(ImRN)2Fe: An Elusive Complex and the Limits of Its Ferrocene Analogy
- 1Department of Chemistry and Biochemistry
- 2University of Texas at El Paso
- 3New Mexico State University
Abstract
The isolobal relationship between imidazolin-2-iminato and cyclopentadienyl ligands makes the iron bis(imidazolin-2-iminato) complex (Im R N) 2 Fe an attractive target as a potential ferrocene analog, yet reported efforts toward its isolation have been unsuccessful. Herein, we report the synthesis of (Im Dipp N) 2 Fe ( 1 ) by protonolysis of Fe 2 Mes 4 with Im Dipp NH, affording a linear, two-coordinate, high-spin Fe(II) complex (S = 2). Its coordinative unsaturation permits binding of THF, an aryl isocyanide, and TEMPO, affording complexes with varied geometries. Unlike ferrocene, the electrochemical properties of 1 depend strongly on its ancillary ligands. Oxidation with AgPF 6 affords a Ag-bound Fe(II) intermediate 1-Ag that undergoes photochemical conversion to the Fe(III) complex [(Im Dipp N) 2 Fe(Solv) 2 ][PF 6 ] ( 2 ). These results establish 1 as a distinct low-coordinate iron complex whose coordination and redox chemistry extend beyond its proposed ferrocene analogy.
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BibTeX
@misc{saucedo2026imrn2fe,
title = {{(ImRN)2Fe: An Elusive Complex and the Limits of Its Ferrocene Analogy}},
author = {Manuel Saucedo and Alejandra Gomez-Torres and Iván E. Arvizo and Bayler G. Barnes and Cory J. Windorff and Alejandro Metta-Magaña and Skye Fortier},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15010611/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010611/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - (ImRN)2Fe: An Elusive Complex and the Limits of Its Ferrocene Analogy
AU - Manuel Saucedo
AU - Alejandra Gomez-Torres
AU - Iván E. Arvizo
AU - Bayler G. Barnes
AU - Cory J. Windorff
AU - Alejandro Metta-Magaña
AU - Skye Fortier
PY - 2026
DA - 2026/10/16
PB - ChemRxiv
DO - 10.26434/chemrxiv.15010611/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010611/v1
AB - The isolobal relationship between imidazolin-2-iminato and cyclopentadienyl ligands makes the iron bis(imidazolin-2-iminato) complex (Im R N) 2 Fe an attractive target as a potential ferrocene analog, yet reported efforts toward its isolation have been unsuccessful. Herein, we report the synthesis of (Im Dipp N) 2 Fe ( 1 ) by protonolysis of Fe 2 Mes 4 with Im Dipp NH, affording a linear, two-coordinate, high-spin Fe(II) complex (S = 2). Its coordinative unsaturation permits binding of THF, an aryl isocyanide, and TEMPO, affording complexes with varied geometries. Unlike ferrocene, the electrochemical properties of 1 depend strongly on its ancillary ligands. Oxidation with AgPF 6 affords a Ag-bound Fe(II) intermediate 1-Ag that undergoes photochemical conversion to the Fe(III) complex [(Im Dipp N) 2 Fe(Solv) 2 ][PF 6 ] ( 2 ). These results establish 1 as a distinct low-coordinate iron complex whose coordination and redox chemistry extend beyond its proposed ferrocene analogy.
ER -