Infrared Spectroelectrochemistry of Iron-Nitrosyl Triarylcorroles. Implications for Ligand Noninnocence

Authors

Md. Hafizur Rahman, Marquette UniversityFollow
Michael D. Ryan, Marquette UniversityFollow
Hugo Vazquez-Lima, Arctic University of Tromsø
Abraham Alemayehu, Arctic University of Tromsø
Abhik Ghosh, Arctic University of Tromsø

Document Type

Article

Language

eng

Publication Date

3-2020

Publisher

American Chemical Society

Source Publication

Inorganic Chemistry

Source ISSN

0020-1669

Abstract

Recent DFT calculations have suggested that iron nitrosyl triarylcorrole complexes have substantial {FeNO}⁷–corrole^•2– character. With this formulation, reduction of Fe(C)(NO) complexes, where C = triarylcorrole, should be centered on the corrole macrocycle rather than on the {FeNO}⁷ moiety. To verify this proposition, visible and infrared spectroelectrochemical studies of Fe(C)(NO) were carried out and the results were interpreted using DFT (B3LYP/STO-TZP) calculations. The first reduction of Fe(C)(NO) led to significant changes in the Soret and Q-band regions of the visible spectrum as well as to a significant downshift in the ν_NO and changes in the corrole vibrational frequencies. DFT calculations, which showed that the electron was mostly added to the corrole ligand (85%), were also able to predict the observed shifts in the ν_NO and corrole bands upon reduction. These results underscore the importance of monitoring both the corrole and nitrosyl vibrations in ascertaining the site of reduction. By contrast, the visible spectroelectrochemistry of the second reduction revealed only minor changes in the Soret band upon reduction, consistent with the reduction of the FeNO moiety.

Comments

Accepted version. Inorganic Chemistry, Vol. 59, No. 5 (March 2020): 3232-3238. DOI. © 2020 American Chemical Society. Used with permission.

Recommended Citation

Rahman, Md. Hafizur; Ryan, Michael D.; Vazquez-Lima, Hugo; Alemayehu, Abraham; and Ghosh, Abhik, "Infrared Spectroelectrochemistry of Iron-Nitrosyl Triarylcorroles. Implications for Ligand Noninnocence" (2020). Chemistry Faculty Research and Publications. 1020.
https://epublications.marquette.edu/chem_fac/1020