Lohmeyer Lukas, Werr Marco, Kaifer Elisabeth, Himmel Hans-Jörg
Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.
Chemistry. 2022 Oct 26;28(60):e202201789. doi: 10.1002/chem.202201789. Epub 2022 Aug 31.
The field of molecular transition metal complexes with redox-active ligands is dominated by compounds with one or two units of the same redox-active ligand; complexes in which different redox-active ligands are bound to the same metal are uncommon. This work reports the first molecular coordination compounds in which redox-active bisguanidine or urea azine (biguanidine) ligands as well as oxolene ligands are bound to the same cobalt atom. The combination of two different redox-active ligands leads to mono- as well as unprecedented dinuclear cobalt complexes, being multiple (four or six) center redox systems with intriguing electronic structures, all exhibiting radical ligands. By changing the redox potential of the ligands through derivatisation, the electronic structure of the complexes could be altered in a rational way.
具有氧化还原活性配体的分子过渡金属配合物领域主要由含有一或两个相同氧化还原活性配体单元的化合物主导；不同氧化还原活性配体与同一金属结合的配合物并不常见。这项工作报道了首例分子配位化合物，其中氧化还原活性双胍或脲嗪（双胍）配体以及氧杂环戊烯配体与同一钴原子结合。两种不同氧化还原活性配体的组合产生了单核以及前所未有的双核钴配合物，它们是具有有趣电子结构的多（四或六）中心氧化还原体系，均表现出自由基配体。通过衍生化改变配体的氧化还原电位，可以合理地改变配合物的电子结构。
