The reaction of ferrimyoglobin with methylhydroperoxide

Abstract

Methylhydroperoxide reacts with ferrimyoglobin in an irreversible reaction. In the course of the reaction two intermediates are formed in two consecutive steps. The experimental data are consistent with a mechanism in which MeOOH is dehydrated catalytically by ferrimyoglobin to yield CH₂O. MeOH is not formed in the system, even as a transient. The relative rate constants of the reaction have been evaluated: k₁= 1 dm³ mol^–1 s^–1. k₂= 2.23 × 10^–4 s^–1 and k₃= 4.0 × 10^–6 s^–1. The molar absorptivities of the intermediates have been determined at λ= 549 nm: ε_I= 1.75 × 10⁴ dm³ mol^–1 cm^–1 and ε_II= 6.32 × 10³ dm³ mol^–1 cm^–1.