Mechanochemical reactions of fluorides with hemin

Hemin has two potential sites to react with fluorides, the peripheral acid groups and the central Fe^III cation. The mechanochemical reactions of hemin with fluorides (LiF, NaF, KF, CsF, NH₄F and AgF) were monitored using X-ray diffraction (XRD), and IR and Mössbauer spectroscopies. LiF and NaF were found inert when milled with hemin, however KF, CsF, NH₄F and AgF react at both hemin sites. At the iron site Cl^- is replaced by F^- with formation of KCl, CsCl, NH₄Cl, and AgCl, as detected by XRD, while with the peripheral acid groups, fluorides collect the acidic protons to form KHF₂, CsHF₂, NH₄HF and AgHF₂. The reactions of hemin with the reactive fluorides take place first at the iron site and then at the propionic acid groups.