Abstract
A series of complexes {[NBu4][LCuII(O2CR)] (R = -C6F5, -C6H4(NO2), -C6H5, -C6H4(OMe), -CH3, and -C6H2(iPr)3)} were characterized (with the complex R = -C6H4(m-Cl) having been published elsewhere (Mandal et al. J. Am. Chem. Soc. 2019, 141, 17236)). All feature N,N′,N″-coordination of the supporting L2- ligand, except for the complex with R = -C6H2(iPr)3, which exhibits N,N′,O-coordination. For the N,N′,N″-bound complexes, redox properties, UV-vis ligand-to-metal charge transfer (LMCT) features, and rates of hydrogen atom abstraction from 2,4,6,-tri-t-butylphenol using the oxidized, formally Cu(III) compounds LCuIII(O2CR) correlated well with the electron donating nature of R as measured both experimentally and computationally. Specifically, the greater the electron donation, the lower is the energy for LMCT and the slower is the reaction rate. The results are interpreted to support an oxidatively asynchronous proton-coupled electron transfer mechanism that is sensitive to the oxidative power of the [CuIII(O2CR)]2+ core.
Original language | English (US) |
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Pages (from-to) | 15872-15879 |
Number of pages | 8 |
Journal | Inorganic chemistry |
Volume | 58 |
Issue number | 23 |
DOIs | |
State | Published - Dec 2 2019 |
Bibliographical note
Funding Information:W.B.T. thanks the NIH for financial support (GM47365), and M.M. and C.J.C. acknowledge funding support as part of the Inorganometallic Catalyst Design Center, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Basic Energy Sciences, under Award No. DESC0012702. We also thank Dr. V. G. Young, Jr. for assistance with X-ray crystallography. X-ray diffraction data were collected using a crystal diffractometer acquired through NSF-MRI Award No. CHE-1229400.
Publisher Copyright:
© 2019 American Chemical Society.