Dennis J. Salmon

Multiple emissions from charge transfer excited states of ruthenium(II)—polypyridine complexes

Abstract The complex cis-[(bpy)2Ru 2]4+ (bpy is 2,2′-bipyridine) has been prepared by methylation of (bpy)2Ru 2]2+. Electrochemical studies show that introduction of the bound pyridinium group creates a chemically attached electron acceptor site (E1/2 = −0.76 V in 0.1 M [N(n-C4H9)4]PF6-acetonitrile versus the SSCE). Evidence for a low-lying dπ — π* charge transfer (CT) state has been obtained by the appearance of a low energy emission at λmax 680 nm in ecetonitrile (τ0 = 104 ns) and for an upper dπ — π* (bpy) state by a higher energy emission at 580 nm in a methanol glass at 77 K (τ0 = 7.59 μs). Both emissions appear in a water—ethylene glycol solution containing 5% by weight polyvinyl alcohol at room temperature.

SYNTHESIS AND PROPERTIES OF THE CHLORO-BRIDGED DIMER ((BPY)2RUCL)22+ AND ITS TRANSIENT 3+ MIXED-VALENCE ION

Das Ru(II)-Titeldimere (II) ist durch Behandlung des Chloronitrosyl-Ru(III)-Komplexes (I) mit methanolischem K-azid als Hexafluorophosphat erhaltlich.