Luminescence quenching of the tris(2,2'-bipyrazine)ruthenium(II) cation and its monoprotonated complex

Abstract

The MLCT (Metal to Ligand Charge Transfer) excited state of the Ru(bipyrazine)3(2+) is quenched by a series of organic amines and methoxybenzenes, in acetontrile solution. Linear Stern-Volmer plots were obtained, and various rate parameters were extracted from the data. The excited state is also quenced in neutral aqueous solution by a range of metal ions and complexes. Rate constants for both oxidative and reductive quenching mechanisms were obtained. In general the rates are faster for this ion than for the corresponding Ru(bipyridine)3(2+) excited state. Similar data were also obtained for the monoprotonated complex in 2M sulfuric acid and the hexaprotonated species in concentrated sulfuric acid. Originator-supplied keywords include: Ruthenium, Bipyrazine, Quenching, Luminescence.