The Reaction of Ozone with Bisulfide (HS-) in Aqueous Solution - Mechanistic Aspects

摘要

abstract_textpThe ozone demand to oxidize HS-/H2S [pKa(H2S) = 6.9, k(HS- + O3) = 3 x 109 M-1 s-1, k(H2S + O3) = 3 x 104 M-1 s-1] to SO42- is only 2.4 mol ozone per mol SO42- formed, much lower than stoichiometric 4.0 mol/mol if a series of O-transfer reactions would occur. As primary step, the formation of an ozone adduct to HS-, HSOOO-, is suggested that decomposes into HSO- and singlet oxygen (16%) or rearranges into peroxysulfinate ion, HS(O)OO- (84%). Potential reactions of the above intermediates are discussed. Some of these can account for the low ozone demand./p/abstract_text