, in turn, reduces the potential energy of the S1 state and minimizes
electronic coupling to the MLCT state, which
is prone to non-radiative deactivation via
metal-centered excited states. Due to their dual
emission the complexes presented here show
emission covering the entire Vis spectral range
upon excitation of the pp states in the near UV.
Thus, by structurally tuning the electronic
coupling of the pp and the MLCT states a
new synthetic route toward white emitters,
which can subsequently be incorporated into
polymers, is opened.
- Year:
- 2010
- Type of Publication:
- Article
- Journal:
- Macromolecular Rapid Communications
- Volume:
- 31
- Pages:
- 883 - 888