英国曼彻斯特大学的David P. Mills课题组的一项最新研究成功实现了二茂锰、二茂铁和二茂钴阴离子的分离和电子结构测定。 相关论文于2020年12月14日发表于国际顶尖学术期刊《自然—化学》。

在该文中，课题组报道了作为3d金属二茂化合物的同形家族——固态二茂铁阴离子的分离，这类化合物是由金属中心（锰，铁或钴）夹在两个庞大的Cp^ttt配体之间（其中Cp^ttt是{1,2,4-C₅H₂^tBu₃}）形成的阴离子复合物。这些对热和空气敏感的复合物在高于30°C时迅速分解；但是，课题组研究人员还是能够通过各种物理技术和从头计算来表征它们。这些数据也使得研究人员可以画出这一类金属二茂化合物的电子结构，其中包括一个19e^-衍生化二茂铁阴离子中意想不到的S=3/2高自旋基态。

据了解，二茂铁在70年前被发现标志着金属二茂化合物的开端。虽然二茂铁阳离子化合物在那之后很快就被发现了，但衍生化的二茂铁二价阳离子在2016年才被分离出来，而二茂铁的一价阴离子更是只在低温电化学研究中被观察到过。

附：英文原文

Title: Isolation and electronic structures of derivatized manganocene, ferrocene and cobaltocene anions

Author: Conrad A. P. Goodwin, Marcus J. Giansiracusa, Samuel M. Greer, Hannah M. Nicholas, Peter Evans, Michele Vonci, Stephen Hill, Nicholas F. Chilton, David P. Mills

Issue&Volume: 2020-12-14

Abstract: The discovery of ferrocene nearly 70 years ago marked the genesis of metallocene chemistry. Although the ferrocenium cation was discovered soon afterwards, a derivatized ferrocenium dication was only isolated in 2016 and the monoanion of ferrocene has only been observed in low-temperature electrochemical studies. Here we report the isolation of a derivatized ferrocene anion in the solid state as part of an isostructural family of 3d metallocenates, which consist of anionic complexes of a metal centre (manganese, iron or cobalt) sandwiched between two bulky Cpttt ligands (where Cpttt is {1,2,4-C5H2 tBu3}). These thermally and air-sensitive complexes decompose rapidly above 30°C; however, we were able to characterize all metallocenates by a wide range of physical techniques and ab initio calculations. These data have allowed us to map the electronic structures of this metallocenate family, including an unexpected high-spin S=3/2 ground state for the 19e derivatized ferrocene anion.

DOI: 10.1038/s41557-020-00595-w

Source: https://www.nature.com/articles/s41557-020-00595-w