Fine-Tuning the Electronic Properties of Binuclear Bis(terpyridyl)ruthenium(II) Complexes

Vastly improved photophysical properties of terminal Ru^II terpyridine-based chromophores is achieved by insertion of an ethynylene group between the terpyridine ligand and a covalently linked aromatic nucleus. In the case where the aromatic nucleus possesses vacant coordination sites, as shown in 1 , complexation of certain cations (e. g., Zn²⁺, Cd²⁺, or Ba²⁺) at the central unit gives a further improvement in the photoproperties due to a better blending of the respective LUMO levels.