The reaction of ONOO– with carbonyls: Estimation of the half-lives of ONOOC(O)O– and O2NOOC(O)O–Based on the presentation given at Dalton Discussion No. 4, 10–13th January 2002, Kloster Banz, Germany.

Abstract

The equilibrium constant for the formation of an adduct between a carbonyl and a hydroperoxide ion varies linearly with the acid dissociation constant of the hydroperoxide. Based on this relationship, the half-life of the adduct formed between ONOO- and CO2, ONOOC(O)O-, is estimated to be shorter than 100 ns. Consequently, this adduct should not play any role whatsoever in chemical or biological systems. O2NOO- and CO2 are believed to be involved in a fast equilibrium reaction forming an adduct, O2NOOC(O)O-. This adduct does not appear to homolyse either along the O-O or the N-O bond. Furthermore, at realistic CO2 concentrations, the equilibrium should be shifted far to the O2NOO- + CO2 side. Therefore, the rate of self-decomposition of O2NOO- into NO2- and O-2 is unaffected by the presence of bicarbonate.