Collect. Czech. Chem. Commun. 2005, 70, 1891-1908

Luminescence of a New Ru(II) Polypyridine Complex Controlled by a Redox-Responsive Protonable Anthra[1,10]phenanthrolinequinone

František Hartla,*, Sandrine Vernierb and Peter Belserb,*

a Van't Hoff Institute for Molecular Sciences, Universiteit van Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands
b Department of Chemistry, University of Fribourg, Chemin du Musée 9, 1700 Fribourg, Switzerland


Redox-controlled luminescence quenching is presented for a new Ru(II)-bipyridine complex [Ru(bpy)2(1)]2+ where ligand 1 is an anthra[1,10]phenanthrolinequinone. The complex emits from a short-lived metal-to-ligand charge transfer, 3MLCT state (τ = 5.5 ns in deaerated acetonitrile) with a low luminescence quantum yield (5 × 10-4). The emission intensity becomes significantly enhanced when the switchable anthraquinone unit is reduced to corresponding hydroquinone. On the contrary, chemical one-electron reduction of the anthraquinone moiety to semiquinone in aprotic tetrahydrofuran results in total quenching of the emission.

Keywords: Ruthenium; Polypyridine complexes; Anthraquinone; Phenanthrolines; Bipyridines; Electron transfer; Luminescence quenching; Electrochemistry; Redox switch; UV-VIS spectroscopy; Cyclic voltammetry.

References: 24 live references.