Solvent driven spontaneous reduction of Fe(III) porphyrins under CO: a mechanistic and spectroscopic study
Abstract
Iron porphyrins are prototypical complexes for redox transformations involving small molecules such as O 2 , CO and CO₂. For example, the [(pTMA)Fe III (Cl)] 4+ catalyzed CO₂ electroreduction to CO with high rate and selectivity from the Fe⁰ formal oxidation state. We report here and rationalize the spontaneous, unexpected interaction between [(pTMA)Fe III (Cl)] 4+ and CO, which reveals a reduction process of Fe III to an Fe II (CO) adduct occurring at open circuit potential. This process is exquisitely dependent on the porphyrin concentration, coordination environment and the nature of the solvent. Notably, tetrahydrofuran (THF) uniquely suppresses the reaction process, suggesting that the solvent itself may act as the electron donor. Although the reductant could not be directly identified, electrochemical and spectroelectrochemical results collectively point to a spontaneous redox interplay between CO coordination and solvent reactivity.
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BibTeX
@article{salame2026solvent,
title = {{Solvent driven spontaneous reduction of Fe(III) porphyrins under CO: a mechanistic and spectroscopic study}},
author = {Aude Salamé and Mun Hon Cheah and Julien Bonin and Marc Robert and Elodie Anxolabéhère-Mallart},
journal = {Electrochimica Acta},
year = {2026},
month = sep,
doi = {10.1016/j.electacta.2026.150044},
url = {https://hal.science/hal-05770939v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Solvent driven spontaneous reduction of Fe(III) porphyrins under CO: a mechanistic and spectroscopic study
AU - Aude Salamé
AU - Mun Hon Cheah
AU - Julien Bonin
AU - Marc Robert
AU - Elodie Anxolabéhère-Mallart
PY - 2026
DA - 2026/09/21
JO - Electrochimica Acta
DO - 10.1016/j.electacta.2026.150044
UR - https://hal.science/hal-05770939v1
AB - Iron porphyrins are prototypical complexes for redox transformations involving small molecules such as O 2 , CO and CO₂. For example, the [(pTMA)Fe III (Cl)] 4+ catalyzed CO₂ electroreduction to CO with high rate and selectivity from the Fe⁰ formal oxidation state. We report here and rationalize the spontaneous, unexpected interaction between [(pTMA)Fe III (Cl)] 4+ and CO, which reveals a reduction process of Fe III to an Fe II (CO) adduct occurring at open circuit potential. This process is exquisitely dependent on the porphyrin concentration, coordination environment and the nature of the solvent. Notably, tetrahydrofuran (THF) uniquely suppresses the reaction process, suggesting that the solvent itself may act as the electron donor. Although the reductant could not be directly identified, electrochemical and spectroelectrochemical results collectively point to a spontaneous redox interplay between CO coordination and solvent reactivity.
SN - 0013-4686
ER -