Electrochemical investigation into the electron transfer mechanism of a diiron hexacarbonyl complex bearing a bridging naphthalene moiety
Electrochemical investigation into the electron transfer mechanism of a diiron hexacarbonyl complex bearing a bridging naphthalene moiety
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DOI：
10.1016/j.electacta.2015.02.163
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发表时间：
2015-05-01
影响因子：
6.6
通讯作者：
Liu, Xiaoming
中科院分区：
文献类型：
--
作者：
Qian, Guifen;Wang, Hailong;Liu, Xiaoming
电化学研究和化学还原的二铁六羰基配合物轴承的1，8-萘部分的桥接键，其中二茂铁基团被故意纳入进行。配合物在二氯甲烷中表现出两个还原和两个氧化过程。我们的研究结果表明，第一个还原可以归因于ECE（电化学，化学和电化学）机制与第二个电位反转。当在第一次还原中产生的单阴离子部分地经历ECE机制时，剩余的单阴离子继续接受第二电子而不涉及耦合化学反应，即所谓的EE（电化学和电化学）机制。这两种机制在电子转移过程中共存，相互竞争。通过提高扫描速率和降低温度，ECE机理中的偶联反应可以被有效地抑制，而第二还原是高度不可逆的。EE过程之后的耦合化学反应可能导致与ECE过程中产生的相同的二价阴离子。虽然化学还原和再氧化是不成功的确认两个二价阴离子之间的转换，DFT计算支持这一建议的化学反应。(C)2015爱思唯尔有限公司版权所有。
Electrochemical investigations and chemical reduction of the diiron hexacarbonyl complex bearing a 1,8-naphthalene moiety bridging linkage into which a ferrocenyl group was deliberately incorporated were performed. The complex exhibited two reduction and two oxidation processes in dichloromethane. Our results revealed that the first reduction could be assigned to an ECE (Electrochemical, Chemical and Electrochemical) mechanism with the second potential inversed. When the monoanion generated in the first reduction underwent, in part, the ECE mechanism, the rest of the monoanion continued to accept the second electron without involving a coupled chemical reaction, so called EE (Electrochemical and Electrochemical) mechanism. The two mechanisms co-existed in the electron transfer and compete with each other. By both increasing scanning rate and lowering temperature, the coupled reaction in the ECE mechanism could be effectively suppressed whereas the second reduction is highly irreversible. The coupled chemical reaction following the EE process might lead to the same dianion as that produced in the ECE processes. Although chemical reduction and re-oxidation were unsuccessful of confirming the transformation between the two dianions, DFT calculations did support this proposed chemical reaction. (C) 2015 Elsevier Ltd. All rights reserved.