Jiang Yunbo, Hayashi Takahiro, Matsumura Hirotoshi, Do Loi H, Majumdar Amit, Lippard Stephen J, Moënne-Loccoz Pierre
Institute of Environmental Health, Oregon Health and Science University , Portland, Oregon 97239, United States.
J Am Chem Soc. 2014 Sep 10;136(36):12524-7. doi: 10.1021/ja504343t. Epub 2014 Aug 27.
Two non-heme iron-nitrosyl species, Fe2(N-Et-HPTB)(O2CPh)(NO)22 (1a) and Fe2(N-Et-HPTB)(DMF)2(NO)(OH)3 (2a), are characterized by FTIR and resonance Raman spectroscopy. Binding of NO is reversible in both complexes, which are prone to NO photolysis under visible light illumination. Photoproduction of N2O occurs in high yield for 1a but not 2a. Low-temperature FTIR photolysis experiments with 1a in acetonitrile do not reveal any intermediate species, but in THF at room temperature, a new {FeNO}(7) species quickly forms under illumination and exhibits a ν(NO) vibration indicative of nitroxyl-like character. This metastable species reacts further under illumination to produce N2O. A reaction mechanism is proposed, and implications for NO reduction in flavodiiron proteins are discussed.
两种非血红素铁-亚硝酰基物种，Fe2(N-Et-HPTB)(O2CPh)(NO)22 (1a) 和 Fe2(N-Et-HPTB)(DMF)2(NO)(OH)3 (2a)，通过傅里叶变换红外光谱 (FTIR) 和共振拉曼光谱进行了表征。在这两种配合物中，NO 的结合都是可逆的，并且在可见光照射下它们都易于发生 NO 光解。对于 1a，N2O 的光产生产率很高，但对于 2a 则不然。在乙腈中对 1a 进行低温 FTIR 光解实验未发现任何中间物种，但在室温下的四氢呋喃中，一种新的 {FeNO}(7) 物种在光照下迅速形成，并表现出指示类硝酰基特征的 ν(NO) 振动。这种亚稳物种在光照下进一步反应生成 N2O。提出了一种反应机理，并讨论了其对黄素二铁蛋白中 NO 还原的影响。
