title: Expanding the coordination cage: a ruthenium(II)-polypyridine complex exhibiting high quantum yields under ambient conditions.
abstract: A mononuclear ruthenium(II) polypyridyl complex with an enlarged terpyridyl coordination cage was synthesized by the formal introduction of a carbon bridge between the coordinating pyridine rings. Structurally, the ruthenium(II) complex shows an almost perfect octahedral N6 coordination around the central Ru(II) metal ion. The investigation of the photophysical properties reveals a triplet metal-to-ligand charge transfer emission with an unprecedented quantum yield of 13% and a lifetime of 1.36 mus at room temperature and in the presence of air oxygen. An exceptional small energy gap between light absorption and light emission, or Stokes shift, was detected. Additionally, time-dependent density functional theory calculations were carried out in order to characterize the ground state and both the singlet and triplet excited states. The exceptional properties of the new compound open the perspective of exploiting terpyridyl-like ruthenium complexes in photochemical devices under ambient conditions.
authors.affiliation: Institute of Nanotechnology, Forschungszentrum Karlsruhe, Karlsruhe, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Schramm
authors.forename: Velimir
authors.initials: V
authors.lastname: Meded
authors.forename: Heike
authors.initials: H
authors.lastname: Fliegl
authors.forename: Karin
authors.initials: K
authors.lastname: Fink
authors.forename: Olaf
authors.initials: O
authors.lastname: Fuhr
authors.forename: Zhirong
authors.initials: Z
authors.lastname: Qu
authors.forename: Wim
authors.initials: W
authors.lastname: Klopper
authors.forename: Stephen
authors.initials: S
authors.lastname: Finn
authors.forename: Tia E
authors.initials: TE
authors.lastname: Keyes
authors.forename: Mario
authors.initials: M
authors.lastname: Ruben