NO Coupling by Nonclassical Dinuclear Dinitrosyliron Complexes to Form N2O Dictated by Hemilability

Walker R Marks; Eric W Reinheimer; Takele Seda; Lev N Zakharov; John D Gilbertson

doi:10.1021/acs.inorgchem.1c02285

NO Coupling by Nonclassical Dinuclear Dinitrosyliron Complexes to Form N₂O Dictated by Hemilability

Inorg Chem. 2021 Nov 1;60(21):15901-15909. doi: 10.1021/acs.inorgchem.1c02285. Epub 2021 Sep 13.

Authors

Walker R Marks¹, Eric W Reinheimer², Takele Seda³, Lev N Zakharov⁴, John D Gilbertson¹

Affiliations

¹ Department of Chemistry, Western Washington University, Bellingham, Washington 98225, United States.
² Rigaku Oxford Diffraction, Woodlands, Texas 77381, United States.
³ Department of Physics, Western Washington University, Bellingham, Washington 98225, United States.
⁴ Department of Chemistry, University of Oregon, Eugene, Oregon 97403, United States.

PMID: 34514780
DOI: 10.1021/acs.inorgchem.1c02285

Abstract

Selective coupling of NO by a nonclassical dinuclear dinitrosyliron complex (D-DNIC) to form N₂O is reported. The coupling is facilitated by the pyridinediimine (PDI) ligand scaffold, which enables the necessary denticity changes to produce mixed-valent, electron-deficient tethered DNICs. One-electron oxidation of the [{Fe(NO)₂}]₂^10/10 complex Fe₂(^PyrrPDI)(NO)₄ (4) results in NO coupling to form N₂O via the mixed-valent {[Fe(NO)₂]₂}^9/10 species, which possesses an electron-deficient four-coordinate {Fe(NO)₂}¹⁰ site, crucial in N-N bond formation. The hemilability of the PDI scaffold dictates the selectivity in N-N bond formation because stabilization of the five-coordinate {Fe(NO)₂}⁹ site in the mixed-valent [{Fe(NO)₂}]₂^9/10 species, [Fe₂(^Pyr2PDI)(NO)₄][PF₆] (6), does not result in an electron-deficient, four-coordinate {Fe(NO)₂}¹⁰ site, and hence no N-N coupling is observed.