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

Abstract

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. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim