在一个金属有机框架内隔离的五坐标的二氧化添加物
John S Anderson1, Audrey T Gallagher, Jarad A Mason
1Department of Chemistry, Northwestern University , Evanston, Illinois 60208-3113, United States.
Journal of the American Chemical Society
|November 8, 2014
概括
研究人员在金属有机框架 (MOF) 中特征了一种罕见的heme-O2复合物. 这项研究揭示了结构和Fe-O2结合,为氧气运输和储存机制提供了洞察力.
科学领域:
- 无机化学 无机化学
- 材料科学 材料科学 材料科学
- 生物化学 生物化学
背景情况:
- 血红蛋白在生物氧的运输和储存中起着至关重要的作用.
- 由于它们的不稳定性,很难隔离和表征过渡性heme-O2复合体.
- 金属有机框架 (MOF) 为稳定反应性物种提供了刚性结构.
研究的目的:
- 为了结构性地描述一个短暂的5坐标的血-O2复合体.
- 为了研究Fe-O2相互作用和结合热力学.
- 证明MOFs在稳定和研究难以捉摸的中间体中的实用性.
主要方法:
- 氨酸MOF PCN-224与Fe (II) 的金属化.
- 低温O2结合和结构特征.
- 用于电子配置分析的Mössbauer光谱学.
- 可变温度O2吸附用于结合度的确定.
主要成果:
- 一个5坐标的heme-O2复合体与一个Fe(III) 中心协调到超氧化物的结构性特征.
- 莫斯巴乌尔光谱学证实了低旋转的Fe (III) 电子配置.
- 结合Fe-O2的度量为-34~4kJ/mol,明显低于可比的6坐标复合体.
- MOF使得一个通常过渡的物种的隔离和描述成为可能.
结论:
- MOF PCN-224的刚性结构有助于隔离和表征短暂的血O2物种.
- 突出了轴联体对Fe-O2结合的影响,这与生物O2运输有关.
- 这项工作展示了MOF作为研究基本化学过程的强大平台.
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