Abstract
This article uses theory to address the origins of the reactivity differences between MnIV=O and MnIV-OH complexes, having identical ligand spheres and metal oxidation states, toward 9,10-dihydroanthracene (DHA) under different pH conditions. Theory discovers different non-rebound mechanisms leading to unique products for the two complexes. One of these is a novel mechanism that operates under basic conditions and that rationalizes the formation of anthraquinone through an anthracene radical anion intermediate. In addition, the calculations reveal a rich mechanistic scheme having blended hydrogen atom transfer and proton-coupled electron transfer (HAT/PCET) with both proton transfer/electron transfer (PT/ET) and electron transfer/proton transfer (ET/PT) characters. The distinct nature of the transition states, such as PT/ET and ET/PT, for the second H-abstraction reactions from the substrate radical by the MnIV=O and MnIV-OH complexes accounts for the observed product distributions for these two species. The formation of an anthracene radical anion, and its participation in a unique non-rebound mechanism, is a testable prediction.
Original language | English |
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Pages (from-to) | 2877-2888 |
Number of pages | 12 |
Journal | ACS Catalysis |
Volume | 6 |
Issue number | 5 |
DOIs | |
State | Published - 6 May 2016 |
Bibliographical note
Publisher Copyright:© 2016 American Chemical Society.
Keywords
- anthracene radical anion
- ET/PT
- Mn-hydroxo
- Mn-oxo
- non-rebound
- PT/ET