The effect of salts on the rate constants for quenching of luminescence of tris(2,2'- bipyridyl)ruthenium(II) complexes and on dissociation constants of radical-ion pairs

A.B. Artyukhin, V.L. Ivanov

Chem.Phys.Reports, v.17 (12), p. 2249-2262, (1999)

ABSTRACTS. The rate constants for luminescence quenching of tris(2,2'- bipyridyl)ruthenium(II) complexes by sulphite ions and the ionic form of 1-bromo-2-naphthol and yields of free radical ions from radical-ion pairs are measured as functions of the salt concentration in an aqueous solution. It is reliably established that upon addition of inorganic salts (sodium perchlorate, sulphate and sulphite, potassium bromine) to system, the yield of radical ions reduces with increasing salt concentration in both cases. However, the absolute yield of radical ions from radical-ion pairs of univalent ruthenium complex with sulphite radical-anion and naphthoxy radical and their dependencies on salt concentration differ dramatically. The commonly accepted model allowing for variation in the diffusion rate of the reagents and formation of ion pairs upon addition of salts fails to account for the results obtained. Alternative models are also considered.

Laboratory of Photochemistry