TY - JOUR
T1 - A Manganese(IV)-Hydroperoxo Intermediate Generated by Protonation of the Corresponding Manganese(III)-Superoxo Complex
AU - Lin, Yen Hao
AU - Kutin, Yury
AU - Van Gastel, Maurice
AU - Bill, Eckhard
AU - Schnegg, Alexander
AU - Ye, Shengfa
AU - Lee, Way Zen
N1 - Funding Information:
We thank Mr. Dennis Skerra at the Max-Planck Institute for Chemical Energy Conversion for rR measurements and Dr. Tzu-Hsien Tseng at Department of Chemistry, National Chung Hsing University, for variable-temperature CW X-band EPR measurements. The authors are grateful for the financial support from the Ministry of Science and Technology of Taiwan (MOST 108-2113-M-003-009-MY3 to W.-Z.L.) and the Max-Planck Society, in particular, the joint work space of MPI-CEC and MPI-KOFO. W.-Z.L. and S.Y. also acknowledge the MOST-DAAD Project-Based Personnel Exchange Program (MOST 107-2911-I-003-502 and DAAD 57320810).
Publisher Copyright:
Copyright © 2020 American Chemical Society.
PY - 2020/6/10
Y1 - 2020/6/10
N2 - Earlier work revealed that metal-superoxo species primarily function as radicals and/or electrophiles. Herein, we present ambiphilicity of a MnIII-superoxo complex revealed by its proton- A nd metal-coupled electron-transfer processes. Specifically, a MnIV-hydroperoxo intermediate, [Mn(BDPBrP)(OOH)]+ (1, H2BDPBrP = 2,6-bis((2-(S)-di(4-bromo)phenylhydroxylmethyl-1-pyrrolidinyl)methyl)pyridine) was generated by treatment of a MnIII-superoxo complex, Mn(BDPBrP)(O2â¢) (2) with trifluoroacetic acid at-120 °C. Detailed insights into the electronic structure of 1 are obtained using resonance Raman and multi-frequency electron paramagnetic resonance spectroscopies coupled with density functional theory calculations. Similarly, the reaction of 2 with scandium(III) triflate was shown to give a Mn(IV)/Sc(III) bridging peroxo species, [Mn(BDPBrP)(OO)Sc(OTf)n](3-n)+ (4). Furthermore, it is found that deprotonation of 1 quantitatively regenerates 2, and that one-electron oxidation of the corresponding MnIII-hydroperoxo species, Mn(BDPBrP)(OOH) (3), also yields 1.
AB - Earlier work revealed that metal-superoxo species primarily function as radicals and/or electrophiles. Herein, we present ambiphilicity of a MnIII-superoxo complex revealed by its proton- A nd metal-coupled electron-transfer processes. Specifically, a MnIV-hydroperoxo intermediate, [Mn(BDPBrP)(OOH)]+ (1, H2BDPBrP = 2,6-bis((2-(S)-di(4-bromo)phenylhydroxylmethyl-1-pyrrolidinyl)methyl)pyridine) was generated by treatment of a MnIII-superoxo complex, Mn(BDPBrP)(O2â¢) (2) with trifluoroacetic acid at-120 °C. Detailed insights into the electronic structure of 1 are obtained using resonance Raman and multi-frequency electron paramagnetic resonance spectroscopies coupled with density functional theory calculations. Similarly, the reaction of 2 with scandium(III) triflate was shown to give a Mn(IV)/Sc(III) bridging peroxo species, [Mn(BDPBrP)(OO)Sc(OTf)n](3-n)+ (4). Furthermore, it is found that deprotonation of 1 quantitatively regenerates 2, and that one-electron oxidation of the corresponding MnIII-hydroperoxo species, Mn(BDPBrP)(OOH) (3), also yields 1.
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U2 - 10.1021/jacs.0c02756
DO - 10.1021/jacs.0c02756
M3 - Article
C2 - 32412757
AN - SCOPUS:85086356505
VL - 142
SP - 10255
EP - 10260
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 23
ER -