Systematic Search for Isomerization Pathways of Hexasilabenzene for Finding Its Kinetic Stability

Isomerization pathways of hexasilabenzene (Si6H6) were theoretically searched by using the anharmonic-downward-distortion-following (ADD-following) method, which is a recently established systematic and automatic transition-state (TS) finding method. The search revealed the lowest barrier from the six-membered-ring structure in hexasilabenzene, and the barrier height was computed to be only 74 kJ mol−1. It follows that the six-membered ring in hexasilabenzene can easily be deformed via the TS structure. The present study identified three lower-lying TS structures around hexasilabenzene by the systematic search. These TS structures will be useful for designing a suitable substituent in a hexasilabenzene derivative for its isolation in the future, since such a substituent should be designed so that all TSs deforming the six-membered-ring backbone in a hexasilabenzene derivative are destabilized.