[FeNO]7和[FeO2]8复合物的几何和电子结构和反应性之间的比较:密度函数理论研究的密度函数理论研究
Gerhard Schenk1, Monita Y M Pau, Edward I Solomon
1Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
Journal of the American Chemical Society
|January 15, 2004
概括
这项研究建立了一个可靠的密度函数理论 (DFT) 方法,用于铁-化复合体,这对于理解非血红素铁酶至关重要. 经过验证的DFT方法准确地模拟了铁二氧化物复合体,揭示了结合和稳定性的关键差异.
科学领域:
- 无机化学 无机化学
- 计算化学计算化学
- 生物化学 生物化学
背景情况:
- 之前的研究分析了S = 3/2 [FeNO](7) 模型复合体的电子结构,将其描述为Fe(III) 反铁磁合NO(-).
- 非血红素铁酶的化衍生物与这些模型复合体具有光谱相似性,作为可变氧中间体的类似物.
- 建立一个可靠的密度功能理论 (DFT) 方法论[FeNO](7) 复合体对于研究非血红素铁酶至关重要.
研究的目的:
- 使用实验数据建立可靠的DFT方法,用于[FeNO](7) 复合体的几何和能量.
- 将这种方法扩展到研究非血红素铁酶的[FeO(2) ](8) 复合物和反应机制.
- 为了比较[FeNO]{7}和[FeO{2}}{8}复合物的电子结构和结合.
主要方法:
- 作为一个实验基准,利用了模型复合体Fe(Me(3) TACN) ((NO) ((N(3)) 作为一个实验基准.
- 确定纯密度函数BP86具有10%的混合性质和混合的三倍-zeta/双倍-zeta基础集在实验数据和计算数据之间达成一致.
- 应用了经过验证的DFT方法来优化假设的Fe (((Me (((3) TACN) (((O (((2)) (((N (((3)) (((2)) 复合体.
主要成果:
- 经过验证的DFT方法准确地模拟了[FeNO](7) 复合体.
- 假设的[FeO(2) ](8) 复合物的优化揭示了与酸类似物相比,延长的Fe-O(2) 键和更的Fe-O-O角.
- [FeO(2)](8) 的电子结构是Fe(III) 与O(2)(-相合,具有单一的Fe(III) -O(2)(-) 键相互作用,与Fe(III) -NO(-) 中的西格玛和π键不同.
结论:
- 开发的DFT方法为[FeNO]{7}和[FeO{2}}{8}复合体提供了准确的几何和能量描述.
- 与[FeNO](7) 复合体相比,[FeO(2) ](8) 复合体表现出明显的几何和电子结构差异.
- 由于结合相互作用的差异,Fe (III) -NO (−) 形成了一个比Fe (III) -O (−2)) 稳定的引物,尽管NO更难降解.
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