Conversion of high-spin iron(iii)-alkylperoxo to iron(iv)-oxo species via O-O bond homolysis in nonheme iron models

Seungwoo Hong, Yong Min Lee, Kyung Bin Cho, Mi Sook Seo, Dayoung Song, Jihae Yoon, Ricardo Garcia-Serres, Martin Clémancey, Takashi Ogura, Woonsup Shin, Jean Marc Latour, Wonwoo Nam

Research output: Contribution to journalArticlepeer-review

37 Scopus citations

Abstract

The mechanism of the alkylperoxo O-O bond cleavage of low-spin iron(iii)-alkylperoxo species has been well established in nonheme iron models. In contrast, the alkylperoxo O-O bond cleavage in nonheme high-spin iron(iii)-alkylperoxo species binding an axial ligand has yet to be elucidated. Herein, we report the synthesis and characterization of mononuclear nonheme high-spin iron(iii)-alkylperoxo complexes each bearing an N-tetramethylated 13-membered macrocyclic ligand (13-TMC), [FeIII(OOC(CH 3)3)(13-TMC)]2+ and [Fe III(OOC(CH3)2C6H5)(13- TMC)]2+. The high-spin iron(iii)-alkylperoxo complexes were converted to an iron(iv)-oxo complex at a fast rate upon addition of thiocyanate (NCS-) via the formation of a short-lived intermediate. This intermediate was identified as a high-spin iron(iii)-alkylperoxo complex binding a thiocyanate ion as an axial ligand by characterizing it with various spectroscopic methods and density functional theory (DFT) calculations. We have also provided strong evidence that conversion of the high-spin iron(iii)-alkylperoxo complex to its corresponding iron(iv)-oxo complex occurs via O-O bond homolysis. Thus, we have concluded that the role of the axial ligand binding to a high-spin iron(iii)-alkylperoxo complex is to facilitate the alkylperoxo O-O bond cleavage via the "push effect", which has been well established in heme enzymes. To the best of our knowledge, the present study reports the first clear example showing the O-O bond homolysis of a high-spin iron(iii)-alkylperoxo complex and the axial ligand effect on the alkylperoxo O-O bond cleavage in nonheme iron models.

Original languageEnglish
Pages (from-to)156-162
Number of pages7
JournalChemical Science
Volume5
Issue number1
DOIs
StatePublished - Jan 2014

Fingerprint

Dive into the research topics of 'Conversion of high-spin iron(iii)-alkylperoxo to iron(iv)-oxo species via O-O bond homolysis in nonheme iron models'. Together they form a unique fingerprint.

Cite this