Stable meso-meso Linked 2NH-Corrole Radical Dimers as a Key Intermediate to Corrole Tape
Stable meso-meso Linked 2NH-Corrole Radical Dimers as a Key Intermediate to Corrole Tape
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稳定的介观-介观连接的 2NH-Corrole 自由基二聚体作为 Corrole Tape 的关键中间体
DOI：
10.1002/anie.202002976
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
A. Osuka
中科院分区：
文献类型：
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作者：
S. Ooi;B. Adinarayana;D. Shimizu;T. Tanaka;A. Osuka
虽然用DDQ氧化5,5',15,15'-四均基-10-10'连接的3NH-咔咯二聚体得到相应的三连接2NH-咔咯带，但使用等摩尔量的对四氯苯醌作为较温和的氧化剂导致形成10-10'-连接的中性2NH-咔咯自由基二聚体作为稳定产物。这种特殊产物的稳定性很大程度上归因于两个自旋的强烈反铁磁相互作用。这种双自由基的进一步氧化产生了可罗带，表明它作为可罗带的反应中间体参与其中。用DDQ氧化10-10'-连接的双吡啶配位的CoIIIcorrole二聚体产生了钴咯咯自由基二聚体和双连接的咔咯二聚体，两者都是带有吡啶和氰化物轴向配体的稳定化合物。这种涉及中性双自由基中间体的氧化转化是咔咯二聚体特有的独特反应机制。
While oxidation of 5,5′,15,15′‐tetramesityl‐10‐10′‐linked 3NH‐corrole dimer with DDQ gave the corresponding triply linked 2NH‐corrole tape, the use of an equimolar amount of p‐chloranil as a milder oxidant resulted in the formation of a 10‐10′‐linked neutral 2NH‐corrole radical dimer as a stable product. The stability of this peculiar product is ascribed largely to strong antiferromagnetic interaction of the two spins. Further oxidation of this diradical produced corrole tape, suggesting its involvement as a reaction intermediate to the corrole tape. Oxidation of 10‐10′‐linked bis‐pyridine‐coordinated CoIIIcorrole dimer with DDQ produced a cobalt corrole radical dimer and a doubly linked corrole dimer both as stable compounds bearing pyridine and cyanide axial ligands. This type of oxidative transformation involving neutral diradical intermediates is a unique reaction mechanism specific for corrole dimers.