Synthesis of New[8Fe-7S] Clusters : A Topological Link Between the Core Structures of P-cluster, FeMo-co, and FeFe-co of Nitrogenases
Synthesis of New[8Fe-7S] Clusters : A Topological Link Between the Core Structures of P-cluster, FeMo-co, and FeFe-co of Nitrogenases
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新[8Fe-7S]簇的合成：固氮酶P簇、FeMo-co和FeFe-co核心结构之间的拓扑联系
DOI：
10.1021/ja072256b
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
K. Tatsumi
中科院分区：
文献类型：
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作者：
Y. Ohki;Y. Ikagawa;K. Tatsumi
通过 Fe{N(SiMe3)2}2 与 1 当量的 HSDmp 和 1 当量的HST提示。发现 Complex1 与甲苯中的元素硫 (S8) 反应生成一类新的 [8Fe-7S] 簇，[(DmpS)Fe4S3]2(μ-SDmp)2(μ-STip)(μ6-S) (2)。 cluster2也是由Fe{N(SiMe3)2}2+ HSDmp + HSTip + S8(8:6:10:7/8)和Fe3{N(SiMe3)2}2(μ-STip)4+ HSDmp + S8(8/3:16/3:7/8)的一锅反应产生的，其中另一个[8Fe-7S]簇， [(TipS)Fe4S3]2(μ-SDmp)2{μ-N(SiMe3)2}(μ6-S) (3) 也作为少量副产物被发现。在任一簇中，两个 Fe4S3 不完整立方烷单元通过三个阴离子配体连接，即 2 个硫醇盐 S 原子或 3 个硫醇盐 S 原子和一个酰胺 N 原子，并且一个六配位 S 原子位于 [8Fe-7S] 核心的中心。它们具有共同的 Fe(II)5Fe(III)3 氧化态，10 K 时菱形 EPR 信号表明 S=1/2 基自旋态，其中 2 的 g= 2.19、2.07 和 1.96，3 的 g= 2.13、2.06 和 1.93。讨论了固氮酶的簇 2 和簇 3 与 P 簇、FeMo-co 和 FeFe-co 的结构相关性。
A coordinatively unsaturated dinuclear iron(II) complex of bulky thiolates, [(TipS)Fe(μ-SDmp)]2(1; Tip = 2,4,6-iPr3C6H2, Dmp = 2,6-(mesityl)2C6H3), was synthesized from stepwise reactions of Fe{N(SiMe3)2}2with 1 equiv of HSDmp and then with 1 equiv of HSTip. Complex1was found to react with elemental sulfur (S8) in toluene to generate a new class of [8Fe-7S] cluster, [(DmpS)Fe4S3]2(μ-SDmp)2(μ-STip)(μ6-S) (2). The cluster2was also produced from one-pot reactions of Fe{N(SiMe3)2}2+ HSDmp + HSTip + S8(8:6:10:7/8) and Fe3{N(SiMe3)2}2(μ-STip)4+ HSDmp + S8(8/3:16/3:7/8), where another [8Fe-7S] cluster, [(TipS)Fe4S3]2(μ-SDmp)2{μ-N(SiMe3)2}(μ6-S) (3), was also found as a minor byproduct. In either of the clusters, two Fe4S3incomplete cubane units are connected by three anionic ligands, namely three thiolate S atoms for2or two thiolate S atoms and one amide N atom for3, and one hexa-coordinate S atom resides at the center of the [8Fe-7S] core. They have a common Fe(II)5Fe(III)3oxidation states, and anS=1/2ground spin state was indicated by rhombic EPR signals at 10 K withg= 2.19, 2.07, and 1.96 for2andg= 2.13, 2.06, and 1.93 for3. The structural relevance of clusters2and3to P-cluster, FeMo-co, and FeFe-co of nitrogenases is discussed.