The Fe2 (NO)2 Diamond Core: A Unique Structural Motif In Non-Heme Iron-NO Chemistry.
The Fe2 (NO)2 Diamond Core: A Unique Structural Motif In Non-Heme Iron-NO Chemistry.
复制标题
Fe2 (NO)2 金刚石核心：非血红素铁-NO 化学中的独特结构基序。
DOI：
10.1002/anie.201911968
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Lehnert,Nicolai
中科院分区：
文献类型：
--
作者：
Dong,HaiT;Speelman,AmyL;Kozemchak,ClaireE;Sil,Debangsu;Krebs,Carsten;Lehnert,Nicolai
非血红素高自旋（hs） {FeNO}8配合物被认为是黄二铁NO还原酶（FNORs）中形成N2O的重要中间体。许多hs - {FeNO}8配合物通过形成二硝基铁配合物（dnic）而不成比例，但这种反应的机制尚不清楚。在研究这一过程时，我们分离出一种新型的非血红素铁亚硝基配合物，该配合物通过意想不到的自旋态变化来稳定。当hs‐{FeNO}7配合物[Fe(TPA)(NO)(OTf)](OTf)(1)还原后，N‐O伸展带消失，但未观察到DNIC或N2O生成的迹象。相反，二聚体[Fe2(TPA)2(NO)2](OTf)2(2)可以被分离出来并进行结构表征。我们认为2是由hs‐{FeNO}8中间体的二聚形成的，随后铁中心的自旋状态转变为低自旋（ls），并推测2在歧化反应之前模拟了hs‐{FeNO}8配合物中的中间体。
Non‐heme high‐spin (hs) {FeNO}8complexes have been proposed as important intermediates towards N2O formation in flavodiiron NO reductases (FNORs). Many hs‐{FeNO}8complexes disproportionate by forming dinitrosyl iron complexes (DNICs), but the mechanism of this reaction is not understood. While investigating this process, we isolated a new type of non‐heme iron nitrosyl complex that is stabilized by an unexpected spin‐state change. Upon reduction of the hs‐{FeNO}7complex, [Fe(TPA)(NO)(OTf)](OTf) (1), the N‐O stretching band vanishes, but no sign of DNIC or N2O formation is observed. Instead, the dimer, [Fe2(TPA)2(NO)2](OTf)2(2) could be isolated and structurally characterized. We propose that2is formed from dimerization of the hs‐{FeNO}8intermediate, followed by a spin state change of the iron centers to low‐spin (ls), and speculate that2models intermediates in hs‐{FeNO}8complexes that precede the disproportionation reaction.