Oxygen Atom Transfer Reaction of Manganese-oxo Corrole toward Dimethyl Sulfide: a Density Functional Study

The effects of axial ligand on the oxygen atom transfer(OAT) reaction from 5,10,15-tris(pentafluorophenyl) corrole((tpfc)MnVO) to dimethyl sulfide(DMS) have been investigated by density functional theory(DFT) calculations. Imidazole(Im), 4-methylimidazole(4-MI) and pyridine(Py) were selected as the axial ligands. The results revealed that the axial ligand can form coordinate bond with(tpfc)MnVO in the transition state(TS) of the OAT reaction. The axial coordination favored charge transferring from(tpfc)MnVO to DMS, and weakened the Mn≡O bond in both singlet and triplet states. Furthermore, axial coordination can reduce the energy barrier of neutral(tpfc)MnVO from 23.62 kJ·mol-1 to less than 3 kJ·mol-1 in the triplet state, which is significantly lower than in the singlet state. This makes(tpfc)MnVO tend to direct the OAT reaction via triplet state pathway. On the other hand, the energy barriers of [(tpfc)MnVIO]+ species from disproportionation pathway increased from 1.26 to 33.95 kJ·mol-1 in a doublet state. This suggests axial ligands were conducive for direct(tpfc)MnVO OAT reaction pathway.