作为水氧化催化剂的正方形平面四基聚烯型体的铁复合物
Lanka D Wickramasinghe1, Rongwei Zhou1, Ruifa Zong1
1Department of Chemistry, 112 Fleming Building, University of Houston , Houston, Texas 77204-5003, United States.
Journal of the American Chemical Society
|October 2, 2015
概括
新型四酸联体,2-pyrid-2'-yl) -8-pyrid-2'-yl (ppq) 促进了水的高效氧化. 铁 (III) -ppq复合物具有很高的循环频率来催化氧的演变.
科学领域:
- 协调化学
- 生物有机化学
- 催化剂
背景情况:
- 酸联体2-(pyrid-2'-yl)-8-(1′′,10′′-phenanthrolin-2′′-yl) -quinoline (ppq) 具有一个具有sp(2) 碳链接器的独特四基骨架.
- 这种结构创造了一个适合第一排过渡金属的中性,方形平面协调环境.
- 合成和表征了含有ppq和bis-phenanthroline amin (dpa) 的铁复合物.
研究的目的:
- 用ppq和dpa连接物研究铁复合物的电化学特性和催化活性.
- 为了比较单核和双核铁复合物的水氧化能力.
- 探索由这些铁复合体催化氧的演变机制.
主要方法:
- 用ppq和dpa合成和X射线结构分析
- 电化学研究以确定氧化潜力和电子转移过程.
- 使用酸作为牺牲氧化剂的催化实验,以测量氧的演变速率和循环频率.
主要成果:
- (III) (ppq) 复合体形成一个μ-oxo-bridged二元体,而 (III) (dpa) 则形成一个1:1复合体.
- 铁 (III) (dpa) 呈现两个可逆的单电子氧化波.
- 铁 (III) (ppq) 显示了两电子的氧化过程,表明了更高的氧化状态 (铁 (IV) 铁 (IV) 到铁 (V) 铁 (III)),以及随后的不成比例到FeO物种.
- 在具有牺牲氧化剂的酸性条件下,Fe (III) (ppq) 复合物与Fe (III) (dpa) 复合物 (TOF = 842 h−1) 相比显示出显著更高的氧化演变活性 (TOF = 7920 h−1).
结论:
- ppq连接体使其铁复合体具有独特的电子特性,促进多电子氧化还原过程.
- 双核Fe (III) (ppq) 复合物是氧化水的高效催化剂,其性能明显优于单核Fe (III) (dpa) 复合物.
- 这些发现突显了定制配体设计在开发人工光合作用和水分裂应用的先进催化剂方面的潜力.
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