EPR study of the state of manganese stearate in solution in aromatic solvents

Manganese stearate MnSt2 is widely used as a catalyst of the liquid-phase oxidation of paraffinic and alkylaromatic hydrocarbons. Results are given in this work of the study by EPR spectroscopy of the structural and valence transformations of MnSt2, used previously as catalyst for the oxidation of 2-chloro-p-xylene and for decomposition of the corresponding hydroperoxides. The integral intensity I of the differential EPR spectra was determined by the graphical integration method. However, for comparison, the authors frequently used I/I0 is the integral intensity of MnSt2 in the solid phase. Broadening of the EPR line of Mn(II) in solutions of up to 320 G and decrease in the relative integral intensity of I/I0 was due to the formation of MnSt2-ROOH complexes. The decrease in the I/I0 ratio of the EPR signal, observed during the analysis of samples in the course of the dissociation reaction of 2-chloro-p-xylene hydroperoxides, is caused by the Mn(II) → Mn(III) transformation