A High-Valent Manganese(IV)-Oxo-Cerium(IV) Complex and Its Enhanced Oxidizing Reactivity.

A mononuclear nonheme manganese(IV)-oxo complex binding the Ce4+ ion, [(dpaq)MnIV (O)]+ -Ce4+ (1-Ce4+ ), was synthesized by reacting [(dpaq)MnIII (OH)]+ (2) with cerium ammonium nitrate (CAN). 1-Ce4+ was characterized using various spectroscopic techniques, such as UV/Vis, EPR, CSI-MS, resonance Raman, XANES, and EXAFS, showing an Mn-O bond distance of 1.69 Å with a resonance Raman band at 675 cm-1 . Electron-transfer and oxygen atom transfer reactivities of 1-Ce4+ were found to be greater than those of MnIV (O) intermediates binding redox-inactive metal ions (1-Mn+ ). This study reports the first example of a redox-active Ce4+ ion-bound MnIV -oxo complex and its spectroscopic characterization and chemical properties.