Steric and Electronic Control over the Reactivity of a Thiolate-Ligated Fe(II) Complex with Dioxygen and Superoxide: Reversible μ-Oxo Dimer Formation
作者:Roslyn M. Theisen、Jason Shearer、Werner Kaminsky、Julie A. Kovacs
DOI:10.1021/ic0491884
日期:2004.11.1
and structurally characterized. Steric repulsive interactions create unusually long FeII-N(3,4) amine bonds in 5 (mean distance=2.219(1) A). The [(tren-Et4)N4SMe2]1- ligand is unable to accommodate iron in the +3 oxidation state, and consequently, in contrast to most thiolate-ligated Fe(II) complexes, [FeII(SMe2N4(tren-Et4))]+ (5) does not readily react with O2. Oxidation of 5 is irreversible, and the
检查硫醇盐连接的五配位复合物 [FeII(SMe2N4(tren))]+ (1) 和双氧之间的反应性,以确定即使在 O2 存在时是否也能促进 O2 活化(类似于金属酶细胞色素 P450 的活化)顺式(而不是反式)与硫醇盐结合。我们小组之前的工作表明,[FeII(SMe2N4(tren))]+ (1) 在质子源存在下很容易与超氧化物 (O2-) 反应,通过 Fe(III)-OOH 中间体提供 H2O2,从而提供金属酶超氧化物还原酶(SOR)的仿生模型。将 O2 添加到 1 中得到双核 mu-氧桥 [FeIII(SMe2N4(tren))]2(mu2-O)(PF6)2.3MeCN (3)。在低温下,在质子溶剂中,可以检测到中间体,其详细信息将成为另一篇论文的主题。尽管硫醇盐配体似乎不会干扰无支撑的 mu-oxo 桥的计量参数(Fe-O= 1.807(8) A,Fe-O-Fe= 155.3(5)