A Terminal Imido Complex of an Iron-Sulfur Cluster

Angew Chem Int Ed Engl. 2021 Jun 1;60(23):12802-12806. doi: 10.1002/anie.202102603. Epub 2021 Apr 29.

Abstract

We report the synthesis and characterization of the first terminal imido complex of an Fe-S cluster, (IMes)3 Fe4 S4 =NDipp (2; IMes=1,3-dimesitylimidazol-2-ylidene, Dipp=2,6-diisopropylphenyl), which is generated by oxidative group transfer from DippN3 to the all-ferrous cluster (IMes)3 Fe4 S4 (PPh3 ). This two-electron process is achieved by formal one-electron oxidation of the imido-bound Fe site and one-electron oxidation of two IMes-bound Fe sites. Structural, spectroscopic, and computational studies establish that the Fe-imido site is best described as a high-spin Fe3+ center, which is manifested in its long Fe-N(imido) distance of 1.763(2) Å. Cluster 2 abstracts hydrogen atoms from 1,4-cyclohexadiene to yield the corresponding anilido complex, demonstrating competency for C-H activation.

Keywords: C−H activation; bioinorganic chemistry; cluster compounds; multiple bonds.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Imides / chemistry*
  • Iron / chemistry*
  • Models, Molecular
  • Molecular Structure
  • Sulfur / chemistry*

Substances

  • Imides
  • Sulfur
  • Iron