氧原子转移和氧化水融入立方形Mn3MO (n) 复合物,基于合成,同位素标记和计算研究
Jacob S Kanady1, Jose L Mendoza-Cortes, Emily Y Tsui
1Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
Journal of the American Chemical Society
|December 18, 2012
概括
光系II中-基模型的反应性是由连接体可变性控制的,而不仅仅是的氧化状态. 这一发现揭示了氧气演变的复杂机制.
科学领域:
- 无机化学 无机化学 有机化学
- 摄影化学的使用.
- 生物化学 生物化学
背景情况:
- 光系统II中的氧进化复合体 (OEC) 对于光合作用至关重要,具有Mn{4) CaO{n} 集群.
- 了解OEC内部桥接氧化物部分的反应性对于阐明其功能至关重要.
- 作为模型,合成了结构相关的立方体Mn{3) MO{n}复合物 (M = Mn, Ca, Sc; n = 3,4).
研究的目的:
- 研究氧原子从Mn(3) MO(n) 复合体转移的机械路径.
- 探索连接物可变性和氧化状态在OEC反应性中的作用.
- 了解OEC涉及氧化物迁移的拟议机制.
主要方法:
- 合成Mn(3) MO(n) 立方体复合物.
- 使用三甲基啡 (PMe(3) 作为氧原子受体的反应性研究.
- 量子力学计算用于研究反应路径.
- (18) 用O标记实验来追踪氧化物纳入.
主要成果:
- (IV) 3 (CaO 4) 和 (IV) 3 (ScO 4) 模型对PMe没有反应.
- 甲 (III) (II) (II) (IV) (II) (IV) (IV) (II) (IV) (IV) (II) (IV) (IV) (IV) (IV) (IV) (IV) ) (IV) (IV) (IV) (IV) (III) (III) (IV) (IV) (IV) (IV) (IV) (IV) (IV) (IV) (III) (IV) (IV) (IV) (IV) (IV) (IV)) (IV) (IV) (IV) (IV) (IV) (IV) (IV) ) (IV) (IV) (IV) (IV) ) (IV) ) (IV) ) (IV) ) ) (IV) ) (IV) ) )
- 量子力学揭示了连接体 (乙酸盐) 的可变性,特别是存在Mn{\displaystyle Mn{\text{III}}),促进了氧原子的转移.
- 观察到氧化氧化物纳入部分cubane,与 (18) O标签支持氧化物迁移.
结论:
- 氧原子从Mn(3) MO(4) 库巴转移是由连接体可变性决定的,而不仅仅是的氧化状态.
- 尽管Mn{IV}{3}CaO{4}模型具有相关性,但它不具有反应性,这凸显了特定结构特征的重要性.
- 实验和计算发现支持在OEC集群中涉及氧化物迁移的机制.
相关概念视频
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