Gimferrer Martí, Danés Sergi, Vos Eva, Yildiz Cem B, Corral Inés, Jana Anukul, Salvador Pedro, Andrada Diego M
Institut de Química Computacional i Catàlisi, Departament de Química, Universitat de Girona c/M. Aurelia Capmany 69 17003 Girona Spain
General and Inorganic Chemistry Department, University of Saarland, Campus C4.1 66123 Saarbruecken Germany
Chem Sci. 2022 May 9;13(22):6583-6591. doi: 10.1039/d2sc01401g. eCollection 2022 Jun 7.
Low-valent group 2 (E = Be and Mg) stabilized compounds have been long synthetically pursued. Here we discuss the electronic structure of a series of Lewis base-stabilized Be and Mg compounds. Despite the accepted zero(0) oxidation state nature of the group 2 elements of some recent experimentally accomplished species, the analysis of multireference wavefunctions provides compelling evidence for a strong diradical character with an oxidation state of +2. Thus, we elaborate on the distinction between a description as a donor-acceptor interaction L(0) ⇆ E(0) ⇄ L(0) and the internally oxidized situation, better interpreted as a diradical L(-1) → E(+2) ← L(-1) species. The experimentally accomplished examples rely on the strengthened bonds by increasing the π-acidity of the ligand; avoiding this interaction could lead to an unprecedented low-oxidation state.
低价态第2族（E = Be和Mg）稳定的化合物长期以来一直是合成研究的目标。在此，我们讨论了一系列由路易斯碱稳定的Be和Mg化合物的电子结构。尽管最近一些实验实现的物种中第2族元素的氧化态被认为是零(0)，但多参考波函数分析提供了令人信服的证据，表明其具有强双自由基特征且氧化态为+2。因此，我们详细阐述了将其描述为供体-受体相互作用L(0) ⇆ E(0) ⇄ L(0)与内部氧化情况之间的区别，后者更宜解释为双自由基L(-1) → E(+2) ← L(-1)物种。实验实现的例子依赖于通过增加配体的π酸性来强化键；避免这种相互作用可能会导致前所未有的低氧化态。
