A new spin on cyclooctatetraene (COT) redox activity: Low-spin iron(I) complexes that exhibit antiferromagnetic coupling to a singly reduced η4-COT ligand

Tufan K. Mukhopadhyay, Marco Flores, Russell K. Feller, Brian L. Scott, R. Dean Taylor, Moshe Paz-Pasternak, Neil J. Henson, Francisca N. Rein, Nathan C. Smythe, Ryan Trovitch, John C. Gordon

Research output: Contribution to journalArticle

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Abstract

Formally zerovalent (κ3-phosphine)Fe(η4-COT) complexes supported by either Triphos (PhP(CH2CH2PPh2)2) or Triphos∗ (H3CC(CH2PPh2)3) have been prepared following chelate addition to (COT)2Fe (COT = 1,3,5,7-cyclooctatetraene) and by reduction of the respective dibromide complexes in the presence of excess COT. The solid-state structure of each complex was determined by single-crystal X-ray diffraction, and close inspection of the metrical parameters revealed significant COT ligand reduction, independent of the coordination geometry about iron. While the neutral and dianionic forms of the redox-active COT ligand have historically received a great deal of attention, a dearth of information regarding the often-evoked radical monoanion form of this ligand prompted the full electronic structure investigation of these complexes using a range of techniques. Comparison of the Mössbauer spectroscopic data collected for both (Triphos)Fe(η4-COT) complexes with data obtained for two appropriate reference compounds indicated that they possess a low-spin Fe(I) center that is antiferromagnetically coupled to a COT radical monoanion. Further evidence for this electronic structure determination by EPR spectroscopy and cyclic voltammetry is presented. A comparison of the solid-state metrical parameters determined in this study to those of related first-row transition-metal complexes has provided insight into the electronic structure analysis of related organometallic complexes.

Original languageEnglish
Pages (from-to)7101-7112
Number of pages12
JournalOrganometallics
Volume33
Issue number24
DOIs
Publication statusPublished - Dec 22 2014

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Electronic structure
phosphine
Iron
electronic structure
Ligands
iron
ligands
solid state
dibromides
Coordination Complexes
Organometallics
chelates
phosphines
Cyclic voltammetry
Transition metals
Paramagnetic resonance
inspection
Inspection
transition metals
Single crystals

ASJC Scopus subject areas

  • Organic Chemistry
  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

Cite this

Mukhopadhyay, T. K., Flores, M., Feller, R. K., Scott, B. L., Taylor, R. D., Paz-Pasternak, M., ... Gordon, J. C. (2014). A new spin on cyclooctatetraene (COT) redox activity: Low-spin iron(I) complexes that exhibit antiferromagnetic coupling to a singly reduced η4-COT ligand. Organometallics, 33(24), 7101-7112. https://doi.org/10.1021/om500909h

A new spin on cyclooctatetraene (COT) redox activity : Low-spin iron(I) complexes that exhibit antiferromagnetic coupling to a singly reduced η4-COT ligand. / Mukhopadhyay, Tufan K.; Flores, Marco; Feller, Russell K.; Scott, Brian L.; Taylor, R. Dean; Paz-Pasternak, Moshe; Henson, Neil J.; Rein, Francisca N.; Smythe, Nathan C.; Trovitch, Ryan; Gordon, John C.

In: Organometallics, Vol. 33, No. 24, 22.12.2014, p. 7101-7112.

Research output: Contribution to journalArticle

Mukhopadhyay, TK, Flores, M, Feller, RK, Scott, BL, Taylor, RD, Paz-Pasternak, M, Henson, NJ, Rein, FN, Smythe, NC, Trovitch, R & Gordon, JC 2014, 'A new spin on cyclooctatetraene (COT) redox activity: Low-spin iron(I) complexes that exhibit antiferromagnetic coupling to a singly reduced η4-COT ligand', Organometallics, vol. 33, no. 24, pp. 7101-7112. https://doi.org/10.1021/om500909h
Mukhopadhyay, Tufan K. ; Flores, Marco ; Feller, Russell K. ; Scott, Brian L. ; Taylor, R. Dean ; Paz-Pasternak, Moshe ; Henson, Neil J. ; Rein, Francisca N. ; Smythe, Nathan C. ; Trovitch, Ryan ; Gordon, John C. / A new spin on cyclooctatetraene (COT) redox activity : Low-spin iron(I) complexes that exhibit antiferromagnetic coupling to a singly reduced η4-COT ligand. In: Organometallics. 2014 ; Vol. 33, No. 24. pp. 7101-7112.
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AU - Mukhopadhyay, Tufan K.

AU - Flores, Marco

AU - Feller, Russell K.

AU - Scott, Brian L.

AU - Taylor, R. Dean

AU - Paz-Pasternak, Moshe

AU - Henson, Neil J.

AU - Rein, Francisca N.

AU - Smythe, Nathan C.

AU - Trovitch, Ryan

AU - Gordon, John C.

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