A Deeper Insight into Strain for the Sila-bi[6]prismane (Si18H12) Cluster with its Endohedrally Trapped Silicon Atom, Si19H12

作者：Vach Holger^*; Ivanova Lena V; Timerghazin Qadir K; Jardali Fatme; Ha Linh Thi Le

来源：Journal of Computational Chemistry, 2015, 36(28): 2089-2094.

DOI：10.1002/jcc.24009

• ultrastability
• electron delocalization
• electron-deficient bonds
• aromaticity
• hydrogenated silicon nanoclusters

A new family of over-coordinated hydrogenated silicon nano-clusters with outstanding optical and mechanical properties has recently been proposed. For one member of this family, namely the highly symmetric Si19H12 nanocrystal, strain calculations have been presented with the goal to question its thermal stability and the underlying mechanism of ultrastability and electron-deficiency aromaticity. Here, the invalidity of these strain energy (SE) calculations is demonstrated mainly based on a fundamentally wrong usage of homodesmotic reactions, the miscounting of atomic bonds, and arithmetic errors. Since the article in question is entirely anchored on those erroneous SE values, all of its conclusions and predictions become without meaning. We provide evidence here that the nanocrystal in question suffers from such low levels of strain that its thermodynamical stability should be largely sufficient for device fabrication in a realistic plasma reactor. Most remarkably, the two "alternative," irregular isomers explicitly proposed in the aforementioned article are also electron-deficient, nontetrahedral, ultrastable, and aromatic nicely underlining the universality of the ultrastability concept for nanometric hydrogenated silicon clusters.

• 出版日期2015-10-30