NO-to-[N2O2]2--to-N2O Conversion Triggered by {Fe(NO)2}10-{Fe(NO)2}9 Dinuclear Dinitrosyl Iron Complex

Wun-Yan Wu; Chia-Ning Hsu; Chieh-Hsin Hsieh; Tzung-Wen Chiou; Ming-Li Tsai; Ming-Hsi Chiang; Wen-Feng Liaw

doi:10.1021/acs.inorgchem.9b01635

NO-to-[N₂O₂]^2--to-N₂O Conversion Triggered by {Fe(NO)₂}¹⁰-{Fe(NO)₂}⁹ Dinuclear Dinitrosyl Iron Complex

Inorg Chem. 2019 Aug 5;58(15):9586-9591. doi: 10.1021/acs.inorgchem.9b01635. Epub 2019 Jul 11.

Authors

Wun-Yan Wu¹, Chia-Ning Hsu¹, Chieh-Hsin Hsieh¹, Tzung-Wen Chiou¹, Ming-Li Tsai², Ming-Hsi Chiang³, Wen-Feng Liaw¹

Affiliations

¹ Department of Chemistry and Frontier Research Center of Fundamental and Applied Science of Matters , National Tsing Hua University , Hsinchu 30013 , Taiwan.
² Department of Chemistry , National Sun Yat-sen University , Kaohsiung 80424 , Taiwan.
³ Institute of Chemistry , Academia Sinica , Nankang, Taipei 115 , Taiwan.

PMID: 31294544
DOI: 10.1021/acs.inorgchem.9b01635

Abstract

Flavodiiron nitric oxide reductases (FNORs) evolved in some pathogens are known to detoxify NO via two-electron reduction to N₂O to mitigate nitrosative stress. In this study, we describe how the electronically localized {Fe(NO)₂}¹⁰-{Fe(NO)₂}⁹ dinuclear dinitrosyl iron complex (dinuclear DNIC) [(NO)₂Fe(μ-bdmap)Fe(NO)₂(THF)] (2) (bdmap = 1,3-bis(dimethylamino)-2-propanolate) can induce a reductive coupling of NO to form hyponitrite-coordinated tetranuclear DNIC, which then converts to N₂O. Upon the addition of 1 equiv of NO into the dinuclear {Fe(NO)₂}¹⁰-{Fe(NO)₂}⁹ DNIC 2, the proposed side-on-bound [NO]^--bridged [(NO)₂Fe(μ-bdmap)(κ²-NO) Fe(NO)₂] intermediate may facilitate intermolecular (O)N-N(O) bond coupling to yield the paramagnetic tetranuclear quadridentate trans-hyponitrite-bound {[(NO)₂Fe(μ-bdmap)Fe(NO)₂]₂(κ⁴-N₂O₂)} that transforms to [Fe(NO)₂(μ-bdmap)]₂, along with the release of N₂O upon Hbdmap (1,3-bis(dimethylamino)-2-propanol) added.