Disilene has attracted considerable interest due to the trans-bending geometry which is significantly different from the planar alkene. However, the equilibrium between disilene and isomeric silylsilylene has not been fully understood. Here, we report a density functional theory (DFT) study on this equilibrium. Calculations reveal significant effects of substituent, aromaticity and base. Specifically, the parent disilene is thermodynamically more stable than the isomeric silylene. When the methoxy substituent is introduced, the corresponding silylene becomes thermodynamically more stable, which could be rationalized by the Bent's rule. Interestingly, disilabenzene becomes thermodynamically more stable than the isomeric silylene when the concept of aromaticity is taken into account. Finally, once the base is introduced, the silylene could become thermodynamically more stable than the isomeric disilabenzene. The kinetic effect of the tautomerization with several typical substituents (F, Me and OMe) has also been investigated. Some species with a bridged form have been found to have a higher thermodynamic stability over the nonbridged ones. All these findings could be particularly useful to develop the chemistry of disilenes and silylenes.

中文翻译：

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探索二烯和二硅苯及其异构体甲硅烷基的互变异构：显着的取代基，芳香性和碱效应

由于反式弯曲的几何形状与平面烯烃显着不同。但是，尚未充分理解二烯和异构甲硅烷基亚甲硅烷基之间的平衡。在这里，我们报告有关此平衡的密度泛函理论（DFT）研究。计算显示出取代基，芳香性和碱的显着影响。具体而言，母体二烯在热力学上比异构甲硅烷基更稳定。当引入甲氧基取代基时，相应的甲硅烷基在热力学上变得更稳定，这可以通过本特法则来合理化。有趣的是，当考虑芳香性的概念时，二硅烷基苯比异构甲硅烷基在热力学上更稳定。最后，一旦引入基础，亚甲硅烷基可能比异构二硅苯在热力学上更稳定。还研究了几种典型取代基（F，Me和OMe）的互变异构的动力学效应。已经发现一些具有桥联形式的物质具有比非桥联形式更高的热力学稳定性。所有这些发现对于开发二烯和硅烯的化学性质可能特别有用。