From activation of dioxygen to formation of high-valent oxo species: Ab initio DFT studies

The aim of present Density Functional Theory (DFT) study is the modeling of an activation of molecular oxygen on the manganese porphyrin and a simulation of a set of subsequent processes of hydrogen adsorption, which can lead to the formation of the reactive high-valent manganese-oxo species. Results of the performed calculations reveal that the molecular oxygen may be bound to the reduced manganese porphyrin forming either superoxo or peroxo group. In each case the O2 molecule is activated. The adsorption of the hydrogen atom on the O2 molecule leads to the weakening of the O–O bond. The latter is cleaved once the second hydrogen atom becomes adsorbed. As a result the water molecule is formed. The remaining oxygen atom is doubly bound to manganese ion resulting in the high-valent oxo complex.

Graphical abstractThe paper presents Density Functional Theory studies on the activation of molecular oxygen on the manganese porphyrin and a simulation of a set of subsequent processes of hydrogen adsorption. These can lead to the formation of the reactive high-valent manganese-oxo species.Figure optionsDownload full-size imageDownload as PowerPoint slide