轴联联的Mn(V) -oxo复合体的氧原子转移反应性:证据表明增强了电友和核友路径
Heather M Neu1, Tzuhsiung Yang, Regina A Baglia
1Department of Chemistry, The Johns Hopkins University , Baltimore, Maryland 21218, United States.
Journal of the American Chemical Society
|September 20, 2014
概括
阳离子捐赠者在氧原子转移反应中极大地影响 ((V) -oxo corrolazine复合物的反应性. 轴联体选择决定了反应性趋势和机械路径,为高价值催化提供了新的见解.
科学领域:
- 协调化学 协调化学
- 有机金属化学 有机金属化学
- 催化剂是一种催化剂.
背景情况:
- 合金科罗拉复合物是强大的氧化剂.
- 氧原子转移 (OAT) 反应性在氧化催化过程中至关重要.
- 了解轴联体效应是调整反应性的关键.
研究的目的:
- 为了研究阴离子轴献体对 ((V) -oxo corrolazine复合物的OAT反应性的影响.
- 阐明控制这些OAT反应的机械路径.
- 为了将实验观测与理论计算相关联.
主要方法:
- 六坐标的阳离子 ((V) -oxo corrolazine复合物的合成和特征.
- 共振拉曼光谱用于研究Mn-O振动模式.
- 对乙烯氧化反应的产品分析.
- 使用二次速率常数的动力学研究.
- 密度函数理论 (DFT) 的计算.
- 哈梅特研究使用替代的乙烯基基底.
主要成果:
- 阳离子捐赠体 (F-, N3-, OCN-) 会导致Mn-O振动频率的下移.
- 确定了硫氧化反应的反应性趋势:五坐标 ≈ 酸盐 ≈ 酸盐 < 酸盐 < 化物 < 化物 ≪ 化物.
- 不寻常的"V形"哈梅特图显示了基于基质和轴联体的氧化机制 (电友与核友) 的切换.
- 与一电子氧化复合体的比较显示出一个简单的电友机制.
结论:
- 轴联体对 ((V) -oxocorrolazine复合物的OAT反应性和机制有显著的控制作用.
- 在电友和核友氧化途径之间切换的能力是关键的发现.
- 这项研究提供了对高价值催化和氧化剂设计的基本见解.
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