Non-heme (L)FeIII and (L)FeIII-O-FeIII(L) complexes (L=1,1-di(pyridin-2-yl)-N,N-bis(pyridin-2-ylmethyl)ethan-1-amine) underwent reduction under irradiation to the FeII state with concomitant oxidation of methanol to methanal, without the need for a secondary photosensitizer. Spectroscopic and DFT studies support a mechanism in which irradiation results in charge-transfer excitation of a FeIII−μ-O−FeIII complex to generate [(L)FeIV=O]2+ (observed transiently during irradiation in acetonitrile), and an equivalent of (L)FeII. Under aerobic conditions, irradiation accelerates reoxidation from the FeII to the FeIII state with O2, thus closing the cycle of methanol oxidation to methanal.
Bibliographical noteFunding Information:
The COST association action CM1305 ECOSTBio (STSM grant 38503), the European Research Council (ERC 279549, WRB), Labex ARCANE (ANR-11-LABX-003), the Serbian Ministry of Science (OI172035), and the Chinese Scholarship Council (CSC) are acknowledged for financial support. We thank the Center for Information Technology of the University of Groningen for their support and for providing access to the Peregrine high-performance computing cluster. We thank Prof. Edwin Otten for X-ray structural analysis of 3, and Dr. Carole Duboc and Dr. Sandeep Padamati for recording X-band EPR spectra of 3 at 4 K.
© 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.
- diiron complexes
- reaction mechanisms