Mechanochemical reactions of fluorides with hemin

Hemin has two potential sites to react with fluorides, the peripheral acid groups and the central FeIII 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.