{Fe(NO)2}9 Dinitrosyl Iron Complex Acting as a Vehicle for the NO Radical

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• 作者：Chun-Hung Ke ; Chien-Hong Chen ; Ming-Li Tsai ; Hsuan-Chi Wang ; Fu-Te Tsai ; Yun-Wei ChiangWei-Chih Shih ; D. Scott Bohle ; Wen-Feng Liaw
• 刊名：Journal of the American Chemical Society
• 出版年：2017
• 出版时间：January 11, 2017
• 年：2017
• 卷：139
• 期：1
• 页码：67-70
• 全文大小：334K
• ISSN：1520-5126

文摘

To carry and deliver nitric oxide with a controlled redox state and rate is crucial for its pharmaceutical/medicinal applications. In this study, the capability of cationic {Fe(NO)₂}⁹ dinitrosyl iron complexes (DNICs) [(^RDDB)Fe(NO)₂]⁺ (R = Me, Et, Iso; ^RDDB = N,N′-bis(2,6-dialkylphenyl)-1,4-diaza-2,3-dimethyl-1,3-butadiene) carrying nearly unperturbed nitric oxide radical to form [(^RDDB)Fe(NO)₂(^•NO)]⁺ was demonstrated and characterized by IR, UV–vis, EPR, NMR, and single-crystal X-ray diffractions. The unique triplet ground state of [(^RDDB)Fe(NO)₂(^•NO)]⁺ results from the ferromagnetic coupling between two strictly orthogonal orbitals, one from Fe d_z² and the other a π*_op orbital of a unique bent axial NO ligand, which is responsible for the growth of a half-field transition (ΔM_S = 2) from 70 to 4 K in variable-temperature EPR measurements. Consistent with the NO radical character of coordinated axial NO ligand in complex [(^MeDDB)Fe(NO)₂(^•NO)]⁺, the simple addition of MeCN/H₂O into CH₂Cl₂ solution of complexes [(^RDDB)Fe(NO)₂(^•NO)]⁺ at 25 °C released NO as a neutral radical, as demonstrated by the formation of [S₅Fe(NO)₂]⁻ from [S₅Fe(μ-S)₂FeS₅]^2–.