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This content will become publicly available on June 2, 2026

Title: A Diiron(I/II) μ-1,2-Carbonyl Complex Relevant to CO Binding on Fe(111)
Fischer–Tropsch conversion of syngas to hydrocarbons is proposed to begin with CO binding to the iron surface of the catalyst. CO adsorption on various iron facets of relevance to the Fischer–Tropsch process suggest that the Fe(111) surface is the most active for catalysis, and that CO bound to the penultimate layer of Fe atoms or the b-state is the resting state during catalysis. Notably, a μ-1,2 mode was discarded for the b-state due to a lack of exemplar molecular species and expectation that such a mode would have a higher energy infrared (IR) absorption than observed experimentally (viz. 1735–1860 cm–1). Here, we report the synthesis of a diiron(I/II) complex in which CO binds μ-1,2: (Fe(OTf))(Fe(THF)(μ-1,2-CO))L where L2– is a bis(β-diketiminate) cyclophane (1). Surprisingly, the observed νCO at 1763 cm–1 for 1 compares well with that reported for b-state. Electron paramagnetic resonance (EPR), Mössbauer, and density functional theory (DFT) results support a weakly coupled s = 3/2 iron(I) and s = 2 iron(II) pair. Reduction of 1 results in C–O cleavage and C–C bond formation to yield a ketenylidene (CCO) complex as a major product observed spectroscopically.  more » « less
Award ID(s):
2102098
PAR ID:
10609374
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
American Chemical Society
Date Published:
Journal Name:
Inorganic Chemistry
Volume:
64
Issue:
21
ISSN:
0020-1669
Page Range / eLocation ID:
10488-10495
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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