A High‐Valent Non‐Heme μ‐Oxo Manganese(IV) Dimer Generated from a Thiolate‐Bound Manganese(II) Complex and Dioxygen

Abstract

Abstract This study deals with the unprecedented reactivity of dinuclear non‐heme Mn II –thiolate complexes with O 2 , which dependent on the protonation state of the initial Mn II dimer selectively generates either a di‐μ‐oxo or μ‐oxo‐μ‐hydroxo Mn IV complex. Both dimers have been characterized by different techniques including single‐crystal X‐ray diffraction and mass spectrometry. Oxygenation reactions carried out with labeled 18 O 2 unambiguously show that the oxygen atoms present in the Mn IV dimers originate from O 2 . Based on experimental observations and DFT calculations, evidence is provided that these Mn IV species comproportionate with a Mn II precursor to yield μ‐oxo and/or μ‐hydroxo Mn III dimers. Our work highlights the delicate balance of reaction conditions to control the synthesis of non‐heme high‐valent μ‐oxo and μ‐hydroxo Mn species from Mn II precursors and O 2 .