The reaction of Fe(III) myoglobin fluoride with reducing agents.

The reaction of reducing agents with Fe(III) myoglobin fluoride from sperm whale was studied at alkaline pH values. The rate of reduction by dithionite was indistinguishable from the rate of ligand dissociation even when the values of the rate constants for both were only 1.0 X 10(-3)S-1 (at pH 10.6). Reduction by the reduced Methyl Viologen radical ion and reduced Safranine was faster than the rate of dissociation, providing evidence that these reductants can donate electrons to the iron centre via a pathway involving an (undetectable) liganded Fe(II) intermediate.