Antioxidative Reactivity of L-Ascorbic Acid and D-Isoascorbic Acid Species towards Reduction of Hexachloroiridate (IV)

Figure 7

(a) Species of AA versus pH distribution diagram (cf. Scheme 2). (b) Reactivity of AA species versus pH diagram computed by use of k₁ = 451 M⁻¹s⁻¹, k₂ = 2.28 × 10⁷ M⁻¹s⁻¹ and k₃ = 1 × 10¹⁰ M⁻¹s⁻¹ (a diffusion-controlled rate constant in aqueous solution). (I) Fully protonated form of AA; (II) monoanionic form of AA; (III) dianionic form of AA.