Gas-Phase Formation of the Disilavinylidene (H₂SiSi) Transient

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• 作者：Dr. Tao Yang ; Dr. Beni B. Dangi ; Prof. Dr. Ralf I. Kaiser ; Kang-Heng Chao ; Dr. Bing-Jian Sun ; Prof. Dr. Agnes H. H. Chang ; Dr. Thanh Lam Nguyen and Prof. Dr. John F. Stanton
• 刊名：Angewandte Chemie International Edition
• 出版年：2017
• 出版时间：January 24, 2017
• 年：2017
• 卷：56
• 期：5
• 页码：1264-1268
• 全文大小：2037K
• ISSN：1521-3773

文摘

The hitherto elusive disilavinylidene (H₂SiSi) molecule, which is in equilibrium with the mono-bridged (Si(H)SiH) and di-bridged (Si(H₂)Si) isomers, was initially formed in the gas-phase reaction of ground-state atomic silicon (Si) with silane (SiH₄) under single-collision conditions in crossed molecular beam experiments. Combined with state-of-the-art electronic structure and statistical calculations, the reaction was found to involve an initial formation of a van der Waals complex in the entrance channel, a submerged barrier to insertion, intersystem crossing (ISC) from the triplet to the singlet manifold, and hydrogen migrations. These studies provide a rare glimpse of silicon chemistry on the molecular level and shed light on the remarkable non-adiabatic reaction dynamics of silicon, which are quite distinct from those of isovalent carbon systems, providing important insight that reveals an exotic silicon chemistry to form disilavinylidene.