title: Ruthenium(II) tris(bipyridyl) ion as a luminescent probe for oxygen uptake on the catalyzed oxidation of HSO(3)(-).
abstract: The present work describes an alternative technique for monitoring the rate of oxygen consumption during the oxidation of HSO(3)(-) catalyzed by manganese and iron ions. The method is based on the spectrofluorimetric monitoring of the quenching effect of molecular oxygen on the emission of the photoexcited [Ru(bipy)(3)](2+) ion, added to the reaction mixtures. The effects of Fe(III), at very low concentrations, and of Mn(II) on the oxidation of HSO(3)(-) by dissolved oxygen, have been investigated. The metal ions in the trivalent oxidation state react with HSO(3)(-) to initiate a radical chain reaction in which HSO(3)(-) is oxidized to sulfate and the metal ion is reduced to the divalent state. The synergistic effect of Mn(II) and Fe(III) was clearly evaluated. Possible parallel reactions with the oxygen indicator, [Ru(bipy)(3)](2+), are considered.
authors.affiliation: Instituto de Quimica, Universidade de São Paulo, Caixa Postal 26077, CEP 05513-970, Sao Paulo, SP, Brazil.
authors.forename: Solange
authors.initials: S
authors.lastname: Lima
authors.forename: Rodrigo Leandro
authors.initials: RL
authors.lastname: Bonifácio
authors.forename: Gianluca Camillo
authors.initials: GC
authors.lastname: Azzellini
authors.forename: Nina
authors.initials: N
authors.lastname: Coichev