Intramolecular oxidation of the ligand 4-methyl-2-N-(2-pyridylmethyl)aminophenol (Hpyramol) upon coordination with iron(II) chloride and manganese(II) perchlorate

The ligand Hpyramol (Hpyramol=4-methyl-2-N-(2-pyridylmethyl)aminophenol) is found to undergo an oxidative dehydrogenation of its amine function to an imine group upon coordination with iron(II) chloride and manganese(II) perchlorate. X-ray diffraction analyses for both complexes shows differences in the coordination geometry of the complexes most likely because of the two different counter-ions namely the strong coordinating chloride anions and the weak coordinating perchlorate anions. The coordination sphere of the iron(III) complex in [FeCl2(pyrimol)(MeOH)](MeOH) is best described as a distorted octahedral FeN2O2Cl2 chromophore, while the manganese(II) ions in [Mn(ClO4)(pyrimol)(Hpyrimol)]2 are in a distorted octahedral MnN4O2 environment with a 2:1 ligand to metal ratio instead of 1:1.