Exploring C(sp3)–C(sp3) reductive elimination from an isolable iron metallacycle

Matthew V. Joannou, Jonathan M. Darmon, Máté J. Bezdek, Paul J. Chirik

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

A six-coordinate iron metallacyclopentane, (phen)2Fe(CH2)4, supported by two 1,10-phenanthroline (phen) ligands, has been synthesized and structurally and spectroscopically characterized. The complex is diamagnetic and an idealized octahedral geometry was observed in the solid state. The electronic structure of (phen)2Fe(CH2)4 was determined by a combination of X-ray diffraction, Mössbauer spectroscopy, and DFT analyses and is best described as a low-spin Fe(III) center antiferromagnetically coupled to a radical anion delocalized equally over both phen ligands. The reactivity of (phen)2Fe(CH2)4 under different conditions was explored. Thermolysis or photolysis promoted elimination reactions and mixtures of isomeric butenes and butane were observed. Reactions of (phen)2Fe(CH2)4 with ethylene and isoprene yielded 3% and 11% of reductive elimination product cyclobutane, respectively, along with butane and butene isomers. Addition of π-accepting ligands such as carbon monoxide, maleic anhydride, or 1,4-benzoquinone to (phen)2Fe(CH2)4 promoted C(sp3)-C(sp3) reductive elimination as judged by high selectivity for cyclobutane formation. Two electron oxidation of (phen)2Fe(CH2)4 with two equivalents of ferrocenium tetraphenylborate also exclusively yielded cyclobutane in 95% yield. The electronic structure and reactivity of related bis(bipyridine) iron dialkyl compounds previously isolated by Kochi and co-workers were also revisited and their electronic structures revised based on structural, spectroscopic and computational data.

Original languageEnglish (US)
Pages (from-to)308-317
Number of pages10
JournalPolyhedron
Volume159
DOIs
StatePublished - Feb 1 2019

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

Keywords

  • Iron
  • Metallocycle
  • Redox active
  • Reductive elimination
  • Spectroscopy

Fingerprint Dive into the research topics of 'Exploring C(sp<sup>3</sup>)–C(sp<sup>3</sup>) reductive elimination from an isolable iron metallacycle'. Together they form a unique fingerprint.

  • Cite this