Formation of [Ru(III)(edta)(SNO)](2-) in Ru(III)(edta)-Mediated S-Nitrosylation of Bisulfide Ion.

The reaction of hydrogen sulfide (H2S) and nitric oxide (NO) is of great physiological significance in human organisms. Our present studies show that Ru(III)(edta) (edta(4-) = ethylenediaminetetraacetate) mediates the S-nitrosylation of bisulfide ion (HS(-)) using NO to form [Ru(III)(edta)(SNO)](2-), the first-ever example of a ruthenium complex containing thionitrite (SNO(-)) in aqueous solution. The reaction product [Ru(III)(edta)(SNO)](2-) was characterized by IR, electron paramagnetic resonance, and electrospray ionization mass spectroscopy.

Ru(EDTA) mediated partial reduction of O2 by H2S.

An effective procedure for selective reduction of O2 to H2O2 exploring the use of hydrogen sulfide, an obnoxious industrial pollutant as reductant is reported herein. The reduction of [Ru(III)(EDTA)pz](-) (EDTA(4-) = ethylenediaminetetraacetate; pz = pyrazine) by hydrogen sulfide resulting in the formation of a red [Ru(II)(EDTA)pz](2-) complex (λmax = 462 nm) has been studied spectrophotometrically and kinetically using both rapid scan and stopped-flow techniques. The time course of the reaction was followed as a function of [HS(-)]i, pH (5.