Designing the Backbone of Hexasilabenzene Derivatives with a High Unimolecular Kinetic Stability

Abstract

It is an important subject to theoretically predict the kinetic stability of transient species. In this study, we have studied the kinetic stability of hexasilabenzene Si H and its derivatives, that is, decasilanaphthalene Si H and Li-substituted hexasilabenzene Si Li , theoretically by the artificial force induced reaction (AFIR) method combined with the rate constant matrix contraction (RCMC) method. Molecular design was further conducted to extend the unimolecular lifetime of hexasilabenzene derivatives. Although both Si H and Si Li were shown to possess shorter lifetimes than Si H , we found that the lifetimes of Si Li changed depending on arrangements of Li atoms around the monocyclic Si backbone. Based on this knowledge, we found that a compound of an atomic composition Si H Li with a planar, monocyclic Si backbone has a relatively long unimolecular lifetime. Moreover, substitution of the two Li atoms by Na atoms further increased the lifetime.

Properties and applications of polysilanes

“…The same group also synthesized cyclic silanes in parallel to their research on short linear silicon chains. While the efforts for synthesizing hexasilabenzene are still ongoing, cyclic silanes of different ring sizes have successfully been synthesized by reacting linear silanes with potassium tert‐ butoxide, thereby producing highly reactive silyl anions which can be further treated with chlorosilanes to afford the cyclosilanes . Emanuelsson et al .…”

(Li6Si5)2–5: The Smallest Cluster‐Assembled Materials Based on Aromatic Si56− Rings

“…This breakthrough triggered much experimental and theoretical research that has enriched the chemistry of stable disilenes, and has greatly motivated chemists to focus on discovering aromatic silicon compounds. Unfortunately, silicon compounds, analogous to the benchmark aromatic compound (benzene), have not yet been reported; instead, non‐flat Si 6 rings are preferred . Nonetheless, some exceptional cases of aromatic silicon ring compounds have already been reported .…”

“…Unfortunately,s ilicon compounds, analogoust ot he benchmark aromatic compound (benzene), have not yet been reported;i nstead,n on-flatS i 6 rings are preferred. [5][6][7] Nonetheless, some exceptional cases of aromatic silicon ring compounds have already been reported. [8] An example of these compounds is the synthesized lithium silicide Li 12 Si 7 , [9][10][11] whichi sm ade up of planar Si 5 rings (stacked in one-dimensional columns) and trigonal planar Si 4 stars (located in the planesb etween the Si 5 rings).…”

Understanding the Acetalization Reaction Based on its Reaction Path Network

“…The obtained multiple reaction paths form a network called reaction path network. We have developed the artificial force induced reaction (AFIR) method for obtaining reaction path networks and the rate constant matrix contraction (RCMC) method for analyzing them . In this study, we applied the AFIR and RCMC methods to the acetalization reaction with R 1 =CH 3 and R 2 =H in Scheme .…”

“…We have developed the artificial force induced reaction (AFIR) method for obtaining reaction path networks [10] and the rate constant matrix contraction (RCMC) method for analyzing them. [11][12][13][14][15] In this study, we applied the AFIR and RCMC methods to the acetalization reaction with R 1 = CH 3 and R 2 = H in Scheme 1. The search resulted in a reaction path network consisting of 162 local minima (MINs) and 599 transition states (TSs).…”