Laboratory for Computational Molecular Design, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
Phys Chem Chem Phys. 2012 Nov 21;14(43):14842-9. doi: 10.1039/c2cp42097j. Epub 2012 Sep 12.
Clusters in the (Be, B, C)@Si(n)((0,1,2+)) (n = 6-10) series, isoelectronic to Si(n)(2-), present multiple symmetric structures, including rings, cages and open structures, which the doping atom stabilizes using contrasting bonding mechanisms. The most striking feature of these clusters is the absence of electron transfer (for Be) or even the inversion (for B and C) in comparison to classic endohedral metallofullerenes (e.g. from the outer frameworks towards the enclosed atom). The relatively small cavity of the highly symmetric Si(8) cubic cage benefits more strongly from the encapsulation of a boron atom than from the insertion of a too large beryllium atom. Overall, the maximization of multicenter-type bonding, as visualized by the Localized Orbital Locator (LOL), is the key to the stabilization of the small Si(n) cages. Boron offers the best balance between size, electronegativity and delocalized bonding pattern when compared to beryllium and carbon.
（Be，B，C）@Si(n)((0,1,2+))（n = 6-10）系列的团簇与 Si(n)(2-) 等电子，呈现出多种对称结构，包括环、笼和开放结构，掺杂原子利用对比的成键机制稳定这些结构。这些团簇最显著的特点是与经典的内包金属富勒烯（例如，从外部框架向封闭原子）相比，没有电子转移（对于 Be）甚至反转（对于 B 和 C）。高度对称的 Si(8) 立方笼的相对较小的腔室更受益于硼原子的包封，而不是太大的铍原子的插入。总体而言，正如局域轨道定位器（LOL）所可视化的那样，多中心键合的最大化是稳定小的 Si(n)笼的关键。与铍和碳相比，硼在尺寸、电负性和离域键合模式之间提供了最佳平衡。
