Zinc(II) and ruthenium(II) complexes of novel fluorene substituted terpyridine ligands: Synthesis, spectroscopy and electrochemistry

Terpyridine ligands substituted with fluorene, fluorenylethynylthiophene and fluorenylethynyl benzene were obtained by applying Krohnke synthesis and Sonogashira coupling reactions. [ZnL2](2+) and [Ru(L)- (tpy)](2+) complexes were obtained by standard methods and characterized by spectroscopic and electrochemical methods. Zinc complexes are bright luminophores emitting blue to yellow colors depending on the nature of the conjugation in the ligand, while the ruthenium complexes do not emit at room temperature. The high quantum yields and short lifetimes indicate that the emission in the zinc complexes is mainly ligand centered.