Effects of Substituents and Anionic Ligands on Axial Coordination of (TPFC)Mn(V)O

The axial coordination of a series of site substituted manganese(V) oxygen corrole complexes ((TPFC)MnVO) with imidazole and the non-substituted (TPFC)MnVO with 4-methyl imidazole and pyrrole were investigated using the density functional theory (DFT) with BP86 method. The calculation results show that the electron-withdrawing ability of the -substituents and the anionic effect of the axial ligand can both result in a short length of coordination bond and the strong binding energy, which significantly enhance the axial coordination interaction of the (TPFC)MnVO complex. The main factors affecting the axial coordination is the second order perturbation stabilization energies E(2) which including lone pair electron orbit of nitrogen on the axial ligand (LP(N)) to the lone pair electron orbital of manganese (LP(Mn,4S)) and to the anti bond orbital of manganese oxygen bond (*(MnO)) by the natural bond orbital (NBO) analysis, respectively. The axial coordination of (TPFC)MnVO is enhanced significantly by the strong electron-withdrawing ability of the substituents and the anionic axial ligands.